review of i variation, rc, rrr and other parameters · current monitor: keithley 2000 voltage...
TRANSCRIPT
Review of Ic variation Rc RRR and other parameters
D Abraimov H W Weijers W D Markiewicz M Santos J McCallister J Jaroszynski J Jiang J Lu V Toplosky B Jarvis S
Carter Y L Viouchkov and D C Larbalestier all NHMFL
Quality Assurance procedure for 32T project
We are looking for compliance with our specification which includes
transport and geometrical properties of (Re)BCO tape using
minimum set of measurements
(Re)BCO coated conductor was purchased from SuperPower Inc
144 lengths 60 m or 110 m each
Comparison of 4K in- field Ic measured on short samples for conductors
from different manufacturers
This work was supported in part by the US National Science Foundation under Grant No DMR-0654118 DMR-0923070 and the State of Florida
Special thanks to AMSC Fujikura SuNAM SuperOx for providing samples for testing
BIIab High Jc
B at 18o to tape plane
bull One of the major limiting factors of coil performance is sharp Jc(Q) dependence in (Re)BCO
bull The minimum Ic for 32 T coil design occurs at 18o critical angle between tape plane and magnetic field of 17 T
Origins of specification for (Re)BCO conductor
Xu A et al Superconducting Science and Technology 23 014003 (2010)
BIIab
Restriction on Ic
bull Tape is being delivered in 110 or 60 m lengths making joints resistance critical
bull RRRgt50 for low resistance of stabilizer in case of quench
Dimensions bull Cu stabilizer layer should be uniform through
length and width of the tape to provide mechanical stability between pancake windings and get uniform heat propagation
bull Tape width should be uniform to avoid variations in Ic and mechanical properties difficulties in coil manufacturing
17 T
Other transport properties
Property of tape from the specification Value Units
Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle
gt256 A
n from V~I n fit gt25 -
Joints resistance measurements le230 mWmiddotcm2
Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -
Final conductor width 410 plusmn 005 mm
Final conductor Thickness le0170 mm
Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2
Substrate cross-sectional Area 020 plusmn 001 mm 2
Ag layer thickness 20 plusmn 05 mm
(Re)BCO conductor specification (short list)
Current biasing two Sorensen power supplies
bull up to 1400 A bull Analog connection
Current monitor Keithley 2000 Voltage measurement Keithley 2184A Magnet power supply Lake Shore LS 622 LabView based program for automatic B and Ibias sweeping and Ic calculation
Ic testing system for 32 T tape characterization
Oxford Instruments Superconducting 135 T (42K) magnet
sample holder
Other techniques routine QA tests
Nikon iNexiv VMA-2520 microscope
Final conductor width Surface condition Thickness profiles
Vibromet 2
Preparation cross-sections
SEM visualization with Zeiss 1540 XB Cross beam
Olympus Microscope BX41M-LED
Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area
Simplimet 3000
Ag thickness ReBCO uniformity ab-plane orientation
Transport measurements of Rc Ic of lap joints in LN self field
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
BIIab High Jc
B at 18o to tape plane
bull One of the major limiting factors of coil performance is sharp Jc(Q) dependence in (Re)BCO
bull The minimum Ic for 32 T coil design occurs at 18o critical angle between tape plane and magnetic field of 17 T
Origins of specification for (Re)BCO conductor
Xu A et al Superconducting Science and Technology 23 014003 (2010)
BIIab
Restriction on Ic
bull Tape is being delivered in 110 or 60 m lengths making joints resistance critical
bull RRRgt50 for low resistance of stabilizer in case of quench
Dimensions bull Cu stabilizer layer should be uniform through
length and width of the tape to provide mechanical stability between pancake windings and get uniform heat propagation
bull Tape width should be uniform to avoid variations in Ic and mechanical properties difficulties in coil manufacturing
17 T
Other transport properties
Property of tape from the specification Value Units
Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle
gt256 A
n from V~I n fit gt25 -
Joints resistance measurements le230 mWmiddotcm2
Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -
Final conductor width 410 plusmn 005 mm
Final conductor Thickness le0170 mm
Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2
Substrate cross-sectional Area 020 plusmn 001 mm 2
Ag layer thickness 20 plusmn 05 mm
(Re)BCO conductor specification (short list)
Current biasing two Sorensen power supplies
bull up to 1400 A bull Analog connection
Current monitor Keithley 2000 Voltage measurement Keithley 2184A Magnet power supply Lake Shore LS 622 LabView based program for automatic B and Ibias sweeping and Ic calculation
Ic testing system for 32 T tape characterization
Oxford Instruments Superconducting 135 T (42K) magnet
sample holder
Other techniques routine QA tests
Nikon iNexiv VMA-2520 microscope
Final conductor width Surface condition Thickness profiles
Vibromet 2
Preparation cross-sections
SEM visualization with Zeiss 1540 XB Cross beam
Olympus Microscope BX41M-LED
Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area
Simplimet 3000
Ag thickness ReBCO uniformity ab-plane orientation
Transport measurements of Rc Ic of lap joints in LN self field
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Property of tape from the specification Value Units
Minimum Ic at 42 K extrapolated to 17 T from Ic(B) measured at 18o angle
gt256 A
n from V~I n fit gt25 -
Joints resistance measurements le230 mWmiddotcm2
Residual Resistivity Ratio of Cu (42 to 300 K) gt50 -
Final conductor width 410 plusmn 005 mm
Final conductor Thickness le0170 mm
Cu Stabilizer Cross-sectional Area 042 plusmn 001 mm 2
Substrate cross-sectional Area 020 plusmn 001 mm 2
Ag layer thickness 20 plusmn 05 mm
(Re)BCO conductor specification (short list)
Current biasing two Sorensen power supplies
bull up to 1400 A bull Analog connection
Current monitor Keithley 2000 Voltage measurement Keithley 2184A Magnet power supply Lake Shore LS 622 LabView based program for automatic B and Ibias sweeping and Ic calculation
Ic testing system for 32 T tape characterization
Oxford Instruments Superconducting 135 T (42K) magnet
sample holder
Other techniques routine QA tests
Nikon iNexiv VMA-2520 microscope
Final conductor width Surface condition Thickness profiles
Vibromet 2
Preparation cross-sections
SEM visualization with Zeiss 1540 XB Cross beam
Olympus Microscope BX41M-LED
Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area
Simplimet 3000
Ag thickness ReBCO uniformity ab-plane orientation
Transport measurements of Rc Ic of lap joints in LN self field
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Current biasing two Sorensen power supplies
bull up to 1400 A bull Analog connection
Current monitor Keithley 2000 Voltage measurement Keithley 2184A Magnet power supply Lake Shore LS 622 LabView based program for automatic B and Ibias sweeping and Ic calculation
Ic testing system for 32 T tape characterization
Oxford Instruments Superconducting 135 T (42K) magnet
sample holder
Other techniques routine QA tests
Nikon iNexiv VMA-2520 microscope
Final conductor width Surface condition Thickness profiles
Vibromet 2
Preparation cross-sections
SEM visualization with Zeiss 1540 XB Cross beam
Olympus Microscope BX41M-LED
Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area
Simplimet 3000
Ag thickness ReBCO uniformity ab-plane orientation
Transport measurements of Rc Ic of lap joints in LN self field
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Other techniques routine QA tests
Nikon iNexiv VMA-2520 microscope
Final conductor width Surface condition Thickness profiles
Vibromet 2
Preparation cross-sections
SEM visualization with Zeiss 1540 XB Cross beam
Olympus Microscope BX41M-LED
Total conductor thickness Cu Stabilizer cross‐sectional area Substrate cross-sectional area
Simplimet 3000
Ag thickness ReBCO uniformity ab-plane orientation
Transport measurements of Rc Ic of lap joints in LN self field
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Additional techniques used for study properties of ReBCO tapes
bull 16 T Quantum design PPMS for measuring in- field
variable temperature angular dependence of Ic and R(T)
bull Rotator with split coil electromagnet 1T 77K for
measuring angular dependence of Ic in full width tapes
bull YateStar system for measuring distribution of transport
critical current at 77K 08T 50 75 100 125 150 175 200 225 250 275 300
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
T=77K
B=1 T
SP125 inner
SuNAM
I c A
Qdegree
-30 0 30 60 90 120 150 180 210
10
1T
2T
4T
8T
12T
16T
Jc
MA
cm
2
Q degree904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
RR
(30
0K
)
Temperature (K)
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Contact resistance of lap joints
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Contact resistance arranged by SP process run number Small spread within each run but has large difference between some runs
Maximum average 160 nW cm2
Peak maximum 230 nW cm2
Measurements done on standard lap joints with 80 mm overlap 80 mm
32T spec
M3-1033 M3-1062 have low Ic (4K) and high joint resistance
T=77K SF
0 20 40 60 80 1000
100
200
300
4001022-1
1024-3
1028-1
1029
1029-1
1030-1
1030-1
1030-1
1031-2
1031-2
1033-2
1033-2
1033-2
1033-2
1038
1038
1038
1038
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1038-2
1043-2
1045-3
1045-3
1045-3
1045-3
1047-4
1048-2
1048-21048-2
1048-2
1048-2
1048-2
1050-4
1052-3
1052-3
1052-3
1052-3
1060-2
1060-3
1061-2
1061-2
1061-2
1061-2
1061-2 1061-2
1061-2
1061-2
1061-2
1062-2
1062-4
1062-4
1063-2
1063-2
1063-2
1067-2
1071-2
1072-3
1078-2
1078-2
1078-2
1078-2
1084-2
1088-2
1088-2
1089-2
1094-2
1094-2
1111-2 1111-2
180-3
180-4
182-2
182-2
182-4
195-2
195-2
217-2
217-2
217-2
217-2
217-4
218-2 2
18-2
218-2
218-2
218-2
218-2
219-2 219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
219-2
236-2
239-3
239-3
239-3
M3
Co
nta
ct
resis
tan
ce
nW
cm
2
Tape
M4
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Measurements of in-field critical currents at fixed orientation
Ic(42K18oB)
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Typical Ic(B) dependence measured as field rises and decreases and current rises and decreases (LabView screenshot)
No hysteresis and no damage during field sweep
SP62 inner part of length (N5) Bias current measured from 200 A DI=2 A This field dependence was measured during 39 min Depending on Ic values field dependence takes 34 min ndash 40 min
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
8 9 10 11 12 13 14 15 16 17
250
300
350
400
450
500
550
600
650
700 UP SP60 inner
Down SP60 inner
UP SP60 out
Down SP60 out
UP SP61 out
Down SP61 out
UP SP61 inner
Down SP61 inner
UP SP62 inner
Down SP62 inner
UP SP62 out
Down SP62 out
UP SP63 out
Down SP63 out
I c
A
B T
Representative selection of Ic(B) curves measured at 42 K with 18o between sample plane and B
Orange horizontal line represents 256A minimum specified at 17T
B
Most of measured samples have Ic gt 256 A
No hysteresis in increasing and decreasing field These data have tight fit to Ic~B-a
I
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
60 80 100 120 140 160 180 2000
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
outer Ic(4K17T18
o)
inner Ic(4K17T18
o)
outer Ic(77KSF)
inner Ic(77KSF)
SP Min Ic(77KSF)
32T spec
Ic a
t 7
7K
SF
A
I c a
t 1
8o 4
2K
extr
ap
ola
ted
to
17
T A
Tape
Progress in Ic measurements SP60 ndash SP207 Data arranged by NHMFL numbers ndash delivery time line
Tapes SP65 66 79 80 were sent for developing winding technique
144 lengths 60 m or 110 m each
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
100 110 120 130 140 150 160 170 1800
10
20
30
40
50
Num
be
r of sam
ple
s
Ic(SF77K) A
Histogram of Ic measured at 77K SF
ltIcgt=130 A SD=105
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
150 200 250 300 350 400 450 500 550 6000
5
10
15
20
25
30
35
Num
be
r of sam
ple
s
Ic(4K18
o17T) A
Histogram for Ic measured at 42 K 17 T 18deg
Before we were dealing mostly with this conductor produced with M3 machine
Now we are receiving more M4 tapes suitable for top and bottom parts of the magnet
M4 16 Ic variability
M3 16 of Ic variability
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Ic(4K17T18o) data arranged as ascending SuperPower run number (we assume it as time line for each M3 M4 machine)
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
0 20 40 60 80 100 120 140 160 180
0
50
100
150
200
250
300
350
400
450
500
550
600
650
M3 inner
M3 outer
M4 inner
M4 outer
I c
at 4
2K
extr
ap
ola
ted
to
17
T A
Ic SF 77K A
We are getting two types of conductors from different SuperPower Inc machines with averaged lift factors 221 (M3) and 336 (M4)
119868119888(11987244119870 1711987918119900)
119868119888(11987234119870 1711987918119900)=159
119868119888(119872477119870119878119865)
119868119888(119872377119870119878119865)=105
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
200 300 400 500 600 700
00
01
02
03
04
05
06
07
08
09
10
M3 inner
M3 outer
M4 inner
M4 outer
a
Ic at 42K extrapolated to 17T A
M3 ltIcgt =283 A ltagt= 083 +- 004
M4 ltIcgt =450 A ltagt= 084 +- 005
No dramatic changes in a values Interpretation pinning mechanism is probably similar for low Ic and high Ic tapes
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Standard deviation 57
At 77K SF just few tapes have relative spread above 10
End to end relative variation of Ic(77K SF) 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
At 42K in-field more tapes have relative spread above 10 1
00∙
119868 119888 119894119899119899119890119903minus119868 119888 119900119906119905
119868 119888 119894119899119899119890119903+119868 119888 119900119906119905
2
End to end relative variation of Ic(4K 17T 18o)
Standard deviation 96
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Same Ic(4K17T18o) data as on previous slide but arranged as ascending lt Ic(4K17T18o) gt
Observations small difference in Ic for samples from different ends Tapes within one process have similar Ic M4 process yields tapes with higher Ic
Uniform distribution with two steps at 270A and 480A
0 20 40 60 80 100 120
150
200
250
300
350
400
450
500
550
600
650
700
ltIc(4 K 17 T 18 deg)gt
Ic(4 K 17 T 18 deg) inner
Ic(4 K 17 T 18 deg) outer
32T spec
I c(4
K 1
7T
1
8o)
A
Tape
M4
M3
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
SP64 inner SP60 inner
SEM images of ReBCO surface Larger and irregularly shaped grains on SP60 more needle like grains for SP62-64 staircase like surface for SP60 but flat surface for SP61-64
After etching Cu and Ag
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Ag
ReBCO
SEM cross-section of M4 SP129
SEM cross-section of M3 SP159
Ag
ReBCO
Different thickness for M3 and M4 machines
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Ascending lt Ic(4K17T18o) gt plot with ReBCO thicknesses
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
77K self-field critical current vs ReBCO thickness dependence
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
M3
M4
4K in-field critical current density vs ReBCO thickness dependence
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Testing geometrical tolerances
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
0 1 2 3 4
120
130
140
150
160
170
180
SP60 inner
SP60 outer
SP61 inner
SP61 outer
SP62 inner
SP62 outer
SP63 inner
SP63 outer
SP64 inner
SP64 outer
Thic
kne
ss mm
Width mm
Thickness profiles measured with Nikon microscope
All profiles are nearly the same
Optical image of typical cross section (SP 60 inner)
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Width distributions for SP60 ndash SP64 tapes are within specification
0 100 200 300 400 500 600404
406
408
410
412
414
416
SP60 inner
SP61 inner
SP62 inner
SP63 inner
SP64 inner
SP60 outer
SP61 Outer
SP62 Outer
SP63 Outer
SP64 Outer
Max
Min
W
m
m
L mm
We noticed considerable improvement of tape width uniformity which eliminates substantial part
of variations in Ic and mechanical properties
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
120 125 130 135 140 145 150 155 160 165 170 175
406
408
410
412
414
416
418
420
422
424
426
428
430
max
min
mean
32T spec Min
32T spec Max
Wid
th
mm
SP number
Conductor width variation
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
120 125 130 135 140 145 150 155 160 165 170 175140
145
150
155
160
165
170
175
180
To
tal th
ickn
ess
um
SP number
Total thickness measured with micrometer
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
120 125 130 135 140 145 150 155 160 165 170 175037
038
039
040
041
042
043
044
045
Cu
are
a
mm
2
SP number
Cu area for SP125- 166 tapes
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
RRR of stabilizer ndash parallel connection of Ag and Cu layers
RRR meets the specification
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Comparison of 4K in- field Ic for conductors from different
manufacturers
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
1 10
100
200
300
400
500
600
700
SuNAM N1
SuNAM N2
SuperOx N2
SuperOx N3
SuperOx N4
AMSC
Fujikura N1
Fujikura N2
SP77
SP129 N1
SP129 N2
SP132 N1
SP132 N2
SP127
I c
A
B T
Comparison Ic(4K B) for tapes from different manufacturers measured up to 312T Orientation field perpendicular to tape plane
B
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
1 10100
1000
SP67 inner
B at 18deg
SP83 inner
B at 18deg
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
1400A
700 A
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu) BII c
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c A
B T
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
1050 A
Fujikura
B at 18deg
GdBCO
SP89outer
B at 18deg
Comparison of Ic(4KB) in ReBCO conductors in-field up to 135T
T=4K Ic(B) measured in OX II Max field is 135T
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
GdBCO Fujikura
BIIc
SP108 out
Bi_130222_pmm120822_143_A70
OP round wire diameter 1386mm1400A
700 A
Bi_130222_pmm120822_143_A71
OP round wire diameter 1399mm
Bi-2212 round wire
SP64 innerSP63 inner
ReBCO
SP 2013 (2x50um thick Cu) BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
I c
A
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108in
Bi-2212 round wire
130222pmm12082210A66
10mm
OP130508-27x7-7-100bar-B48
diameter 06883 mm ff=10
1050 A
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Fujikura
B at 18degGdBCO
Comparison of conductor performances at 42K up to 135T Measured in OX II using up to 4 Sorensen DSC8-350E
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Manufacturer Material a at BIIc a at 18deg
SuperPower ReBCO 067-076 07-09
SuNAM ReBCO 06 06 069 068
SuperOx ReBCO 054 054 0588 059
Fujikura ReBCO 0641 069 070
AMSC ReBCO 074
Sumitomo Bi-2223 018 0164
OP processed Bi-2212- round d=138mm 033
OP processed Bi-2212 d=1154 mm 027 026 0238
OP processed Bi-2212 d=0688 mm 027
Comparison ofavalues
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
1 10100
1000
ReBCO
SuperOx B at 18o
ReBCO
SuperOx BIIc
SP108in
Bi_2212
130222_pmm
120822_143_A70
OP round wire
diameter 1386mm
Bi 2212
130222_pmm 120822_12_A69
1154 mm round wire
Bi-2212 round wire
130222pmm12082210A66
SP64 inner
SP63 inner
ReBCO
SP 2013
(2x50um thick Cu)
BII c
Bi-2223
Sumitomo 2011 tape
BIIc
SP108out
ReBCO
2013 SuNAM tape
in brass stabilizer
B at 18deg to tape
J
e A
mm
2
B T
Bi-2223
Sumitomo 2012 tape
BIIc
ReBCO
SP 2013
(2x50um thick Cu)
B at 18 deg
ReBCO
2013 SuNAM tape
in brass stabilizer
BIIc
SP108 out
Bi2212
130222pmm
120822_143_A71
OP round wire
1399mm
17T
GdBCO
Fujikura
B at 18deg
Fujikura
BIIc
GdBCO
Comparison of conductor performances at 42K Measured in OX II using up to 4 Sorensen DSC8-350E
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
0 100 200 300 400 500 600 700
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
I c(4
K B
at 1
8o)
A
Ic(4K BIIc) A
SuNAM
Fujikura
SuperOxSuperPower
X2
X15
X1
Difference in anisotropy
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
bull Comprehensive analysis of various tape properties is necessary for building reliable magnet
bull Ic measured in specific field orientation at 42K is important for predicting coil performance not testing at self-field 77 K
bull Jc(B 4K 18o) did not dropped as ReBCO thickness got 60 increase in M4 tapes
bull Transport and geometrical properties of commercially available (Re)BCO conductor from SuperPower Inc are not perfect but sufficient for making 32 T user magnet
bull Among ReBCO conductors SuperPower Inc and Fujikura have largest Ic(4K B)
bull Tapes from SuperOx show smallest among ReBCO CC a and smallest Ic anisotropy
Conclusions
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
How to choose operating current after measuring Ic in about 003 - 0018 of the conductor at 4K in-field
Assume that the distribution shown in experimental histogram is ldquouniversalrdquo through every tape from the set SP60-SP124
Here is simple statistical model Ic(x) generated with Gaussian distribution in 6000 point min Ic taken for 10000 virtual tapes
Based on standard deviation of Ic relative difference 935
Assume that minimum size of Ic non-uniformity is about 1 cm for 60m long tape
-50 -45 -40 -35 -300
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
Co
un
t
Min relative Ic change (below average per tape)
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
60 62 64 66 68 70 72 74 76 780
20
40
60
80
100
120
140
160
180
200
220
0
20
40
60
80
100
120
140
160
180
200
220
Inner Ic(4K17TBIIc)
Outer Ic(4K17T BIIc)
Inner Ic(77K SF)
Outer Ic(77K SF)
Ic S
F 7
7 K
A
I c e
xtr
ap
ola
ted
to
17
T
42
K
A
Tape Number
B
I
Ic(4K 17T BIIc) with Ic(77K SF) for selected tapes
All tapes from M3 machine
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
Relation between a values and Ic (4K 17T BIIc)
For tapes with higher Ic we observe larger a values
Ic~B-a
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
58 60 62 64 66 68 70 72 74
00
02
04
06
08
10
12
14
16
18
20
22
Inner
Outer
I c(4
K1
7T
18
o)
Ic(4
K1
7T
B
IIc)
SP number
Mean 182
Standard deviation 012 (66)
Ratio Ic(4K 17T 18o) Ic(4K 17T BIIc) has low spread from tape to tape Interpretation Angular dependence of Ic has small variation
BIIc and 18o orientations measured on different samples
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
100 150 200 250 300
00
02
04
06
08
10
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
Normalized R vs T for samples from ldquoinnerrdquo part of spools
Measurements Temperature range 300K ndash 89K SF Transport measurements were done with PPMS 3-2 samples were measured simultaneously on one pack Excitation current 10 mA DT near transition 0025K
Aim By calculating Tc from electric resistivity measurements find why Ic at SF 77K for SP60 differs from one for SP61-64
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
904 906 908 910 912 914 916 918 920
000
005
010
015
020
025
030
SP60 inner 1
SP60 inner 2
SP60 inner 3
SP60 inner 4
SP61 inner
SP62 inner
SP63 inner
SP64 inner
R
R(3
00
K)
Temperature (K)
For inner region Very narrow Tc spread and sharp transition for SP61-64 Samples from SP60 have wider and variable transition region Some SP60 samples have up to 3 ldquokneerdquo
R vs T for samples from ldquoinnerrdquo part of spools
ldquoinnerrdquo means that sample was cut from inner part of spool arrived from SP
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping
59 60 61 62 63 64 65
906
908
910
912
914
916
918 max dRdT
middle dRdT
small dRdT
Tp K
Tape number
bulk critical temperature Tc defined as maximum of dRdT
Striking difference between SP60 and SP61-64 SP60 contains several phases with different Tc ranging from 907K to 918K
Peaks of dRdT
Interpretation SP60 has non-uniform
composition with multiple (Re)BCO phases
SP 61-64 have variable through length oxygen doping