LARP Cable R&D 2.4.1.2

D.R. Dietderich

LBNL

Outline

• Status of cables for LARP – TQ – LR and SQ

• Critical current testing cables – At NHMFL with transverse pressure

• Loading at LHe temperatures

– At CERN in the FRESCA facility (G. Ambrosio on Friday) • Loading at room temperature

Cable Fabrication

WBS code 2.4.1.2.1Description Cable R&D, Cable Fabrication

Item description No. ofunits

Cable FabricationTQ magnets

Practice cableProduction TQC02 F-EProduction TQS03Production TQC03

NbTi Leader F

SQ magnetsSQ-03

SR & LR magnets Production SR01 F

NbTi Leader FCu Practice cable FProduction LR01 F-EProduction LR02

R&D CablesNew RRP strand 84/91

New RRP strand 108/127

TQ Fully Keystoned cableNarrow

Very Wide Keystoned cableFully Keystoned w/core

Partial Keystoned w/o core

TQ Cable Parameters

Parameters Units Parameter Tolerance

Strands in cable No. 27 NA

Strand diameter mm 0.7 +/- 0.003

Width mm 10.077 max. +0.000, -0.100

Thickness mm 1.26 +/- 0.010

Keystone angle deg. 1.0 +/- 0.10

Minor Edge of 3 TQ Cables

 

928R

939R

940R

Large edge facets on cable 939R

Minor Edge of 939R & 940R

• 939R -- The two strand just in from the edge of the cable have at least 5 sheared sub-elements

• 940R -- The two strand just in from the edge of the cable are OK

Cable Observations

• All three cables are in specification of thickness, width, and keystone angle

• Cable 939R– Has a very large facet on minor edge and sheared sub-elements– Two facets on major edge

• Cable 940R– Facets on major and minor edge are consistent with other TQ

cables such as 928R.

Why are the cables different?

• Its not clear why cables 939R and 940R are different– Different strand

• Ic at 12T of strand: 8220 (939R) is higher than 8647 (940R)

– This suggest sub-elements with different composition» 8220 may have more Sn

• Pitch Length different: 40mm vs. 14mm.

– Anneal prior to re-rolling of cable may have been different• Cable 939R was double the mass of 940R

New Procedures and Documention – Draft 4-25-2006

• First cable pass– Stop after 3-5m

• Evaluate facets on edge of cable and cable parameters from CMM• Mount sample for metallography and inspect sub-elements• Place cable sample in achieves

– Make necessary adjustments to Turks head and proceed with run

• Annealing of cable– Annealing conditions

• 200-210 C for 2 h• The annealing box will be purged with 40 cf of Argon prior to the anneal • A thermocouple will be placed into the cable stack on the take-up spool to monitor cable temperature

• Second cable pass– Install 2nd set of rolls 50 microns wider than those used in the first pass–Stop after 3-5m

•Evaluate facets on edge of cable and cable parameters from CMM• Mount sample for metallography and inspect sub-elements

– Make necessary adjustments to Turks head and proceed with run

• Samples – Take a sample for metallography– Ship 2.5m of cable to BNL and FNAL. – Evaluate cable

• If qualified then insulate and ship to Lab winding coils

Developing Integrated Note to Become Traveler

• Will combine the following– Cover page will be the typical LBNL cable document– Cable specifications and requirements – Confirmation of inventory in strand map– Re-spooling procedure and re-spooling map– Cable run check list– Cable evaluation procedures before starting run– Heat treatment profile for the cable anneal–

Possible Strand for TQ1a

Billet Type StackDiameter

(mm)Weight

(kg) Magnet7933 RRP 60/61 0.7 25.7 $ TQ7946 RRP 60/61 0.7 22.7 $ TQ

8079 RRP 90/91 0.7 21 R&D TQ

Conductor needed: 25kg minimum

Jc (12T, 4.2K): 2,000-3,000A/mm2

RRR: >50

Stability Current Is(4.2K): >650A

B8079 90/91 0.7mm

ID B8079- L(m)1 9122 9094 2745 2117 1242

tot L(m) 3548tot wt(kg) 12.1

Strand 8079 90/91 stack

Prototype TQ Cable with 90 Sub-elements

• Cable fabricate TQ style cable with Oxford RRP with with 90 sub-elements

Sub-Scale Cable Parameters

Item Value Tolerance

Number of strands 20 NA

Strand Diameter 0.7 mm +/- 0.002 mm

Thickness 1.276 mm +/- 0.010 mm

Width 7.793 mm +/- 0.050 mm

Pitch Length 54.0 mm +/- 3.0 mm

Sub-Scale Cable

• Cable is rectangular and narrow • Easy to make mechanically stable for magnet winding.

• Light deformation of strands at the edge • Low risk of damaging strand

SM-01 Magnet Performance

Cable 809

Strand ORe 143c

• Coils SC-01 and 02

• RRR 35-40

• Coils very stable

• Achieved short sample

SM-01a & SM-01b

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 5 10 15 20 25 30Ramp #

Iq (

A)

Iq SC-01bIq SC-02bIq SC-01Iq SC-02

short sample limit

Edge of Cable 926R for SQ-02 andCable 935R for SR-01

926R MJR 935R MJR

Stability Current (Is) for Strand 8220 – Sub-scale and TQ type cables

BNL & FNAL Data0

200

400

600

800

1000

1200

1400

0 5 10 15 20 25 30

BNL & FNAL Sample No.

Is (

A)

8220 Virgin

933R ES

935R ES

FNAL 935R

FNAL 933RStrands Damaged

XS - Sub-Scale CableVirgin

Magnet Limit

Critical Current (Ic) for Strand 8220 – Sub-scale and TQ type cables

Ic (12T,4.2K)

0

100

200

300

400

500

600

700

0 5 10 15 20 25 30

Sample No.

Ic (

A)

8220 Virgin

933R ES

935R ES

FNAL

Strands Damaged

635-640 C650-680 C

BNL & FNAL Data

Performance of Cable 935R in Transformer Test

0

100

200

300

400

500

600

700

800

900

1000

1100

0 5 10 15 20

Test Number

Iq

Non-Impreg

Impreg

Sub-scale cable 935R strand 8220

Data Normalized to Number of Strands

FNAL Data

Strand Data for LR cables – Billets 8647 and 8648

Ic (12T, 4.2K)

540

545

550

555

560

565

570

575

580

RRP-8647-3

RRP-8647-1

RRP-8647-3

RRP-8648-2B

RRP-8648-1

RRP-8648-10

Billet Number

Ic (

A)

Is

Is

0

200

400

600

800

1000

1200

1400

RRP-8647-3

RRP-8647-1

RRP-8647-3

RRP-8648-2B

RRP-8648-1

RRP-8648-10

Billet Number

Is (

A)

Is

RRR 200 BNL data

Cable 942RCable 942R

LR Cable Production

• Cu dummy cable fabricated week of 4/3/2006 – Has been annealed – Needs to be re-rolled

• Production Runs:

– First UL of Nb3Sn (billet 8647) cable fabricated week of 4/17/2006• Annealing and re-rolled week of 4/24/2006

– Second UL of Nb3Sn (billet 8648) cable will be fabricated in May 2006

Cable Testing

Unit MATERIALItem description of No. of

Measure unitsCable R&D, Cable Test

Transformer Test LOT 12BNL Test LOT 6

WBS code 2.4.1.2.2Description Cable R&D, Cable Test

Performance of Cable 935R in Transformer Tests

0

100

200

300

400

500

600

700

800

900

1000

1100

0 5 10 15 20

Test Number

Iq

Non-Impreg

Impreg

Sub-scale cable 935R strand 8220

Data Normalized to Number of Strands

FNAL Data

Transverse Pressure Measurements

Single superconducting strand in a cable made of Cu wire

Correlate to prototype magnet performance to determine if stress limiting

Need to measure more cables under transverse pressure

0

0.2

0.4

0.6

0.8

1

1.2

0 40 80 120 160 200 240Transverse Pressure (MPa)

No

rma

lize

d C

riti

ca

l Cu

rre

nt

MJR 86.6% PF

MJR 88.5% PF

PIT 85.6% PF

PIT 86.7% PF

PIT 88.6% PF

PIT 91.5% PF

ITER 88.6% PF

ITER 89.5% PF

12 T

E. Barzi, FNAL

LARP Meeting April 2006 LARP Magnet Program – D.R. Dietderich

Cross-Section of Samples

NHMFLU. Twente

Cable

LARP Meeting April 2006 LARP Magnet Program – D.R. Dietderich

Sample and Magnet Orientation for Tests NHMFL

Two Nb3Sn cablesin 304 SS holder in radial access port

Split pair solenoid

NHMFL Loading Piston and Bellows

LARP Meeting April 2006 LARP Magnet Program – D.R. Dietderich

Loading Fixture in Magnet at NHMFL and Sample

Sensitivity of Cable to Transverse Stress

3002502001501005006

7

8

9

10

11

12

13

14

Load

Unload

Load

Unload

Results for D20 Cable

Stress (MPa)

Ic(kA)

TWCA

IGCUnload

UnloadTWCALoaded

IGCLoaded

11 T

LBL Cable # 523 MJR-TWCA

LBL Cable # 522 IGC-Int. Tin

D-20

HD-1

RRP-Oxford

NHMFL Test150mm uniform field122mm load length

MJR recover Ic when unloaded

Less Cu more Nb3Sn in subelementNb3Sn filaments sinter together

Stress Issue?B

Nb3Sn Cable

+

LARP Meeting April 2006 LARP Magnet Program – D.R. Dietderich

Difference In Testing Facilities

• Twente•Single U-shaped Cable

– Current redistribution

•Load length only 40 mm– 90 mm cable pitch

•Difficult to guarantee uniform loading

•Regions outside of loading area may not be constrained

•Nb-Ti leads soldered directly to Nb3Sn

•Voltage taps soldered to individual strands

NHMFL•Two straight cables

•Load length 122 mm– 90 mm cable pitch

•Uniform loading due to beam configuration

•Sample constrained on all sides

•Solder box method developed for D20

•Cu-Sn alloy foil developed for LBNL magnets

Summary

LR cable production Cu dummy cable and NbTi leader material have been made First UL is being evaluated Second UL will be fabricated by the middle of June 2006

TQC-02 cable production 6 UL have been fabricated

4 UL did not pass evaluation Therefore a new cable must be fabricated by the middle of June 2006

Cabling of strand with larger number of sub-elements is feasible

Still need to explore fabrication limits of cables with different keystone angles and widths

Transverse stress on cables: Need to perform full size cable tests to complement the strand tests now being performed