severo j. h. f . e-mail jhsevero@ifp.br
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Temporal evolution of plasma rotation measurement in tokamaks using an
optical monochromator and two photomultipliers as detector
Severo J. H. F. E-mail jhsevero@if.usp.br
Institute of Physics, University of São Paulo, Rua do Matão, s/n, 05508-900 SP, Brasil
Contents
Motivation Diagnostics for plasma rotation
measurements New technique TCABR parameters Preliminary results Conclusions
What we know about plasma rotation
CONFINEMENT TYPE
POLOIDAL ROTATION
TOROIDAL ROTATION
Low Well described by Neoclassical
Theory
Anomalous
High Anomalous Anomalous
Central toroidal plasma rotation in different tokamaks
Machine Vtor(cm/s) R (cm) a (cm) B(T) Ip(kA)
LT-3 +5.10⁵ 40 10 1 33
PLT -1,5.106 132 40 3 600
JFT-2 -1,3.106 90 25 1,8 230
TorusII +1,6.106 30 20 0,67 250
PDX ≤3.10⁵ 140 45 2,5 600
TM-4 -7.10⁵ 53 8,5 1,5 25
ISX ≈ 0 92 26 1,8 220
JET ≤ -2,4.10⁶ 296 125 2,7 2500
DIII-D -2,5.10⁶ 160 56 2,2 2000
TCA ± 2,5.10⁶ 61 18 1,5 100
TCABR -2.10⁶ 61 18 1,1 100
Diagnostics for plasma rotation measurements
Charge-exchange recombination spectroscopy
D0(nD)+AZ+ → D++A(Z-1)+(n)*
σCX= σCX (│V-Vb│)
Expensive Small time resolution
Multichannel diode array detector
Expensive
Small time resolution
New technique
462 463 464 465 466 4670.0
0.2
0.4
0.6
0.8
1.0
Inte
nsity
wavelength [nm]
2-
2
0 1
1+
A1 A
2
slit1 slit2
)(2
1 fS
Sf
PMT
PMT
Gaussian profile of spectral line
dQnndS qpIePMT 1
Experimental set-up for temporal evolution of poloidal plasma rotation measurements
Experimental set-up used for temporal evolution of plasma poloidal rotation measurements.
Spectral profiles
462 463 464 465 466 4670.0
0.2
0.4
0.6
0.8
1.0
Inte
nsi
ty
wavelength [nm]
2-
2
0 1
1+
A1 A
2
slit1 slit2
4340 4345 4350 4355 4360 4365 4370 4375 43800.0
0.5
1.0
1.5
2.0
2.5
3.0
Inte
nsi
ty o
f si
gn
al [
V]
wavelength [A]
instrument function of THR1000 monochromator
axial slitwidth = 80 m
lateral slitwidth = 80 m
Gaussian profile of spectral line. A semi-transparent mirror is used to produce a small shift in wavelength and the photomultipliers integrate different portions of the profile.
Instrumental function of the THR1000 monochromator (slitwidth 2200X80μm) obtained scanning the HgI (4358,4A) spectral line.
Doppler shift calibration
0.00 0.05 0.10 0.15 0.20 0.25 0.300
1
2
3
4
5
6
0.00 0.05 0.10 0.15 0.20 0.25 0.30-0.15-0.10-0.050.000.050.100.15
Ra
tio
o
f s
ig
na
ls
Doppler Shift [A]
Dependence between ratio of signals with Doppler shift.
TCABR plasma parameters
Plasma Major Radius 61 cm Plasma Minor Radius 18 cm Toroidal Magnetic Field 1.1
T Plasma Current ≈ 100 kA Plasma Discharge Duration
≈ 120 ms Electron Density (1.0 -
4.0).1019 m-3
Electron Temperature ≈ 600 eV
Ion Temperature ≈ 200 eV
Photograph
TCABR
Preliminary results
30 40 50 60 70 80 90 100 110 120 130 140-2.00x106
-1.75x106
-1.50x106
-1.25x106
-1.00x106
-7.50x105
-5.00x105
-2.50x105
0.00
polo
idal
vel
ocity
[cm
/s]
time [ms]
shot 22260
Temporal evolution of the TCABR poloidal rotation measured at r = 16 cm (shot 22258).
Temporal evolution of the TCABR poloidal rotation measured at r = 16 cm (shot 22260).
30 40 50 60 70 80 90 100 110 120 130-1.0x106
-8.0x105
-6.0x105
-4.0x105
-2.0x105
0.0
2.0x105
po
loid
al v
elo
city
[cm
/s]
time [ms]
Shot 22258
Preliminary results
30 40 50 60 70 80 90 100 110 120 130 140-2.00x106
-1.75x106
-1.50x106
-1.25x106
-1.00x106
-7.50x105
-5.00x105
-2.50x105
0.00
2.50x105
polo
idal
vel
ocity
[cm
/s]
time [ms]
shot 22261
Temporal evolution of the TCABR poloidal rotation measured at r = 16 cm (shot 22261).
Temporal evolution of the TCABR poloidal rotation measured at r = 16 cm (shot 22262).
30 40 50 60 70 80 90 100 110 120 130 140-1.50x106
-1.25x106
-1.00x106
-7.50x105
-5.00x105
-2.50x105
0.00
2.50x105
po
loid
al v
elo
city
[cm
/s]
time [ms]
Shot 22262
Conclusions
A new method was proposed for measurements of temporal evolution of plasma rotation in tokamaks.
The direction of poloidal velocity in the TCABR coincides
with the diamagnetic electron drift.
These results show good agreement, within experimental uncertainty, with previous results [1-2].
Reference
[1] Severo J. H. F. at al - 2003 Nuclear Fusion 43 1047. [2] Severo J. H. F. at al - 2007 Review of Scientific
Instruments 78 043509.
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