S.A. Sabbagh, J.M. Bialek, S.P. Gerhardt, R.E. Bell, J.W. Berkery, B. LeBlanc, J.E. Menard, et al.
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NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al. S.A. Sabbagh, J.M. Bialek, S.P. Gerhardt, R.E. Bell, J.W. Berkery, B. LeBlanc, J.E. Menard, et al. XP1023: Optimized RWM control for high < N > pulse at low collisionality and l i Supported by Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U Niigata U Tsukuba U U Tokyo JAERI Ioffe Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching U Quebec NSTX Physics Meeting April 26 th , 2010 Princeton Plasma Physics Laboratory Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA Princeton Plasma Physics Laboratory V1.0
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Supported by. Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U - PowerPoint PPT Presentation
Transcript of S.A. Sabbagh, J.M. Bialek, S.P. Gerhardt, R.E. Bell, J.W. Berkery, B. LeBlanc, J.E. Menard, et al.
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
S.A. Sabbagh, J.M. Bialek, S.P. Gerhardt, R.E.
Bell, J.W. Berkery, B. LeBlanc, J.E. Menard, et al.
XP1023: Optimized RWM control for high <N>pulse at low collisionality and li
Supported by
Columbia UComp-X
General AtomicsINEL
Johns Hopkins ULANLLLNL
LodestarMIT
Nova PhotonicsNYU
ORNLPPPL
PSISNL
UC DavisUC Irvine
UCLAUCSD
U MarylandU New Mexico
U RochesterU Washington
U WisconsinCulham Sci Ctr
Hiroshima UHIST
Kyushu Tokai UNiigata U
Tsukuba UU Tokyo
JAERIIoffe Inst
TRINITIKBSI
KAISTENEA, Frascati
CEA, CadaracheIPP, Jülich
IPP, GarchingU Quebec
NSTX Physics MeetingApril 26th, 2010
Princeton Plasma Physics Laboratory
Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
Princeton Plasma Physics Laboratory
V1.0
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
XP1023: Optimized RWM feedback control for high <N>pulse at low collisionality and li
• Motivation Next-step ST devices (including the planned upgrade of NSTX) aim
to operate at plasma collisionality and li below usual NSTX levels 2009 XP948 showed significantly higher RWM activity, lower N
limit, in reduced li plasmas (li ~ 0.45 and below)
• Overall Goal Improve reliability of RWM stabilization at low li, understand impact
of reduced plasma collisionality using new LLD capability
• Progress Generated reduced li target plasmas Generated unstable RWMs without manipulating plasma rotation Utilized new N feedback, new RWM control algorithms Insufficient E to complete XP, but developed target for XP1020
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
NSTX XP948 operated very low li, with high probability of RWM – can these plasmas be better controlled?
• Advancement in N/li toward targets 2006 value: 11 XP948 (2009): 13 ST-CTF: 16
• Uncontrolled growing RWM occurred in about 50% of shots ST-CTF target must
be sustained indefinitely
• What value of li is the current-driven kink limit (unstable any )? DCON n = 1 no-wall
limit for 135111 low: N = 2.8 (li = 0.38)
XP948: S.P. Gerhardt
N
0
1
2
3
4
5
6
7
8
0 0.2 0.4 0.6 0.8 1li
ST-CTF
ARIES ST (DEMO)
NSTXdatabase
XP948
Uncontrolled RWM
Stable / controlled RWM
N/li 13 12 11 10
DCON Nno-wall
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
Low-frequency MHD signal fromintegratedodd-ndBdt fromhign-n array sensors
0.56 0.57 0.58 0.59 0.60Seconds
-30-20-10
010
Gau
ss
Low-passfilteredRWM sensorangular positionofmaximumplasman=1BP upper
100
200
300
Deg
ree
s
Low-passfilteredRWM sensoramplitudeofplasman=1BP upper
0.002
0.004
0.006
0.008
Tesla
Normalizedtoroidalbeta
012345
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\ENGINEERING::IP2/1e6
00.20.40.60.81.01.2
amp
eres
137722Shots:XP1023: unstable RWM created in low li target plasma
• Clear unstable RWMs produced Although E was low, unstable RWM generated without n = 3 braking
137722
unstable RWM
RWM rotation
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
0
1
2
3
4
5
6
7
8
0.0 0.2 0.4 0.6 0.8 1.0
XP1023: new low li targets generated with reduced n = 1 ideal no-wall beta limit
• Ip = 1.0 and 1.1 MA target plasmas
• No-wall beta limit significantly reduced Ip = 1.1MA target:
DCON n = 1 no-wall limit low for 137722: N < 2.8 (li ~ 0.4)
With single LITER, this target was not reliably reproduced last Thursday to use in XP1020
N
li
ST-CTF
ARIES ST (DEMO) N/li 13 12 11 10
“usual” n = 1 N
no-wall limit
Filled = overthe no-wall limit(Ip = 1.1 MA)
Reduced Nno-wall < 2.8
NSTX XP1023 (Optimize RWM control low li, ) first run summary 4/26/10 - S.A. Sabbagh, et al.
0
1
2
3
4
5
6
7
8
0.0 0.2 0.4 0.6 0.8 1.0
bet
aNXP1023: new low li targets generated with reduced
n = 1 ideal no-wall beta limit
• Ip = 1.0 and 1.1 MA target plasmas
• No-wall beta limit significantly reduced Ip = 1.1MA target:
DCON n = 1 no-wall limit low for 137722: N < 2.8 (li ~ 0.4)
Ip = 1.0MA target: DCON n = 1 no-wall limit low for 137804: N = 3.4 (li ~ 0.5)
• Unstable RWM without n = 3 braking Ip = 1.0 target was
reliable: moved on and used it in XP1020
N
li
ST-CTF
ARIES ST (DEMO) N/li 13 12 11 10
“usual” n = 1 N
no-wall limit
Filled = overthe no-wall limit
Ip = 1.1 MAN
no-wall < 2.8
Ip = 1.0 MAN
no-wall = 3.4
