C. Kessel and E. Synakowski Princeton Plasma Physics Laboratory For the NSTX National Team
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Transcript of C. Kessel and E. Synakowski Princeton Plasma Physics Laboratory For the NSTX National Team
C. Kessel and E. SynakowskiPrinceton Plasma Physics Laboratory
For the NSTX National Team
APS Division of Plasma Physics MeetingOctober 27-31, 2003
Integrated Scenario Modeling of NSTX Advanced Plasma
Configurations
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 TokyoIoffe Inst
TRINITIKBSI
KAISTENEA, Frascati
CEA, CadaracheIPP, Jülich
IPP, GarchingU Quebec
Non-inductively Sustained, High for flattop >> J Integrated
Advanced ST Plasmas
Ip = 1.0 MA, BT = 0.36 T, N = 8.85, = 41%, PNBI = 4 MW,
PHHFW = 3 MW, PEBW = 3 MW
High and N Operating Targets for flattop > E ST Physics at High
Non-solenoidal Current Rampup Basis for Future ST Devices
Non-inductively Sustained for flattop > J Current Drive Techniques
NBI + HHFW, HHFW only, and HHFW+EBW
Integrated Scenario Modeling is Focused on NSTX Advanced ST Milestones
Shot 109070 Provides Basis for Integrated Scenario Modeling in TSC
Shot 109070 was chosen as a good prototype for longer pulse NBI scenarios
tflat > J for Ip and INI / IP > 50%
N = 5.9, H98 = 1.2
TSC benchmark simulation of 109070
TRANSP, S. Kaye
Strong Suppression of HHFW CD from NB Fast
Ions and for Ti/Te >1
Beam ions absorb 50-98% of HHFW power ----> seen in beam ion energy on experiment
Thermal ions absorb 0-40% of HHFW power ----> no experimental verification so far
Most of the HHFW power is absorbed before waves reach axis, low k|| suffers most
However, HHFW current drive without NBI reaches up to 140 kA/MW
No CD is assumed from HHFW in scenarios that include NBI
NSTX Can Operate for Several Current Relaxation Times Depending on the TF Field
0.0
1.0
2.0
3.0
4.0
5.0
6.0
3 3.5 4 4.5 5 5.5 6
Bt (kG)
Tim
e,
sec
J = 230 ms (109070)
J = 670 msNon-inductively Sustained, High
J = 500 ms Non-inductively Sustained
J oa
212 neo
,neo f Te , f t ,*,Zeff
Accessible TF Coil flattop time
4 J
2 J
=2.6,=0.8+=2.6,=0.4=1.9,=0.8
PF1 Coil Modification Leads to Simultaneous High Elongation and High Triangularity
Present shaping capability PF1 Modification
EBW CD Provides Off-Axis Current Profile Control
G. Taylor, PPPLB. Harvey, CompX
• Lower BT to access high and N values and long pulse lengths
• Inject– 4 MW NB heating and CD on axis– 3 MW HHFW heating (no CD)– 3 MW EBW heating and CD off-axis
• Utilize simultaneous high elongation and high triangularity from PF1 modification
• Assume density control and slight density peaking near plasma edge from lithium pellets or pumping, n(0)/<n> = 1.1
Time-Dependent Simulations of Non-inductively Sustained, High Plasmas in TSC
Non-Inductively Sustained, High PlasmaIntegration Target is Reached
Ip = 1.0 MA, Bt = 0.36 TIBS = 430 kA, INB = 430 kAIEBW = 100 kA = 2.55, = 0.83qcyl = 2.5, li(1) = 0.4
= 41.3%N = 8.85E = 37 msH98 = 1.5
ion
electron
poloidal flux
n(0) n
EBW off-axis current critical for ballooning stability
Reach = 41%, N = 8.85, for 4 J with Ip = 1 MA, BT = 0.36 T
Stable to high-n ballooning* and n=1 kink modes with outboard wall at 1.5a
PF1 coil modification critical to accessing high N by providing high and high together
* except in pedestal region
Pressure Profile and Current Profile Lead to StableHigh Plasma with fNI ≈ 1, Sustained for 4J
V/ Vo
Further Investigations and Development for Integrated Scenario Modeling
• HHFW CD efficiency– Fast ion absorption– Thermal ion absorption– Full wave (AORSA) and
ray-tracing benchmarks
• EBW CD– Continue modeling and
parameter dependences
• Plasma transport– Continue to rely on expt.
’s as discharges move closer to scenarios
– Use NSTX specific global scaling
– Pursue a Low A predictive transport model
• NBI analysis– Apply TRANSP beam
analysis to TSC high cases
• MHD stability– Vertical stability/control
of high plasmas– Identify more accurate -
limits ---> conductors geometry, plasma rotation, higher n RWMs, RWM feedback, FLR & flow stabilization for high-n
NSTX is Using Integrated Scenario Modeling to Plan Future Experiments
• Advanced ST plasmas have been identified– Non-inductively Sustained for flattop > J,
– Non-solenoidal current rampup,
– High and N Operating Targets,
– Non-inductively Sustained, High for flattop ≈ 4 J,
• Ip = 1.0 MA, BT = 0.36 T, N = 8.85, = 41%, PNBI = 4 MW, PHHFW = 3 MW, PEBW = 3 MW
• Critical tools to access Advanced ST plasmas– HHFW heating with NBI, and heating/CD without NBI on/near-
axis– EBW CD off-axis– Strong plasma shaping through PF coil modification– Density control thru pumping or lithium