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NSTX Status and Plans. U.S. College W&M Colorado Sch Mines Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL PSI Princeton U SNL Think Tank, Inc. UC Davis UC Irvine UCLA UCSD U Colorado
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NSTX Status and Plans U.S. College W&M Colorado Sch Mines Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL PSI Princeton U SNL Think Tank, Inc. UC Davis UC Irvine UCLA UCSD U Colorado U Maryland U Rochester U Washington U Wisconsin International Culham Sci Ctr U St. Andrews York U Chubu U Fukui U Hiroshima U Hyogo U Kyoto U Kyushu U Kyushu Tokai U NIFS Niigata U U Tokyo JAERI Hebrew U Ioffe Inst RRC Kurchatov Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching ASCR, Czech Rep presented by R. J. Hawryluk for M. Ono and the NSTX Team
NSTX Just Completed 2006 Experimental Campaign Exploiting New Capabilities and Regimes • Non-axisymmetric feedback coils for error field and resistive wall mode control • Plasma rotation physics • Operated to 0.55T provided BT confinement scaling data - E(Ip or Bt)1.5 at fixed q. • High-k scattering for electron-scale fluctuation. • Optimized shaping with new PF coils for high triangularity and elongation • S • High triangularity reduced divertor heat flux and obtained small ELM regime. • Lithium Evaporator reduced density and oxygen impurities. • Successful non-inductive start-up by CHI
NSTX is Testing Active Mode Control System Copper passive conductor plates SS Vacuum Vessel • NSTX mode control system similar to US proposal for ITER • Located at vertical midplane • Coils behind vessel wall • Fields couple to nearby blanket-like passive conducting structure • Excellent test-bed for validating ITER control models • NSTX research: • Error field correction • Plasma rotation reduction/control • Active Resistive Wall Mode control internal sensors Columbia University, GA VALEN Model of NSTX 6 ex-vessel midplane control coils Plans - Using fast and improved feedback system, explore effectiveness of closed-loop EF / RWM control on the high performance long-pulse plasmas above the "no-wall" beta limit.
92 x (1/gRWM ) 6 120047 4 bN 2 0 120712 8 wf < Wcrit 4 wf/2p (kHz) 0 1.5 IA (kA) 1.0 no-wall bN > bN (n=1) 0.5 0.0 DBpun=1 (G) 20 10 0 0.4 0.5 0.6 0.7 0.8 0.9 t(s) Resistive Wall Mode Stabilized at ITER-relevant Low Rotation Plasmas • Plasma rotation reduced by non-resonant n = 3 magnetic braking • Clear demonstration of Resistive Wall Mode stabilization in low rotation plasmas.
H-mode kr=20cm-1 kr=16cm-1 10 8 kr=12cm-1 6 4 2 Frequency (kHz) kr=8cm-1 0 400 400 400 400 400 kr=4cm-1 200 200 200 200 200 0 0 0 0 0 -200 -200 -200 -200 -200 -400 -400 -400 -400 -400 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Time (s) Newly Installed High-k Scattering Diagnostic Probes Turbulence Related to Electron Transport UC Davis Unprecedented spatial resolution at electron-scale at short wavelengths due to good access Plans: Characterize local high-k turbulence and electron heat transport. Measure poloidal/toroidal rotation and determine radial electric field shear to constrain theory.
5% neutron rate decrease: 1% neutron rate decrease: NSTX Accesses ITER-relevant Energetic Particle Regime • ITER will operate in regime with many overlapping modes • Mode physics depends on Vb/VAlfvén. • High bfast(0) / btot(0) in NSTX provides drive for multiple modes • NSTX can study multi-mode regime while measuring the internal magnetic field. UCI, UCLA, JAEA Plans: Measure, identify & characterize instabilities driven by super-Alfvénic ions and associated fast ion transport.
ORNL, LLNL 117407 LSN 117432 DN 117407 LSN 117432 DN 117424 high- DN 6MW DN (L~0.40) 117424 high- DN Boundary Physics: Increased Triangularity Reduces Peak Heat Flux to Divertor Target Plans: Effects of lithium wall coating on particle recycling and improved confinement. Divertor/edge at low plasma collisionality with ITER-level heat flux.
Progress in Non-Inductive Startup and Rampup Plams: Ramp-up CHI initiated solenoid-free start-up plasmas to substantial plasma currents via heating and current drive by Neutral Beam Injection and High Harmonic Fast Wave. Long-pulse plasmas in conditions relevant to CTF and advanced operations in ITER. Ip = 160 kA on closed flux surfaces when Iinj = 0 Axisymmetric reconnection at the injector to result in formation of closed flux surfaces Univ. of Washington
Highest Elongation and Plasma Shape Factor for Advanced Operations Record elongation • Machine improvements have increased steady state shaping factor = 2.95, = 0.65, S ~ 40 = 2.3, = 0.6, S ~ 27 = 2.75, = 0.8, S ~ 37 = 2.0, = 0.8, S ~ 23 2006 2004 2005 2002-3