Supported by

1. Supported by Recent NSTX Research Progress 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 Ioffe Inst TRINITI KBSI KAIST ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching U Quebec • MHD • Confinement Database • Transport • Edge Pedestal • Divertor • Sustainment • Joint Experiments • Ned Sauthoff • for the NSTX Team • (thanks to Martin Peng and Ed Synakowski)

2. The NSTX research program is aimed at meeting two broad and related goals • Assess the attractiveness of the ST as a fusion energy concept • Component Test Facility and DEMO reactor • Grounded in integration of topical science • Use ST plasma characteristics to further a deeper understanding of critical toroidal confinement & high beta plasma physics issues 2 m NSTX Input to ITPA

3. With NBI Heating, NSTX Achieved Very High b, Which Helps Reveal b-Dependence Physics • Data from 2001 – 3; 2004 data has extended bT to 37 ± 3% bT 2m0p / BT02 • bT = 30 - 35 % • bN= 5-6 at IP/aBT0 6 • Pulse-length = 0.3-0.4s • Bootstrap fractionup to50% • bN= 5-6.2 at IP/aBT0  3 • Pulse-length up to 1s • Appropriate for ITPA-related studies Menard, Sabbagh (Columbia)

4. Aliased n=1 rotating mode High-Resolution Rotation, SXR, and In-Vessel BR and BP Sensors Used to Study MHD Physics In-vessel sensors measure rotating mode as vf decays before mode locking SXR shows rotating 1/1 mode during vf decay CHERS shows vf collapse preceding b collapse 1/1 Island Sabbagh, Bell, Menard, Stutman RWM, NTM, 1/1 modes, and rotation physics of high interest to ITER

5. 120 80 E<thermal> (ms) 40 0 0 40 80 120 E<ITER-H98p(y,2)> (ms) Global and Thermal tE’s Are at Par with BestTokamak Data, Permitting Low-A Comparisons • Compare with ITER scaling for total confinement, including fast ions • TRANSP analysis for thermal confinement • L-modes have higher non-thermal component and comparable tE! Kaye

6. Power Balance During NBI Heating Shows Ions Approaching Neoclassical Transport - ITB in ST? • Analyze power balance with TRANSP code • Use measured profiles of Te, Ti, ne, nimp, Prad • Monte-Carlo calculation of NBI deposition and thermalization • i<NC>i << e Axis Edge • High Ti in region r ~ 0.6 – 0.8 indicates i~i<NC>; anomalous ion heating still not ruled out • Large separation of iande introduces added opportunities for transport, turbulence, and ITB-verification studies LeBlanc et al

7. Wall Conditioning, Minimal Gas & ELMs Reduce Edge Density and Permit Transport Scaling Studies 112600, 0.55s 112600, 0.55s • A = 1.5 • k = 2.3 • dav = 0.6 • q95 = 4.0 • li = 0.6 • bN = 5.9%·m·T/MA • bT = 40% (EFIT)34% (TRANSP) • New high-resolution CHERS confirms large gradients in Ti, vi • Recipe useful for core transport scaling studies R.Bell, LeBlanc, Sabbagh, Kaye

8. Liquid lithium A liquid lithium divertor concept may yield a revolutionary solution to particle and heat management CDX-U (now LTX) liquid Li tray • Lithium reduces edge influxes, raising the edge temperature. • Transport theory: marginal stability of temperature gradients ==> larger edge T propagates to impressive increases in core (e.g. TFTR) • Propose to cycle liquid lithium ==> exhaust heat in the divertor region. • Lithium program on NSTX • Li pellets this year • Coatings next year • Studying viability & impact of deploying a liquid Li divertor module system with ALIST group NSTX Input to ITPA

9. 105710 Plasma Edge Studies Reveal Turbulence and“Blobs” Important to Divertor Flux Scaling Studies • Broadly Based Study: • Gas Puff Imaging views along field lines (PPPL, LANL) • Very fast camera, 105/s(PSI) • Reflectometers and edge (UCLA, ORNL) • Reciprocating probe (UCSD) • Divertor fast camera (Hiroshima U) • IR Cameras (ORNL), Filterscope (PPPL) • Modeling (PPPL, UCSD, LLNL, Lodestar) He manifold Side-viewing reentrant window H-mode L-mode

10. Physics of the edge H mode transition and scrape-off layer transport are being studied by imaging • Turbulence illuminated with gas puff at edge, imaged with ultra-fast camera (4 ms per frame) • Very new data! Task now is to quantify turbulence specta and flows, compare directly with edge turbulence theory • Scrape-off-layer intermittency underscore challenge for controlling edge particle & heat fluxes S. Zweben NSTX Input to ITPA

11. HHFW research is one of two major wave heating & current drive elements in the program • High harmonic fast waves predicted to propagate in high dielectronic constant plasmas • Heating demonstrated over a wide range in wave phase velocity • Current drive: well-suited for current drive in plasma ramp-up phase, when energetic ion population is small • Evidence for current drive obtained Phase of launched wave controllable with multiple-element antenna Electron heating demonstrated NSTX Input to ITPA Major participation with Oak Ridge National Laboratory

12. Electron Bernstein wave heating & current drive science being developed for integration & startup goals • Learn from stellarator community (W7-AS). Needed for high ne, low B (high eo) • Unique ST feature: may take advantage of high trapped particle fraction to place current where it is needed • We are studying the coupling of oblique launch, nearly circularly polarized emissions. R. Harvey, Comp-X MIT a collaborative partner in EBW theory Experiments with DIII-D, MAST (UK) NSTX Input to ITPA Antenna for B-X-O emission studies G. Taylor

13. Status of Joint Experiments (June 2004) Interest in CDB-2 (b-scaling), etc., should be explored.