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

Recent NSTX Research Progress

• MHD

• Confinement Database

• Transport

• Edge Pedestal

• Divertor

• Sustainment

• Joint Experiments

Ned Sauthoff

for the NSTX Team

(thanks to Martin Peng and Ed Synakowski)

June 2004 NSTX Input to ITPA

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

• Data from 2001 – 3; 2004 data has extended T to 37 ± 3%

Bootstrap fraction up to

50%

• N = 5-6.2 at IP/aBT0 3

• Pulse-length up to 1s

• Appropriate for ITPA-related studies

T = 30 - 35 %

• N = 5-6 at IP/aBT0 6

• Pulse-length = 0.3-0.4s

T 20p / BT02

Menard, Sabbagh (Columbia)

With NBI Heating, NSTX Achieved Very High ,Which Helps Reveal -Dependence Physics

High-Resolution Rotation, SXR, and In-Vessel BR and BP Sensors Used to Study MHD Physics

CHERS shows v collapse

preceding collapse

SXR shows rotating 1/1mode during v decay

1/1 Island

In-vessel sensors measurerotating mode as v decays

before mode locking

Aliased n=1

rotating mode

RWM, NTM, 1/1 modes, and rotation physics of high interest to ITER

Sabbagh, Bell, Menard, Stutman

Global and Thermal E’s Are at Par with BestTokamak Data, Permitting Low-A Comparisons

• TRANSP analysis for thermal confinement

E<

ther

mal

> (

ms)

E<ITER-H98p(y,2)> (ms)

12080400

120

80

40

0

• Compare with ITER scaling for total confinement, including fast ions• L-modes have higher non-thermal component and comparable E!

Kaye

Power Balance During NBI Heating Shows Ions Approaching Neoclassical Transport ITB in ST?

• High Ti in region ~ 0.6 – 0.8 indicates i ~ i<NC>; anomalous ion heating still not

ruled out

• Large separation of i and e introduces added opportunities for transport, turbulence, and ITB-verification studies

• 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

LeBlanc et al

Wall Conditioning, Minimal Gas & ELMs Reduce Edge Density and Permit Transport Scaling Studies

• New high-resolution CHERS confirms large gradients in Ti, vi

• Recipe useful for core transport scaling studies

• A = 1.5

• = 2.3

• av = 0.6

• q95 = 4.0

• li = 0.6

• N = 5.9%·m·T/MA

• T = 40% (EFIT)34%

(TRANSP)

112600, 0.55s112600, 0.55s

R.Bell, LeBlanc, Sabbagh, Kaye

June 2004 NSTX Input to ITPA

A liquid lithium divertor concept may yield a revolutionary solution to particle and heat

management• 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

Liquidlithium

CDX-U (now LTX) liquid Li tray

Plasma Edge Studies Reveal Turbulence and“Blobs” Important to Divertor Flux Scaling Studies

He manifold

Side-viewingreentrant window

H-mode

L-mode

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)

105710

June 2004 NSTX Input to ITPA

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 s 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

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

S. Zweben

June 2004 NSTX Input to ITPA

• 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 Major participation with Oak Ridge National Laboratory

HHFW research is one of two major wave heating & current drive

elements in the program

Phase of launched wave controllable with multiple-element

antenna Electron heating demonstrated

June 2004 NSTX Input to ITPA

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 o)

• 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.

Antenna for B-X-O emission studies

G. Taylor

R. Harvey, Comp-X

MIT a collaborative partner in EBW theoryExperiments with DIII-D, MAST (UK)

Task Title NSTX Lead Status

MDC-2 Joint experiments on RWM Sabbagh RWM data being accumulated

MDC-4 NTM: aspect ratio comparison Gates Under consideration

CDB-6 Improve DB: low A Kaye Scaling data being accumulated

TP-3,4 Te~Ti, dominant electron heating; low momentum input

LeBlanc HHFW H-mode plasma produced, more planned

TP-8 Non-dimensionally similar ITB-scaling experiments

Peng

Synakowski

NSTX/MAST identity scheduled NSTX/DIII-D scaling scheduled

PEP-6 Transition threshold comparison Maingi NSTX/MAST Identity carried out

PEP-9 A-dependence, wall proximity effects Maingi NSTX measurements planned

DSOL-3 Scaling of radial transport Zweben Suggest NSTX contribution

DSOL-7 Study on separatrix density and edge density profiles

Boedo Suggest NSTX contribution

DSOL-? Time-resolved impurity deposition Skinner Propose comparison with AUG

DSOL-? Test of “dust buster” at critical places

Skinner Propose comparison with Tore-Supra

SSEP-2 Hybrid scenario development Menard DIII-D early H-mode scenario tested successfully

Status of Joint Experiments (June 2004)

Interest in CDB-2 (-scaling), etc., should be explored.