NSTX Research OperationNSTX Research Operation

June 29, 2009College W&MColorado Sch MinesColumbia UComp-XGeneral AtomicsINELJohns Hopkins ULANLLLNLLodestarMITNova PhotonicsNew York UOld Dominion UORNLPPPLPSIPrinceton UPurdue USNLThink Tank, Inc.UC DavisUC IrvineUCLAUCSDU ColoradoU MarylandU RochesterU WashingtonU Wisconsin

Culham Sci CtrU St. Andrews

York UChubu UFukui U

Hiroshima UHyogo UKyoto U

Kyushu UKyushu Tokai U

NIFSNiigata UU Tokyo

JAEAHebrew UIoffe Inst

RRC Kurchatov InstTRINITI

KBSIKAIST

POSTECHASIPP

ENEA, FrascatiCEA, Cadarache

IPP, JülichIPP, Garching

ASCR, Czech RepU Quebec

NSTXNSTX Supported by

NSTXNSTX NSTX Team Meeting 2June 30, 2009

Physics Operations going well

• Proceeding well with run

• Control– PCS control of NBI is ready for final testing next week

• This will allow Beta feedback to control NBI

• CHI– Successful coupling of Ip > 100 kA to ohmic ramp-up– The absorber coils, PFAB, will be connected to SPAS

• They will be used to mitigate absorber arcs• ISTP is imminent

NSTXNSTX NSTX Team Meeting 3June 30, 2009

Diagnostic upgrade status

– Divertor bolometer Repaired electronics received at PPPL and checked out on the bench; will be

installed this week and ready to operate next week

– BES Fabrication and initial fit up of in-vessel components complete

FDR of ex-vessel components held May 5; fabrication in progress

Fiber SOW is out for bids

UW making good progress on assembly of detector boxes

On track for completion of installation during CY09 shutdown

– MSE-LIF FDR for bay G port cover modifications held May 22; plan to modify port

cover during CY09 shutdown

Peer reviews held for design of DNB stand and DNB vacuum chamber

Redesign of tangential bolometer nearly complete

Bulk of installation will occur in CY10 shutdown

NSTXNSTX NSTX Team Meeting 4June 30, 2009

Diagnostic operations

– Maintenance Activities Replacement of defective high voltage cables for JHU multi-energy

tangential optical soft X-ray (ME-tOSXR) array

Installation of camera for LLNL Long Wavelength Extreme Ultraviolet Spectrometer (LoWEUS)

– Lyman-alpha Array Digitizer and detector amplifiers for new Lyman-alpha array received

Diagnostic is under development as collaboration with LLNL for edge measurements in the vicinity of the NSTX liquid lithium divertor

– X-ray Spectrometer Single-channel X-ray spectrometer installed on NSTX

Instrument to be used to study plasma instabilities and monitor impurities during NSTX operations

– NPA Received by Academia Sinica Institute of Plasma Physics (ASIPP) as

part of collaboration involving plasma diagnostics

NSTXNSTX NSTX Team Meeting June 30, 2009

Fabrication of LLD-1 system in progress • Laminated SS/Cu plates at vendor: moly coating starts 6/30; delivery ~7/15 • Control rack preliminary checkout in cal lab completed

• Control software development in progress using heater mockup in vacuum

Liquid Droppers installed • Unit-I and Unit-C installed. • Unit-I controls done, Unit-C controls to be tested week of 7/6

LITER09 being used for ~80% of operations• 5th reload completed; units parked in vessel behind shutters

- loading on: 03/09/09; 04/18/09; 05/06/09; 05/31/09; and 06/16/09. On 05/31/09, only Bay F loaded.

Divertor Region Sample Probe yielding data• Analyzed deposition in situ with Thermal Desorption Spectroscopy

(TDS)• Surface physics and chemistry of samples under analysis at Purdue• Remote control tested and operative

UCSD Fast Probe upgraded• Exchanged the head/shaft combo with a new one • Installed newest generation of vacuum boards; more robust• Tested all our data processing with the new MDS+ server

Research Operation Division Boundary Physics Operations

NSTXNSTX NSTX Team Meeting 6June 30, 2009

Status of HHFW System and Edge Heating Results - Near Term HHFW Plans

• Antenna upgrade is complete and vacuum conditioning is starting

• Fast wave edge loss channel has been detected with fast camera

• Infrared camera measurement of heat flux to outer divertor plate indicates hundreds of kilowatts are being lost at elevated edge density for H-mode cases studied to date

• Plan to study this edge loss process versus edge density and IP (magnetic pitch) for L-mode and H-mode discharges this experimental campaign

NSTXNSTX NSTX Team Meeting 7June 30, 2009 7

Previous RF Feed Previous RF Feed

Previous GroundPrevious Ground

New Ground New Ground

Additional RF Additional RF FeedFeed

HHFW System Upgrades in 2009-10 Should Double Coupled Power & Increase Resilience to ELMs

• 2009 Double-feed upgrade 2009 Double-feed upgrade shifts ground from end to shifts ground from end to strap center.strap center.

• Lower strap voltage for a Lower strap voltage for a given strap current:given strap current:– Double power per strap for Double power per strap for

the same plasma load.the same plasma load.– Permits larger plasma-Permits larger plasma-

antenna gap (lower load)antenna gap (lower load)

• ELM resilient system will be ELM resilient system will be

added in 2010 for H-mode added in 2010 for H-mode operation.operation.

NSTXNSTX NSTX Team Meeting 8June 30, 2009 8

Fast waves propagating in the SOL are heating the tiles on the outer divertor plate

“Hot region is much more pronounced at -90° than at -150°- Edge power loss is probably greater at -90°- Also, suggests fields move away from wall at -150° along with the onset

densityTime for “hot” spot to decay away is ~ 20 ms at -90° and ~ 8 ms at -150°

PRF ~ 1.8 MW, PNB = 2 MW, IP = 1 MA, BT = 5.5 kG

NSTXNSTX NSTX Team Meeting 9June 30, 2009 9

Infrared measurements show significant RF power deposition in the hot zones

CHI Gap RF Hot zone

-90°

-150°

Infrared Measured Heat FluxShot 130621 (0.41562 s - 0.43762 s)

Visible Camera with Subtraction

IR results indicate several hundreds of kW deposited on outer divertor plate Deposition for -90° farther out along with onset density

130621

130608

Edge outer divertor plate

CHI gap

IRview

-90°