Fast wave current drive on DIII-D

Journal Article · Thu Feb 01 04:00:00 EST 1996 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.49574· OSTI ID:286156

deGrassie, J S; Petty, C C; Pinsker, R I; Forest, C B; Ikezi, H; Prater, R; Baity, F W; Callis, R W; Cary, W P; Chiu, S C; Doyle, E J; Ferguson, S W; Hoffman, D J; Jaeger, E F; Kim, K W; Lee, J H; Lin-Liu, Y R; Murakami, M; ONeill, R C; Porkolab, M ; Rhodes, T L; Swain, D W ^[1]

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1. General Atomics, San Diego, California 92186 (United States)

The physics of electron heating and current drive with the fast magnetosonic wave has been demonstrated on DIII-D, in reasonable agreement with theoretical modeling. A recently completed upgrade to the fast wave capability should allow full noninductive current drive in steady state advanced confinement discharges and provide some current density profile control for the Advanced Tokamak Program. DIII-D now has three four-strap fast wave antennas and three transmitters, each with nominally 2 MW of generator power. Extensive experiments have been conducted with the first system, at 60 MHz, while the two newer systems have come into operation within the past year. The newer systems are configured for 60 to 120 MHz. The measured FWCD efficiency is found to increase linearly with electron temperature as {gamma}=0.4{times}10{sup 18}{ital T}{sub {ital e}0} (keV) [A/m{sup 2}W], measured up to central electron temperature over 5 keV. A newly developed technique for determining the internal noninductive current density profile gives efficiencies in agreement with this scaling and profiles consistent with theoretical predictions. Full noninductive current drive at 170 kA was achieved in a discharge prepared by rampdown of the Ohmic current. Modulation of microwave reflectometry signals at the fast wave frequency is being used to investigate fast wave propagation and damping. Additionally, rf pick-up probes on the internal boundary of the vessel provide a comparison with ray tracing codes, with clear evidence for a toroidally directed wave with antenna phasing set for current drive. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: General Atomics
• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-89ER51114; AC05-84OR21400; W-7405-ENG-48
• OSTI ID: 286156
• Report Number(s): CONF-9505105--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 355; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
CURRENT-DRIVE HEATING
ELECTRON TEMPERATURE
KEV RANGE 01-10
MHZ RANGE 01-100
MHZ RANGE 100-1000
NON-INDUCTIVE CURRENT DRIVE
SHIELDING
TOKAMAK DEVICES
WAVE PROPAGATION