ICRF Heating Experiments on DIII-D

Conference · Mon Aug 19 04:00:00 EDT 1991 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.41699· OSTI ID:6028133

Pinsker, R. I. ^[1]; Mayberry, M. J. ^[1]; Petty, C. C. ^[1]; Porkolab, M. ^[2]; Chiu, S. C. ^[1]; Prater, R. ^[1]; Baity, F. W. ^[3]; Goulding, R. H. ^[3]; Hoffman, D. J. ^[3]

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1. General Atomics, San Diego, CA (United States)
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Experiments utilizing rf power in the 32–60 MHz range to heat the DIII‐D tokamak plasma are reviewed. In the first set of experiments, a two‐element array of loop antennas oriented in the toroidal direction was used to launch ion Bernstein waves (IBW) either directly or by mode transformation from the electron plasma wave. No evidence of efficient ion heating in the central region of the plasma was found, despite an exhaustive exploration of IBW heating regimes in both limiter and diverter discharges. A strong interaction between the edge plasma and the injected rf power was observed, including perpendicular ion heating of the edge plasma correlated with parametric decay of the pump wave fields. Strong parametric decay activity and associated edge ion heating are observed under conditions theoretically expected to optimize direct IBW excitation. Detailed analysis of antenna loading data has yielded evidence of ponderomotive modification of the density profile in front of the antenna, which is theoretically predicted to be a very strong effect for this type of coupler in the ICRF. More recent experiments have employed a four-element toroidal array of poloidally-oriented loop antennas, designed for fast wave current drive experiments. Fast wave heating experiments have been performed at 32 and 60 MHz, in the fundamental hydrogen minority and in the 2Ω_H regimes. Central rf power deposition and efficient heating of the plasma are observed. Good agreement is found between the observed global heating efficiency and that predicted by scaling laws derived from neutral beam heating data.

• Research Organization: General Atomics, San Diego, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-89ER51114; AC05-84OR21400
• OSTI ID: 6028133
• Report Number(s): GA-A--20697; CONF-910869--24; ON: DE92002948
• Conference Information: Journal Name: AIP Conference Proceedings Journal Volume: 244
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ANTENNAS
BERNSTEIN MODE
BOUNDARY LAYERS
CLOSED PLASMA DEVICES
DOUBLET-3 DEVICE
ELECTRICAL EQUIPMENT
EQUIPMENT
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
LAYERS
OSCILLATION MODES
PLASMA HEATING
PLASMA SCRAPE-OFF LAYER
SCALING LAWS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
WAVE PROPAGATION