Fast wave current drive in neutral beam heated plasmas on DIII-D

Journal Article · Tue Apr 01 04:00:00 EST 1997 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.53413· OSTI ID:587023

Petty, C C; Forest, C B; Pinsker, R I; deGrassie, J S ^[1]; Baity, F W ^[2]; Callis, R W; Cary, W P; Chiu, S C; Freeman, R L; Gohil, P; Groebner, R J; Ikezi, H ^[1]; Jaeger, E F ^[2]; Lin-Liu, Y R ^[1]; Murakami, M ^[2]; Porkolab, M ^[3]; Prater, R ^[1]; Rice, B W ^[4]

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1. General Atomics, San Diego, California 92186 (United States)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
3. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
4. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

The physics of non-inductive current drive and current profile control using the fast magnetosonic wave has been demonstrated on the DIII-D tokamak. In non-sawtoothing discharges formed by neutral beam injection (NBI), the radial profile of the fast wave current drive (FWCD) was determined by the response of the loop voltage profile to co, counter, and symmetric antenna phasings, and was found to be in good agreement with theoretical models. The application of counter FWCD increased the magnetic shear reversal of the plasma and delayed the onset of sawteeth, compared to co FWCD. The partial absorption of fast waves by energetic beam ions at high harmonics of the ion cyclotron frequency was also evident from a build up of fast particle pressure near the magnetic axis and a correlated increase in the neutron rate. The anomalous fast particle pressure and neutron rate increased with increasing NBI power and peaked when a harmonic of the deuterium cyclotron frequency passed through the center of the plasma. The experimental FWCD efficiency was highest at 2 T where the interaction between the fast waves and the beam ions was weakest; as the magnetic field strength was lowered, the FWCD efficiency decreased to approximately half of the maximum theoretical value. {copyright} {ital 1997 American Institute of Physics.}

• Research Organization: General Atomics
• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-89ER51114; AC05-96OR22464; W-7405-ENG-48
• OSTI ID: 587023
• Report Number(s): CONF-9704102--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 403; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CURRENT DENSITY
ICR HEATING
NEUTRAL ATOM BEAM INJECTION
NON-INDUCTIVE CURRENT DRIVE
PLASMA HEATING
PLASMA PRESSURE
RF SYSTEMS
TOKAMAK DEVICES