Sawtooth stabilization by electron cyclotron heating at the q =1 surface in the WT-3 tokamak

Journal Article · Thu Aug 01 04:00:00 EDT 1991 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.859636· OSTI ID:5587168

Tanaka, S; Hanada, K; Tanaka, H; Iida, M; Ide, S; Minami, T; Nakamura, M; Maekawa, T; Terumichi, Y ^[1]; Yamada, M; Manickam, J; White, R B ^[2]

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1. Department of Physics, Faculty of Science, Kyoto University, Kyoto 606, Japan (JP)
2. Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (USA)

Sawtooth oscillations (STO) in the Ohmically heated (OH) WT-3 tokamak ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research} 1988 (IAEA, Vienna, 1989), Vol. 1, p. 563) are strongly modified or suppressed by localized electron cyclotron resonance heating (ECH) near the {ital q}=1 surface, where {ital q} refers to the safety factor. The effect of ECH is much stronger when it is applied on the high-field side, as compared to the low-field side. Complete suppression of the STO is achieved for the duration of the ECH when it is applied on the high-field side, in a low-density plasma, provided the ECH power exceeds a threshold value. This threshold decreases with the increasing safety factor at the limiter {ital q}{sub {ital L}} and the complete stabilization of STO can be obtained even when ECH is applied on the low-field side in the high-{ital q}{sub {ital L}} region. It is noticeable that these complete stabilizations can be obtained only by the localized ECH with the elliptic antenna. The STO stabilization is attributed to a modification of the current density profile by high-energy electrons generated by ECH, which reduces the shear in the {ital q}=1 region.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 5587168
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 3:8; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
CLOSED PLASMA DEVICES
ECR HEATING
ELECTRIC HEATING
HEATING
HIGH-FREQUENCY HEATING
INHIBITION
JOULE HEATING
MODIFICATIONS
OSCILLATIONS
PLASMA
PLASMA HEATING
RESISTANCE HEATING
SAWTOOTH OSCILLATIONS
STABILIZATION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
WT-3 TOKAMAK