H mode in the TUMAN-3 tokamak triggered by edge plasma perturbations

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860726· OSTI ID:6424194

Askinazi, L G; Golant, V E; Lebedev, S V; Levin, L S ^[1]; Rozhansky, V A ^[2]; Tendler, M ^[3]

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1. A. F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)
2. State Technical University of St. Petersburg, St. Petersburg 195251 (Russian Federation)
3. Alfven Laboratory, Royal Institute of Technology, Stockholm 10044 (Sweden)

Several types of edge plasma perturbations in the TUMAN-3 tokamak [[ital Proceedings] [ital of] [ital the] 13[ital th] [ital International] [ital Atomic] [ital Energy] [ital Agency] [ital Conference] [ital on] [ital Plasma] [ital Physics] [ital and] [ital Controlled] [ital Nuclear] [ital Fusion] [ital Research], 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 1, p. 509] have been demonstrated to trigger the Ohmic H-mode transition. It is shown that three different methods, (1) radial electric field of either sign imposed by an electrode biased up to 500 V, (2) perturbation of the edge plasma density by strong gas puffing, and (3) LiD pellet injection, bring about the Ohmic H mode. In biasing experiments, the degree of improvement of particle and energy confinement depends on the polarity of the electric field and is higher for negative biasing. The evaporation of a LiD pellet ([ital V][similar to]150 m/sec, size [similar to]0.3 mm, density perturbation[similar to]50%) in the peripheral region of the plasma column can also lead to the H-mode transition. Experimental results are shown to be in reasonable agreement with the theory of radial electric fields in tokamaks.

• OSTI ID: 6424194
• Journal Information: Physics of Fluids B; (United States), Vol. 5:7; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
TOKAMAK DEVICES
PLASMA CONFINEMENT
TRANSPORT
ELECTRIC FIELDS
LITHIUM DEUTERIDES
PELLET INJECTION
PLASMA DENSITY
POLARIZATION
ALKALI METAL COMPOUNDS
CLOSED PLASMA DEVICES
CONFINEMENT
DEUTERIDES
DEUTERIUM COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
LITHIUM COMPOUNDS
LITHIUM HYDRIDES
THERMONUCLEAR DEVICES
700310* - Plasma Confinement- (1992-)
700330 - Plasma Kinetics
Transport
& Impurities- (1992-)