Energetic-Ion-Driven Toroidal Alfv{acute e}n Eigenmodes Observed in a Heliotron/Torsatron Plasma

Journal Article · Thu Jul 01 00:00:00 EDT 1999 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.83.312· OSTI ID:355458

Takechi, M; Takagi, S; Matsunaga, G; Ohkuni, K; Shimizu, M ^[1]; Toi, K; Ohdachi, S; Akiyama, R; Fujisawa, A; Gotoh, M; Idei, H; Iguchi, H; Isobe, M; Kojima, M; Kubo, S; Lee, S; Minami, T; Morita, S; Matsuoka, K; Nishimura, S ; Okamura, S; Osakabe, M; Sasao, M; Takahashi, C; Tanaka, K; Yoshimura, Y ^[2]; Darrow, D S ^[3]; Kondo, T ^[4]

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1. Department of Energy Engineering Science, Nagoya University, Nagoya 464-8601 (Japan)
2. National Institute for Fusion Science, Toki 509-5292 (Japan)
3. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
4. Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292 (Japan)

Toroidal Alfv{acute e}n eigenmodes (TAEs) of low toroidal mode number, n=1 and 2, are observed in neutral-beam-heated plasmas in the compact helical system heliotron/torsatron. The observed frequency is proportional to the computed TAE frequency and lies near the lower bound of the innermost TAE gap. The modes are excited only when the beam velocity exceeds about half the central Alfv{acute e}n velocity and when the net plasma current induced by coinjected neutral beams is in the required range. The modes are localized in the plasma core region, between 0.2 and 0.6 of the plasma minor radius. {copyright} {ital 1999} {ital The American Physical Society }

• OSTI ID: 355458
• Journal Information: Physical Review Letters, Vol. 83, Issue 2; Other Information: PBD: Jul 1999
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
HYDROGEN
THERMONUCLEAR REACTORS
ALFVEN WAVES
TOROIDAL CONFIGURATION
TORSATRON STELLARATORS
HELIOTRON
BEAM-PLASMA SYSTEMS