Wall stabilization of high beta plasmas in DIII-D

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871262· OSTI ID:63689

Taylor, T S; Strait, E J; Lao, L L; Mauel, M; Turnbull, A D; Burrell, K H; Chu, M S; Ferron, J R; Groebner, R J; La Haye, R J; Rice, B W; Snider, R T; Thompson, S J; Wroblewski, D; Lightly, D J ^[1]

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1. General Atomics, P.O. Box 85608, San Diego, California 92186-9784 (United States)

Detailed analysis of recent high beta discharges in the DIII-D [{ital Plasma} {ital Physics} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research}, 1986 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] tokamak demonstrates that the resistive vacuum vessel can provide stabilization of low {ital n} magnetohydrodynamic (MHD) modes. The experimental beta values reaching up to {beta}{sub {ital T}}=12.6% are more than 30% larger than the maximum stable beta calculated with no wall stabilization. Plasma rotation is essential for stabilization. When the plasma rotation slows sufficiently, unstable modes with the characteristics of the predicted ``resistive wall`` mode are observed. Through slowing of the plasma rotation between the {ital q}=2 and {ital q}=3 surfaces with the application of a nonaxisymmetric field, it has been determined that the rotation at the outer rational surfaces is most important, and that the critical rotation frequency is of the order of {Omega}/2{pi}=1 kHz.

• Research Organization: General Atomics
• DOE Contract Number: AC03-89ER51114; AC05-84OR21400; W-7405-ENG-48
• OSTI ID: 63689
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DOUBLET-3 DEVICE
HIGH-BETA PLASMA
MAGNETOHYDRODYNAMICS
ROTATING PLASMA
STABILITY
TOKAMAK DEVICES
WALL EFFECTS