High-beta discharges in the DIII-D tokamak

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859543· OSTI ID:7036643

Ferron, J R; Chu, M S; Helton, F J; Howl, W; Kellman, A G; Lao, L L; Lazarus, E A; Lee, J K; Osborne, T H; Strait, E J; Taylor, T S; Turnbull, A D ^[1]

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1. General Atomics, San Diego, California 92138 (USA)

Low-{ital q} ({ital q}{sub 95}{lt}3) double-null divertor discharges with values of the volume-average toroidal beta as high as 9.3% have been operated in the DIII-D tokamak (Fusion Technol. {bold 8}, 441 (1985)). In discharges with {ital q}{sub 95}{approx}5, values of {beta}{sub {ital T}}/({ital I}/{ital aB}) as high as 5 have been obtained. These discharges are shown to be at or below the stability limit to the value of beta for infinite-{ital n}, ideal ballooning modes. The discharges are significantly below the beta limit for ideal,low toroidal mode number kink modes. The kink mode beta limit is shown to be strongly dependent on the radial profiles of plasma pressure and current. The theoretical beta limit in DIII-D is shown to be in the range {beta}{sub {ital T}}/({ital I}/{ital aB})=4 --5 depending on the value of {ital I}/{ital aB}, and this is consistent with the experiment. High-beta discharges have been operated with ion temperature up to 17 keV. Steady-state, high-beta, low-{ital q} operation is demonstrated by a discharge with {ital I}/{ital aB}=2.6, {ital q}{sub 95}=2.7, in which {beta}{sub {ital T}}{gt}7% is maintained for 1.5 sec.

• DOE Contract Number: AC03-89ER51114
• OSTI ID: 7036643
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Journal Issue: 6 Vol. 2:6; 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
700107 -- Fusion Energy-- Plasma Research-- Instabilities
ANNULAR SPACE
BALLOONING INSTABILITY
BEAM INJECTION
CLOSED CONFIGURATIONS
CLOSED PLASMA DEVICES
CONFIGURATION
DEUTERIUM
ELECTRIC DISCHARGES
ENERGY RANGE
HIGH-BETA PLASMA
HYDROGEN ISOTOPES
INSTABILITY
ION TEMPERATURE
ISOTOPES
KEV RANGE
KEV RANGE 10-100
KINK INSTABILITY
LIGHT NUCLEI
MAGNETIC FIELD CONFIGURATIONS
NEUTRAL ATOM BEAM INJECTION
NUCLEI
ODD-ODD NUCLEI
OPERATION
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SCALING LAWS
SPACE
STABLE ISOTOPES
STEADY-STATE CONDITIONS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION