Destabilization of tokamak pressure-gradient driven instabilities by energetic alpha-particle populations

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Fusion Technology; (United States)

OSTI ID:6099066

Spong, D A; Holmes, J A; LeBoeuf, J N; Christenson, D J ^[1]

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1. Oak Ridge National Lab., TN (United States)

This paper reports on alpha-particle populations that can significantly alter existing magnetohydrodynamic (MHD) instabilities in tokamaks through kinetic effects and coupling to otherwise stable shear Alfven waves. Resonances of the trapped alpha-particle precessional drift, with the usual ballooning mode diamagnetic frequency ({omega}{sub *i}/2) and the toroidicity-induced Alfven eigenmode (TAE), are considered. These are examined for noncircular tokamaks in the high-n ballooning limit using an isotopic alpha-particle slowing down distribution and retaining the full-energy and pitch-angle dispersion in the alpha-particle drift frequency. Applying this to the Compact Ignition Tokamak (CIT) and the International Thermonuclear Experimental Reactor (ITER) indicates that ballooning instabilities can persist at betas below the ideal MHD threshold. These are especially dominated by the destabilization of the TAE mode. In addition, a hybrid fluid-particle approach for simulating alpha-particle effects on pressure-gradient driven instabilities is described.

• OSTI ID: 6099066
• Journal Information: Fusion Technology; (United States), Journal Name: Fusion Technology; (United States) Vol. 18; ISSN 0748-1896; ISSN FUSTE
• Country of Publication: United States
• Language: English

Related Subjects

665510 -- Magnetohydrodynamics-- (1992-)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330 -- Plasma Kinetics
Transport
& Impurities-- (1992-)
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALFVEN WAVES
ALPHA PARTICLES
BALLOONING INSTABILITY
CHARGED PARTICLES
CLOSED PLASMA DEVICES
COMPACT IGNITION TOKAMAK
FLUID MECHANICS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
INSTABILITY
ITER TOKAMAK
KINETICS
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PRESSURE GRADIENTS
REACTOR KINETICS
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS