Destabilization of Tokamak Pressure-Gradient Driven Instabilities by Energetic Alpha-Particle Populations
| Autor: | Peggy Jo Christenson, Jean-n. Leboeuf, Donald A. Spong, Jeffrey A Holmes |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Physics
Tokamak Thermonuclear fusion 020209 energy General Engineering 02 engineering and technology Mechanics 01 natural sciences Instability Ballooning 010305 fluids & plasmas law.invention Physics::Plasma Physics law Normal mode 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Magnetohydrodynamic drive Magnetohydrodynamics Atomic physics Pressure gradient |
| Zdroj: | Fusion Technology. 18:496-504 |
| ISSN: | 0748-1896 |
| DOI: | 10.13182/fst90-a29285 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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