Distributions of alpha particles escaping to the wall during sawtooth oscillations in the Tokamak Fusion Test Reactor
- Scientific Centre Institute for Nuclear Research, Kyiv, 252650 (Ukraine)
- Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)
- Scientific Centre Institute of Nuclear Research, Kyiv, 252650 (Ukraine)
It has been observed experimentally in deuterium{endash}tritium shots of the Tokamak Fusion Test Reactor (TFTR) [D. J. Grove and D. M. Meade, Nucl. Fusion {bold 25}, 1167 (1985)] that crashes of sawtooth oscillations may result in very inhomogeneous flux of alpha particles to the wall. To explain this phenomenon, both theoretical analysis and numerical simulation have been carried out. It is concluded that the {open_quotes}crash-induced prompt loss,{close_quotes} i.e., the orbital loss of marginally trapped particles arising because of the crash-induced orbit transformation of circulating particles, is responsible for the flux near the bottom of the vessel, whereas the crash-induced stochastic diffusion of moderately trapped particles explains the large signal near the equatorial plane of the torus. The calculated poloidal distributions of the integral alpha flux are in reasonable agreement with experimental data. The energy spectrum of the escaping particles has also been calculated, which can be used for diagnostics of the crash type. {copyright} {ital 1999 American Institute of Physics.} thinsp
- OSTI ID:
- 335591
- Journal Information:
- Physics of Plasmas, Vol. 6, Issue 4; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
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