Effect of flow damping on drift-tearing magnetic islands in tokamak plasmas
- Department of Physics, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
A systematic fluid theory of nonlinear drift-tearing magnetic island dynamics in a conventional large aspect-ratio low-{beta} circular cross-section tokamak plasma is derived from a set of single-helicity reduced neoclassical-magnetohydrodynamical equations which incorporate electron and ion diamagnetic flows, ion gyroviscosity, poloidal and toroidal flow damping, cross flux-surface momentum and particle transport, the sound wave, and the drift wave. The equations neglect the compressible Alfven wave, electron inertia, the electron viscosity tensor, magnetic field-line curvature, and finite ion orbit widths. A collisional closure is used for plasma dynamics parallel to the magnetic field. The influence of various different levels of flow damping on the phase velocity of an isolated island, as well as the ion polarization term appearing in its Rutherford equation, are investigated in detail. Furthermore, it is found that, under certain circumstances, a locked island is subject to destabilizing ion polarization term to which a comparable isolated (i.e., rotating) island is not.
- OSTI ID:
- 21277312
- Journal Information:
- Physics of Plasmas, Vol. 16, Issue 7; Other Information: DOI: 10.1063/1.3191719; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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