High Frequency Shear Alfvén Instability driven by Circulating Energetic Ions in NSTX
Authors: Ya. I. Kolesnichenko, R.B. White, and Yu.V. Yakovenko
It is shown that a number of features of an instability with the frequency comparable to the ion gyrofrequency observed in the National Spherical Torus Experiment (E.D. Fredrickson, et al., Report P5.058 at the 33rd EPS Conference on Plasma Physics, Rome, 2006) are consistent with the features of the Alfvén instability with large, about the inverse Larmor radius of the energetic ions (ρβ-1) longitudinal wave numbers. The conclusions drawn are based on an analysis of the resonant interaction of the energetic circulating ions and the waves, as well as on the calculation of the instability growth rate taking into account effects of the finite Larmor radius, ρβ.
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Published in: Physics of Plasmas 13, 122503 (2006) 3 pp
doi: 10.1063/1.2402129
Copyright (2006) American Institute of Physics.
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