| Full text | |
| Author(s): |
Elfimov, A. G.
Total Authors: 1
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| Document type: | Journal article |
| Source: | Physics of Plasmas; v. 25, n. 6 JUN 2018. |
| Web of Science Citations: | 1 |
| Abstract | |
The effect of a minor concentration of energetic particles produced by ion cyclotron resonance (ICR) heating on the stability of Geodesic Acoustic Modes (GAM) is studied using fully drift kinetic equation. Assuming the ICR layer position on the high field side of the tokamak magnetic axis, a minority ion distribution is modeled by the energetic ion tail and ``triangle{''}-like pitch angle distribution with the maximum at the trapped-passing ion boundary. The resulting GAM instability is found when the hot ion thermal velocity is larger than the effective parallel GAM phase velocity Rq omega and the geodesic frequency has the order of the energetic ion bounce frequency. The standard GAM frequency may be strongly reduced by some small concentration of the energetic ions allowing the mode to be unstable. Respective neoclassical polarization corrections (residual flow) driven by energetic ions are found to be negative and larger than that calculated by Rosenbluth and Hinton {[}Phys. Rev. Lett. 80, 724 (1998)]. Qualitative comparison of the theory with ICR heating experiments in tokamak is discussed. Published by AIP Publishing. (AU) | |
| FAPESP's process: | 11/50773-0 - Center of excellence in physics and applications of plasmas |
| Grantee: | Ricardo Magnus Osório Galvão |
| Support Opportunities: | Research Projects - Thematic Grants |