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Title: Numerical simulations of toroidal Alfven instabilities excited by trapped energetic ions

Abstract

Extensive magnetohydrodynamic-gyrokinetic hybrid simulations have been carried out to study the excitations of Alfven instabilities by trapped energetic ions in tokamak plasmas. Depending on the parameters, the most unstable mode can be either the toroidal Alfven eigenmode (TAE) or the energetic-particle mode (EPM). In both cases, the dominant instability driving mechanism is the resonance with the trapped-particle magnetic precessional drifts. The mode frequencies of the most unstable modes, meanwhile, tend to be near the toroidal frequency gap in order to minimize the continuum damping. It is also demonstrated that the instabilities can be quenched by reversing the magnetic precessional drifts via either negative magnetic shear or locating the magnetic turning points in the inner (strong B) side of the torus. (c) 2000 American Institute of Physics.

Authors:
 [1];  [1];  [2]
  1. Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697-4575 (United States)
  2. Naval Research Laboratory, Washington, DC 20375 (United States)
Publication Date:
OSTI Identifier:
20216542
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 7; Journal Issue: 6; Other Information: PBD: Jun 2000; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; PLASMA INSTABILITY; ALFVEN WAVES; PLASMA SIMULATION; NUMERICAL SOLUTION; TRAPPING; PLASMA CONFINEMENT; KINETIC EQUATIONS; THEORETICAL DATA

Citation Formats

Zheng, L.-J., Chen, Liu, and Santoro, R. A. Numerical simulations of toroidal Alfven instabilities excited by trapped energetic ions. United States: N. p., 2000. Web. doi:10.1063/1.874086.
Zheng, L.-J., Chen, Liu, & Santoro, R. A. Numerical simulations of toroidal Alfven instabilities excited by trapped energetic ions. United States. doi:10.1063/1.874086.
Zheng, L.-J., Chen, Liu, and Santoro, R. A. Thu . "Numerical simulations of toroidal Alfven instabilities excited by trapped energetic ions". United States. doi:10.1063/1.874086.
@article{osti_20216542,
title = {Numerical simulations of toroidal Alfven instabilities excited by trapped energetic ions},
author = {Zheng, L.-J. and Chen, Liu and Santoro, R. A.},
abstractNote = {Extensive magnetohydrodynamic-gyrokinetic hybrid simulations have been carried out to study the excitations of Alfven instabilities by trapped energetic ions in tokamak plasmas. Depending on the parameters, the most unstable mode can be either the toroidal Alfven eigenmode (TAE) or the energetic-particle mode (EPM). In both cases, the dominant instability driving mechanism is the resonance with the trapped-particle magnetic precessional drifts. The mode frequencies of the most unstable modes, meanwhile, tend to be near the toroidal frequency gap in order to minimize the continuum damping. It is also demonstrated that the instabilities can be quenched by reversing the magnetic precessional drifts via either negative magnetic shear or locating the magnetic turning points in the inner (strong B) side of the torus. (c) 2000 American Institute of Physics.},
doi = {10.1063/1.874086},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 6,
volume = 7,
place = {United States},
year = {2000},
month = {6}
}