Comparison of toroidicity-induced Alfvén eigenmodes and energetic particle modes by gyrokinetic particle simulations

Journal Article · Wed May 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4803502· OSTI ID:22218610

Zhang, Chenxi; Li, Ding ^[1]; Zhang, Wenlu ^[1]; Lin, Zhihong ^[2]

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1. Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
2. Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

This work reports on linear global gyrokinetic particle simulations of the excitation of toroidicity-induced Alfvén eigenmodes (TAE) and energetic particle modes (EPM), and the comparison between these two modes. The TAE excitation by antenna clarifies the magnetohydrodynamic (MHD) mode structure and the discrete eigenmode exists in the gap between the upper and lower accumulation points. The TAE excitation by fast ions modifies the MHD mode structure because of radial symmetry breaking and the eigenmode frequency moves towards the lower accumulation point. The phase space structure of fast ions shows that both passing and trapped particles contribute to the TAE excitation and that trapped particles dominate the wave-particle resonance in our simulations. The growth rate of TAE is sensitive to the fast ion energy, density, and density gradient, which are also important factors contributing to the transition of the TAE to the EPM. The gyrokinetic particle simulations also confirm the excitation of EPM when the drive is stronger. The frequency of the EPM is determined by the characteristic frequencies of fast ion motion in toroidal geometry.

• OSTI ID: 22218610
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ANTENNAS
CHARGED-PARTICLE TRANSPORT
COMPARATIVE EVALUATIONS
ENERGY DENSITY
EXCITATION
IONS
MAGNETOHYDRODYNAMICS
PHASE SPACE
PLASMA
PLASMA DENSITY
PLASMA SIMULATION
SYMMETRY BREAKING
TRAPPING