Magnetohydrodynamic Vlasov simulation of the toroidal Alfvén eigenmode
Author(s) -
Y. Todo,
T. Sato,
Kunihiko Watanabe,
T. Watanabe,
R. Horiuchi
Publication year - 1995
Publication title -
physics of plasmas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.75
H-Index - 160
eISSN - 1089-7674
pISSN - 1070-664X
DOI - 10.1063/1.871235
Subject(s) - physics , magnetohydrodynamic drive , magnetohydrodynamics , amplitude , saturation (graph theory) , toroid , plasma , vlasov equation , normal mode , magnetic field , atomic physics , excitation , quantum electrodynamics , mechanics , quantum mechanics , mathematics , combinatorics , vibration
A new simulation method has been developed to investigate the excitation and saturation processes of toroidal Alfv?n eigenmodes (TAE modes). The background plasma is described by a magnetohydrodynamic (MHD) fluid model, while the kinetic evolution of energetic alpha particles is followed by the drift kinetic equation. The magnetic fluctuation of n=2 mode develops and saturates at the level of 1.8×10?3 of the equilibrium field when the initial beta of alpha particles is 2% at the magnetic axis. After saturation, the TAE mode amplitude shows an oscillatory behavior with a frequency corresponding to the bounce frequency of the alpha particles trapped by the TAE mode. The decrease of the power transfer rate from the alpha particles to the TAE mode, which is due to the trapped particle effect of a finite-amplitude wave, causes the saturation. From the linear growth rate the saturation level can be estimated
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