Excitation of kinetic Alfve´n waves by resonant mode conversion and longitudinal heating of magnetized plasmas
作者:
Motohiko Tanaka,
Tetsuya Sato,
A. Hasegawa,
期刊:
Physics of Fluids B: Plasma Physics
(AIP Available online 1989)
卷期:
Volume 1,
issue 2
页码: 325-332
ISSN:0899-8221
年代: 1989
DOI:10.1063/1.859145
出版商: AIP
数据来源: AIP
摘要:
Simulation of the kinetic Alfve´n wave is performed using a two‐and‐one‐half‐dimensional (2 (1)/(2) ‐D) macroscale particle [magnetohydrodynamic (MHD) scale kinetic] simulation code. An oscillating antenna current is applied in one of the boundary regions to launch MHD perturbations into an inhomogeneous plasma in which a sheared magnetic field is present. It is shown that the applied perturbation is mode converted into the kinetic Alfve´n wave at the Alfve´n resonance layers, resulting in resonant heating of both the ions and electrons. When the plasma beta is relatively low, only the electrons are heated along the ambient magnetic field. The electron heating rate is found to be scaled asdTe∥/dt∝&bgr;1/2e〈&dgr;B2y〉, where &bgr;eis the electron beta and 〈&dgr;B2y〉 is the wave magnetic field intensity. In contrast, ion heating occurs when the ion beta is close to unity and the temperature ratio satisfiesTe/Ti>1. Besides plasma heating, it is found that the plasma particles are accelerated along the ambient magnetic field in the direction of the wave propagation through Landau resonance with the kinetic Alfve´n wave.
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