Relativistic particle dynamics in a steepening magnetosonic wave
Relativistic particle dynamics in a steepening magnetosonic wave
复制标题
陡峭磁声波中的相对论粒子动力学
DOI：
10.1063/1.859021
复制
发表时间：
1989
期刊：
影响因子：
--
通讯作者：
J. Dawson
中科院分区：
文献类型：
--
作者：
B. Lembége;J. Dawson
用数值模拟的方法研究了大振幅磁声波对电子和离子的加速。非线性效应形成的饱和机制，并限制振幅低于粒子物种可以进行无限的加速，这是理论上预期的水平。尖峰结构出现在密度和场的波形，是相对论制度的特点。Elx×Bz漂移场和Ety场对电子和离子都有很强的加速作用，但它们的共振特性随场的变化有很大的不同。在捕获时间附近，相对论性电子类孤波从主波斜坡触发;提出了一些解释它们的机制。电子和离子都被强烈地加热，但损失了波能。这种阻尼与大的空间电荷效应所造成的尖刺结构的起源是一些观察到的场能量饱和水平。
Acceleration of both electrons and ions to relativistic energy by large amplitude magnetosonic waves is investigated by use of numerical simulation. Nonlinear effects are shown to form the saturation mechanism and limit the amplitude below the level where a particle specie can undergo unlimited acceleration, which is expected theoretically. Spiky structures appear both in density and field waveforms that are characteristics of the relativistic regime. Both electrons and ions are strongly accelerated by Elx×Bz drift and Ety field, but their resonance features versus fields are strongly different. Around the trapping time, relativistic electron solitonlike wavelets are triggered from the main wave ramp; a few mechanisms are proposed for their interpretation. Both electrons and ions are strongly heated at the expense of the wave energy. This damping in association with the large space charge effects resulting from the spiky structures is the origin of some observed saturation level in the field energy.