随机磁场对静电波驱动的速度扩散的影响

随机磁场改变了波与粒子之间的耦合关系。因而使波驱动的速度扩散受到影响。其结果是:波电场的横向分量可以对纵向速度扩散有贡献;∈<<1情形,扩散系数的共振峰被展宽;∈>>1情形,扩散系数的振荡效应被削弱。当随机磁场的关联时间与波的特征时间之间相对大小不同时,随机磁场产生影响的具体机制不完全相同,所造成的后果也有差别。对于接近于在垂直方向传播的波,随机磁场对速度扩散的影响一般是重要的。

THE EFFECTS OF STOCHASTIC MAGNETIC FIELD ON THE VELOCITY DIFFUSION DRIVEN BY ELECTROSTATIC WAVES

The stochastic magnetic field modifies the interaction of the waves with the electrons, and the wave-driven velocity diffusion may be effected. However, the mechanisms and the results are not all the same, if the value of correlation time of the stochastic magnetic field is different. In general, due to the effects of stochastic magnetic field, the transverse component of the electric field of waves can contribute to the longitudinal velocity diffusion, the resonant peaks of diffusion coefficient in the case of ∈<< 1 are extended, and, in the case of ∈>>1 , the oscillating effects of diffusion coefficient are weakened. For the waves propagating nearly perpendicular to the magnetic field the effects of stochastic magnetic field on the velocity diffusion driven by the waves may be important.