等离子体湍流对电子的加速

<span style="font-size: 13px; line-height: 19px">本文讨论了等离子体湍流对电子加速的两种模型:（1）假定在空间中存在一个空间均匀的等离子体湍流区,当具有一定初始分布的电子束通过此湍流区时,研究湍流场对电子束的加速过程;（2）在某一封闭的区域中,存在着具有一定初始分布和空间均匀的等离子体,当某种类型的等离子体波突然传入此等离子体区,然后考察此区中电子的加速过程。在这两种模型中,可能存在着某种电子消失机制。假定湍谱是幂指数形式,我们给出了不同类型湍流扩散系数的普遍形式。利用较简单的数学方法,求解了包括消失过程的一维准线性动力学方程,对于给定的初始分布,得出了分布函数的解析解,并给出了平均能量时间关系的表达式。另外,对于特定的湍谱指数,解出了当平行电场和湍流同时存在时的分布函数。最后,对所得结果进行了数值分析和讨论。</span>

<span style="font-size: 13px; line-height: 19px"> In this paper we discuss two acceleration models of electrons by the plasma turbulence: 1. A region of homogeneous plasma turbulence occurs on the high-latitude auroral field lines at altitudes ranging from 2000 km to 8000 km, when the electrons with determinate velocity distribution of the plasma sheet flows through this plasma turbulence region; these electrons can be accelerated by the plasma turbulence. This model can be used to discuss the acceleration of auroral electrons. 2. The homogeneous plasma with determinate velocity distribution exists in a closed region. When the plasma wave turbulence injects into this plasma region, the electrons can be accelerated by the plasma turbulence. The general form of turbulent diffusion coefficient is given assuming a power law spectral energy density. The quasilinear kinetic equation is solved by using simple mathematical method and the distribution function and mean energy of electrons are given for various cases.</span>