无碰撞等离子体电流片中的低频波

采用两种无碰撞二维三分量不可压缩磁流体力学（MHD）模型，计入电子扰动压力张量效应，研究了电流片等离子体的色散性质和波.由于得到的一般色散关系较为复杂，只解析讨论了电流片的中心区和电子β*e=0两种特殊情况.主要结果如下：(1)在短波区（kdi＞1），存在快磁声 动理学Alfven波和斜Alfven 哨声模，电子磁流体力学模型是足够精确的MHD模型；在长波区（kdi＜1＝，存在Alfven波和离子声波，理想的MHD模型是适用的.（2）电子β*e＝0情况下的结果，显然遗漏了一些波模（如离子声波和快磁声动理关键词：电流片磁流体力学电子压力张量色散关系

Low-frequency waves in collisionless plasma current sheet

Linear dispersion properties and waves of collisionless plasma current sheet at small scales are discussed, using 25dimensional, collisionless and incompressible magnetohydrodynamic (MHD) models with the full electron pressure tensor. General dispersion relations are very complex. Two special cases, i.e., the central region of current sheet and the electronβ*e=0, are analytically studied here. The main results are as follows. (1) In the ion inertial region (kdi>1), there are fast magnetosonic-kinetic Alfven waves and obliquely Alfven-whistler waves, and the electron magnetohydrodynamic (EMHD) model is a precise MHD model. In the long wavelength region (kdi<1), there are Alfven waves and ion acoustic waves, and the ideal MHD model is valid. (2) When electron β*e=0, the results drop off some modes, e.g., the fast magnetosonic-kinetic Alfven wave and ion acoustic wave. This case is not exactly valid for the current sheet plasma. (3) At central region of current sheet, results from both of physical models have fast magnetosonic kinetic Alfven waves.