【作者】 吕建红；

【导师】 胡希伟；

【作者基本信息】 华中科技大学 ， 脉冲功率与等离子体， 2007， 硕士

【摘要】 等离子体激波面中存在很强的密度和温度梯度,且此极端梯度使激波面中的电子流速和离子流速产生差别,从而造成电荷分离产生强电场。这种激波面中的强电场和参量梯度单独或共同驱动静态激波面上的不同于以往电中性给出的流体不稳定模式（如瑞利-泰勒不稳定性）的新型的静电不稳定模式。本文从等离子体的双流体方程和泊松方程出发,分别从高频(ω≥ω_pe)和低频(ω≤ω_pi)两个不同频段讨论了一维平面激波波前中这种新型的静电不稳定性。得到:1)、在高频情况下,不稳定模由电场或（和）参量梯度驱动,且得到的不稳定波的频率的实部类似于电子静电波,增长率在波矢平行激波方向（k=k_xe_x）要大垂直（k=k_ye_y）方向两个量级。2)、在低频情况下,不稳定模也是由电场或（和）参量梯度驱动,且得到的不稳定波的频率的实部类似于离子静电波,增长率在平行和垂直方向大小在同一量级。另外,我们还得到了一支绝对不稳定模。同时,在两种情况下我们均给出了频率的实部和增长率与平衡量(n_e0（x）,u_e0（x）,T_e0（x） ,E₀（x）)的关系。更多还原

【Abstract】 In a plasma shock front, there are extremely high density and temperature gradients. So, the particle and heat diffusive fluxes caused by the density and temperature gradients are very large and the corresponding difference between the electron and ion diffusive fluxes will produce large charge separation （strong electrostatic field） in front. The one of the effects of this electrostatic field on the non-neutral shock is that it-self or it together with the parameter gradients can drive several instabilities on the equilibrium （steady state） shock front. These instabilities are a kind of new electrostatic modes, which are qualitatively different from those well known neutral modes （e.g. Rayliegh-Taylor or Richtmyer-Meshkov instability） driven only by the parameters gradient in the neutral shock front or discontinuity.These new mentioned instabilities are investigated in this text with high frequency (ω≥ω_pe) and low frequency (ω≤ω_pi) respectively in a plane （one dimensional） plasma shock front by double fluid equations and Poisson equation. It can be concluded that: 1) In the case of high frequency, the instabilities are driven by the electrostatic field or /and parameter gradients, and the real parts of instabilities are similar to the one of electron electrostatic （plasma） wave, the growth rate in paralleling direction is about two magnitudes larger than in the perpendicular direction. 2) In the case of low frequency, the instabilities are also driven by the electrostatic field or/and parameter gradients, and the real parts of instabilities are similar to the one of ion electrostatic （plasma） wave, the growth rate in paralleling direction is in the same magnitude as the growth rate in the perpendicular direction. But more we find that there exit an absolute unstable mode—zero-frequency instability mode. This text we also give the dependencies of real frequencies and growth rates on the steady profiles of n_e0（x）,u_e0（x）,T_e0（x） and E₀（x） in both cases.更多还原