The effect of cavity density on the formation of electrostatic shock in the lunar wake: 1-D hybrid simulation  

作　　者：Yuan Jin Ye Pang 

机构地区：[1]Institute of Space Science and Technology,Nanchang University,Nanchang 330031,China [2]School of Information Engineering,Nanchang University,Nanchang 330031,China

出　　处：《Earth and Planetary Physics》2020年第3期223-230,共8页地球与行星物理（英文版）

基　　金：the National Natural Science Foundation of China(NSFC)under grant 41664007。

摘　　要：One-dimensional hybrid simulations are carried out to study the plasma refilling process in the lunar wake.Previous theoretical and simulation studies have shown that ion-ion acoustic(ⅡA)instability can be initiated and electrostatic shock can be formed under the condition Te>>Ti.We find that the time evolution ofⅡA instability and the formation of electrostatic shock strongly depend on initial cavity density.The initial position of the electrostatic shock is dependent on the ratio between initial cavity density and background solar wind density,i.e.,the farther away the initial position,the lower is the ratio.When the initial cavity density is low enough,the density and electric field profile across the wake become much complex.Meanwhile,the back-to-back electrostatic shock is unstable in the case of lower cavity densities;at the late evolution stage,a new shock-like structure can be formed at the central region of the lunar wake.

关 键 词：plasma refilling ion-ion acoustic instability Moon wake electrostatic shock 

分 类 号：P184[天文地球—天文学]