Modified two-stream instability at perpendicular collisionless shocks: Full particle simulations
Modified two-stream instability at perpendicular collisionless shocks: Full particle simulations
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修正垂直无碰撞冲击下的两流不稳定性：完整粒子模拟
DOI：
10.1029/2011ja017182
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and R. Yamazaki
中科院分区：
文献类型：
--
作者：
T. Umeda;Y. Kidani;S. Matsukiyo;and R. Yamazaki
对自洽激发的垂直无碰撞激波中产生的微观不稳定性进行了全粒子模拟研究。当前具有高离子-电子质量比的二维模拟表明，修正的双流不稳定性可以通过入射和反射离子与在准垂直于环境磁场的方向上传播的电磁哨声模式波的相互作用来产生。激发哨声波的性质与基于模拟速度分布函数的线性色散分析一致。研究还发现，激发波在激波法线方向有一个电子尺度的波长，在激波切向方向有一个离子尺度的波长，这表明电子尺度的微扰和离子尺度的激波结构通过修正的双流不稳定性相互耦合。
A full particle simulation study is carried out for studying microinstabilities generated in self‐consistently excited perpendicular collisionless shocks. The present two‐dimensional simulation with a high ion‐to‐electron mass ratio shows that the modified two‐stream instability can be generated by the interaction of incoming and reflected ions with electromagnetic whistler mode waves propagating in the direction quasi‐perpendicular to the ambient magnetic field. Properties of the excited whistler mode waves are consistent with the linear dispersion analysis based on the simulated velocity distribution functions. It is also found that the excited waves have an electron‐scale wavelength in the shock‐normal direction and an ion‐scale wavelength in the shock‐tangential direction, suggesting that the electron‐scale microturbulences and the ion‐scale shock structures are coupled with each other through the modified two‐stream instability.