Electron heating by ion acoustic turbulence in simulated low Mach number shocks
Electron heating by ion acoustic turbulence in simulated low Mach number shocks
复制标题
模拟低马赫数冲击中离子声湍流的电子加热
DOI：
10.1063/1.866095
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发表时间：
1987
影响因子：
4.6
通讯作者：
K. Quest
中科院分区：
文献类型：
--
作者：
Robert L. Tokar;S. Gary;K. Quest
使用代码波在一维和二维空间中对垂直、无碰撞和标称亚临界冲击进行了显式和完全电磁粒子模拟[Phys. Fluids 14，830（1971）]。冲击参数的选择，以最大限度地提高增长率的电流驱动的离子声不稳定性的冲击。在冲击波中观察到离子声湍流对电子的加热，其速率与二阶弗拉索夫理论预测一致。然而，电阻电子加热的量很小，离子反射提供了耗散的主要来源。严格的电阻冲击对于适合于在今天的超级计算机上运行的显式粒子代码的参数来说是不存在的，因为等离子体通过这些冲击的对流如此之快，以至于电流驱动的不稳定性几乎没有时间被放大并加热电子。这种效应主要是由于可以分析的ωpe/ωce值相对较小。
Explicit and fully electromagnetic particle‐in‐cell simulations of perpendicular, collisionless, and nominally subcritical shocks are performed in one and two spatial dimensions using the code wave [Phys. Fluids 14, 830 (1971)]. Shock parameters are chosen to maximize the growth rates of the current driven ion acoustic instability in the shock. Electron heating by ion acoustic turbulence is observed at the shocks, at rates in agreement with second‐order Vlasov theory predictions. However, the amount of resistive electron heating is small and ion reflection provides the major source of dissipation. Strictly resistive shocks do not exist for the parameters suitable for explicit particle codes running on today’s supercomputers, because the plasma convects through these shocks so quickly that current driven instabilities have little time to be amplified and to heat the electrons resistively. This effect is primarily a result of the relatively small values of ωpe/ωce that can be analyzed.