Shock Heating of Directly Transmitted Ions
Shock Heating of Directly Transmitted Ions
复制标题
直接传输离子的冲击加热
DOI：
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发表时间：
2021
影响因子：
4.9
通讯作者：
M. Gedalin
中科院分区：
文献类型：
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作者：
M. Gedalin
无碰撞冲击非常有效地加热离子。离子加热是非绝热过程，下游温度与上游温度不成比例。激波跃迁后的离子分布与陀螺相相关，并逐渐陀螺化。随着马赫数的增加，反射离子对离子加热的贡献逐渐增大。然而，直接传递的离子可能仍然是造成大部分下游温度的原因。直接传输允许在窄冲击的近似范围内进行分析处理。确定了磁跃迁后的陀螺相位相关分布和激波后更远的陀螺向性分布，并建立了磁压缩与最大超调磁场的关系。
Collisionless shock heats ions very efficiently. Ion heating is a nonadiabatic process and the downstream temperature is not proportional to the upstream temperature. Ion distributions just behind the shock transition are gyrophase dependent and gradually gyrotropize. With the increase of the Mach number the contribution of reflected ions into ion heating gradually increases. Yet, directly transmitted ions may remain responsible for most of the downstream temperature. Direct transmission allows analytical treatment within the approximation of a narrow shock. We determine the gyrophase-dependent distribution just behind the magnetic jump, the gyrotropic distribution farther behind the shock, and establish the relation with the magnetic compression and the maximum overshoot magnetic field.