Collisionless plasma expansion into vacuum: Two new twists on an old problem
Collisionless plasma expansion into vacuum: Two new twists on an old problem
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无碰撞等离子体膨胀到真空：老问题的两个新转折
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
B. Breizman
中科院分区：
文献类型：
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作者：
A. Arefiev;B. Breizman
本文讨论了由热电子和冷离子组成的无碰撞等离子体向真空膨胀的一般问题。膨胀是由电子压力引起的，并作为从电子到离子的能量传递机制。这个过程通常是在麦克斯韦电子的假设下描述的，它在没有碰撞的情况下很容易失效。本文讨论了两种自然存在的非麦克斯韦分布系统：膨胀的激光辐照纳米等离子体和从磁喷嘴出来的超音速射流。所提出的严格的动力学描述证明了偏离麦克斯韦分布如何从根本上改变等离子体膨胀过程中的离子加速过程。这一结果指出了在无碰撞等离子体膨胀问题中完全动力学处理的重要性。
The paper deals with a generic problem of collisionless plasma expansion into vacuum in the regimes where the expanding plasma consists of hot electrons and cold ions. The expansion is caused by electron pressure and serves as an energy transfer mechanism from electrons to ions. This process is often described under the assumption of Maxwellian electrons, which easily fails in the absence of collisions. The paper discusses two systems with a naturally occurring non-Maxwellian distribution: an expanding laser-irradiated nanoplasma and a supersonic jet coming out of a magnetic nozzle. The presented rigorous kinetic description demonstrates how the deviation from the Maxwellian distribution fundamentally alters the process of ion acceleration during plasma expansion. This result points to the critical importance of a fully kinetic treatment in problems with collisionless plasma expansion.