Strong ion acceleration by a collisionless magnetosonic shock wave propagating perpendicularly to a magnetic field
Strong ion acceleration by a collisionless magnetosonic shock wave propagating perpendicularly to a magnetic field
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垂直于磁场传播的无碰撞磁声冲击波产生强离子加速
DOI：
10.1063/1.865394
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发表时间：
1985
影响因子：
4.6
通讯作者：
Y. Ohsawa
中科院分区：
文献类型：
--
作者：
Y. Ohsawa
用2 1/2维、全相对论、全电磁粒子程序研究了沿垂直于磁场方向传播的非线性磁声脉冲的时间演化。脉冲由活塞瞬时加速激发，并以完全自洽的方式演化。一个大幅度的脉冲捕获一些离子，并使它们平行于波前加速。当它们的速度变为E×B漂移速度和波相速度之和的数量级时，它们被脱禁，其中E是波传播方向的电场。在无碰撞的等离子体中，由于共振离子加速引起的耗散，脉冲发展成为准冲击波。冷等离子体的一个简单的非线性波动理论描述了在模拟中观察到的激波特性，但不包括共振离子的影响。特别地，对激波区域的电势大小进行了解析推导，并发现其具有很好的稳定性。
A 2 1/2 ‐dimension, fully relativistic, fully electromagnetic particle code is used to study the time evolution of a nonlinear magnetosonic pulse propagating in a direction perpendicular to a magnetic field. The pulse is excited by an instantaneous piston acceleration, and evolves in a totally self‐consistent manner. A large amplitude pulse traps some ions and accelerates them parallel to the wave front. They are detrapped when their velocities become of the order of the sum of the E×B drift velocity and the wave phase velocity, where E is the electric field in the direction of the wave propagation. The pulse develops into a quasishock wave in a collisionless plasma because of dissipation caused by the resonant ion acceleration. A simple nonlinear wave theory for a cold plasma describes the shock properties observed in the simulation except for the effects of resonant ions. In particular, the magnitude of an electric potential across the shock region is derived analytically and is found to be in good agre...