NONRELATIVISTIC PARALLEL SHOCKS IN UNMAGNETIZED AND WEAKLY MAGNETIZED PLASMAS
NONRELATIVISTIC PARALLEL SHOCKS IN UNMAGNETIZED AND WEAKLY MAGNETIZED PLASMAS
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DOI：
10.1088/0004-637x/759/1/73
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
J. Niemiec;M. Pohl;A. Bret;Volkmar Wieland
中科院分区：
文献类型：
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作者：
J. Niemiec;M. Pohl;A. Bret;Volkmar Wieland
我们给出了非相对论等离子体与无或平行大尺度磁场碰撞的2D3V粒子胞内模拟结果，以获得适用于年轻超新星遗迹条件的参数。我们研究了不同密度的等离子体板的碰撞，导致了两个不同的冲击和一个接触不连续。电子动力学在该系统的发展中起着重要的作用。虽然非磁化和磁化等离子体中的非相对论激波都可以由魏贝尔型不稳定性来调节，但当存在大尺度磁场时，激波形成过程的效率更高。正向和反向激波下游的电子分布通常是各向同性的，而离子的情况并不总是这样。我们没有看到任何重要的前加速证据，无论是在电子布居中还是在离子分布中。
We present results of 2D3V particle-in-cell simulations of nonrelativistic plasma collisions with absent or parallel large-scale magnetic field for parameters applicable to the conditions at young supernova remnants. We study the collision of plasma slabs of different density, leading to two different shocks and a contact discontinuity. Electron dynamics play an important role in the development of the system. While nonrelativistic shocks in both unmagnetized and magnetized plasmas can be mediated by Weibel-type instabilities, the efficiency of shock-formation processes is higher when a large-scale magnetic field is present. The electron distributions downstream of the forward and reverse shocks are generally isotropic, whereas that is not always the case for the ions. We do not see any significant evidence of pre-acceleration, neither in the electron population nor in the ion distribution.