Particle Acceleration and Magnetic Dissipation in Relativistic Current Sheet of Pair Plasmas
Particle Acceleration and Magnetic Dissipation in Relativistic Current Sheet of Pair Plasmas
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DOI：
10.1086/522226
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发表时间：
2007-08
期刊：
影响因子：
--
通讯作者：
S. Zenitani;M. Hoshino
中科院分区：
文献类型：
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作者：
S. Zenitani;M. Hoshino
研究了具有反平行磁场的对（e±）等离子体的相对论性和超相对论性电流片的线性和非线性发展。本文采用粒子池模拟的方法研究了两类二维问题。首先，我们提出了相对论性磁重联的发展，其流出速度为光速c数量级。证明了粒子在重联区内和周围被强烈加速，并且大部分磁能转化为等离子体动能的“非热”部分。其次，我们提出了另一个二维问题，即横场平面上的电流片。在这种情况下，发生相对论漂移扭结不稳定性（RDKI）。粒子加速也会发生，但RDKI很快将磁能消散为等离子体热量。我们详细讨论了粒子加速的机理和RDKI理论。重要的是，只要我们考虑动力学，这两个过程的性质在T≤mc2的相对论范围内是相似的。两种过程的比较表明，在相对论性电流片中，RDKI的磁耗散过程更为有利。因此，RDKI应该重新考虑条纹脉冲星风的设想。
We study linear and nonlinear development of relativistic and ultrarelativistic current sheets of pair (e±) plasmas with antiparallel magnetic fields. Two types of two-dimensional problems are investigated by particle-in-cell simulations. First, we present the development of relativistic magnetic reconnection, whose outflow speed is on the order of the light speed c. It is demonstrated that particles are strongly accelerated in and around the reconnection region and that most of the magnetic energy is converted into a "nonthermal" part of plasma kinetic energy. Second, we present another two-dimensional problem of a current sheet in a cross field plane. In this case, the relativistic drift kink instability (RDKI) occurs. Particle acceleration also takes place, but the RDKI quickly dissipates the magnetic energy into plasma heat. We discuss the mechanism of particle acceleration and the theory of the RDKI in detail. It is important that properties of these two processes are similar in the relativistic regime of T ≳ mc2, as long as we consider the kinetics. Comparison of the two processes indicates that magnetic dissipation by the RDKI is a more favorable process in the relativistic current sheet. Therefore, the striped pulsar wind scenario should be reconsidered by the RDKI.