Dissipation mechanism in 3D magnetic reconnection
Dissipation mechanism in 3D magnetic reconnection
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DOI：
10.1063/1.3642609
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发表时间：
2011-10
影响因子：
2.2
通讯作者：
K. Fujimoto
中科院分区：
文献类型：
--
作者：
K. Fujimoto
利用三维电磁粒子模拟方法研究了无碰撞等离子体中快速磁场重联的耗散过程。本研究重新访问了在先前研究中进行的两次模拟运行（Fujimoto，Phys. Plasmas 16，042103（2009））;一次在电流密度方向上具有较小的系统尺寸，另一次具有较大的系统尺寸。当系统尺寸较小时，重联过程与二维重联过程基本相同，而当系统尺寸较大时，电流片结构发生剧烈变形，并出现沿着电流密度演化的扭结模式.虽然在这两种情况下都实现了快速重联，但它们之间的耗散机制非常不同。在没有扭折模的情况下，电子在没有热化的情况下通过电子扩散区，因此磁耗散仅由惯性电阻率支持。另一方面，在扭折电流片中，电子不仅在布居中加速，而且在布居中加速。
Dissipation processes responsible for fast magnetic reconnection in collisionless plasmas are investigated using 3D electromagnetic particle-in-cell simulations. The present study revisits the two simulation runs performed in the previous study (Fujimoto, Phys. Plasmas 16, 042103 (2009)); one with small system size in the current density direction, and the other with larger system size. In the case with small system size, the reconnection processes are almost the same as those in 2D reconnection, while in the other case a kink mode evolves along the current density and deforms the current sheet structure drastically. Although fast reconnection is achieved in both the cases, the dissipation mechanism is very different between them. In the case without kink mode, the electrons transit the electron diffusion region without thermalization, so that the magnetic dissipation is supported by the inertia resistivity alone. On the other hand, in the kinked current sheet, the electrons are not only accelerated in bu...