Particle description of the electron diffusion region in collisionless magnetic reconnection
Particle description of the electron diffusion region in collisionless magnetic reconnection
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DOI：
10.1063/1.3263694
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发表时间：
2009-11
影响因子：
2.2
通讯作者：
K. Fujimoto;R. Sydora
中科院分区：
文献类型：
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作者：
K. Fujimoto;R. Sydora
本文从粒子动力学的角度阐明了二维系统中无碰撞磁场重联的耗散机制。电子在电子扩散区域中被加速而没有热化，进行曲折振荡，并且被喷射离开X线。这种电子行为不仅产生了基于粒子描述的电子惯性电阻率，而且它可以是电子粘性的起源，导致在X线附近的广义欧姆定律中的非对角压力张量项。我们推导出的电子压力张量项的分析配置文件，并确认该配置文件是一致的粒子在细胞模拟。结果表明，流体中电子粘性引起的磁耗散与粒子描述中的惯性电阻率引起的磁耗散是等价的。并提出电子电流片的宽度与电子线的宽度相当。
The present study clarifies the dissipation mechanism of collisionless magnetic reconnection in two-dimensional system based on particle dynamics. The electrons are accelerated without thermalization in the electron diffusion region, carry out the meandering oscillation, and are ejected away from the X-line. This electron behavior not only generates the electron inertia resistivity based on the particle description, but also it can be the origin of the electron viscosity resulting in the off-diagonal pressure tensor term in the generalized Ohm’s law near the X-line. We derive an analytical profile for the electron pressure tensor term and confirm that the profile is consistent with the particle-in-cell simulation. The present results demonstrate that the magnetic dissipation due to the electron viscosity in the fluid picture is equivalent to that due to the inertia resistivity in the particle description. It is also suggested that the width of the electron current sheet is on the order of the electron ine...