Guide field dependence of 3-D X-line spreading during collisionless magnetic reconnection
Guide field dependence of 3-D X-line spreading during collisionless magnetic reconnection
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DOI：
10.1029/2012ja017867
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发表时间：
2012-08
影响因子：
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通讯作者：
L. Shepherd;P. Cassak
中科院分区：
文献类型：
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作者：
L. Shepherd;P. Cassak
[1]理论论证和大规模的双流体模拟被用来研究扩散的重联X线定位在电流的方向作为一个函数的平面外（引导）磁场的强度。结果表明，弱导场和强导场引起扩散的机制是不同的。在弱引导场限制下，扩散是由于载流子的运动，如先前已经建立的。然而，对于强引导场的扩展是双向的，并且是由于阿尔芬波沿着引导场的激发。在一般情况下，我们认为，X线传播的双向速度由两个机制中的较快的每个方向。预测的指导领域的强度，其中的传播机制的变化制定和验证与三维模拟。太阳，磁层，和实验室的应用进行了讨论。
[1] Theoretical arguments and large-scale two-fluid simulations are used to study the spreading of reconnection X-lines localized in the direction of the current as a function of the strength of the out-of-plane (guide) magnetic field. It is found that the mechanism causing the spreading is different for weak and strong guide fields. In the weak guide field limit, spreading is due to the motion of the current carriers, as has been previously established. However, spreading for strong guide fields is bidirectional and is due to the excitation of Alfven waves along the guide field. In general, we suggest that the X-line spreads bidirectionally with a speed governed by the faster of the two mechanisms for each direction. A prediction on the strength of the guide field at which the spreading mechanism changes is formulated and verified with three-dimensional simulations. Solar, magnetospheric, and laboratory applications are discussed.