WHAT IS THE CONDITION FOR FAST MAGNETIC RECONNECTION
WHAT IS THE CONDITION FOR FAST MAGNETIC RECONNECTION
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DOI：
10.1086/187666
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发表时间：
1994-12-01
影响因子：
4.9
通讯作者：
SHIBATA, K
中科院分区：
文献类型：
--
作者：
YOKOYAMA, T;SHIBATA, K
磁浮力不稳定性驱动的磁重联研究使用二维MHD模拟两种电阻率模型：均匀电阻率，和异常电阻率。研究发现，重联率并不是由驱动过程唯一决定的，而是强烈依赖于电阻率模型，即，中性点附近的局部等离子体条件。均匀电阻率情况变为稳态Sweet-Parker型，异常电阻率情况趋于非稳态Petschek型。在后一种情况下，重联率随异常电阻率阈值的增大而增大。磁岛（等离子体团）的形成及其随后从电流片中喷出被发现是导致快速重联的关键物理过程。
The magnetic reconnection driven by magnetic buoyancy instability is studied using two-dimensional MHD simulations for two resistivity models; uniform resistivity, and anomalous resistivity. It is found that the reconnection rate is not uniquely determined by the driving process but strongly dependent on the resistivity model, i.e., the local plasma condition near the neutral point. The uniform resistivity case becomes steady Sweet-Parker type, while the anomalous resistivity case tends to nonsteady Petschek type. In the latter case, the reconnection rate increases with increasing threshold of anomalous resistivity. The formation of magnetic islands (plasmoids) and their subsequent ejection from the current sheet is found to be a key physical process leading to fast reconnection.