Coalescence of magnetic islands including anomalous resistivity
Coalescence of magnetic islands including anomalous resistivity
复制标题
磁岛的合并，包括反常电阻率
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
B. Kliem
中科院分区：
文献类型：
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作者：
J. Schumacher;B. Kliem
提出了低β等离子体中聚结不稳定性的二维可压缩磁流体动力学模拟，其中允许出现反常电阻率。在均匀电流片配置中考虑不稳定性，最初受到反常电阻率点的无限链的扰动。从基于 Fadeev 平衡的模拟中得知的不稳定性的两个阶段（理想阶段和电阻阶段）在此配置中也可以清楚地区分。研究发现，磁能转化为动能主导欧姆加热。主要的能量释放发生在几个阿尔文渡越时间内。将聚结岛之间形成的当前层中的几个关键参数的比例与通过均匀电阻率获得的比例进行比较。数值结果表明，当 S−α α=15–13 时，峰值重连率向大 Lundquist 数 (S≫104) 减小，并且在 S≳107 时可能会发生向慢速重连 (α∼12) 的转变，w...
Two-dimensional compressible magnetohydrodynamic simulations of the coalescence instability in a low-beta plasma are presented in which anomalous resistivity is permitted to occur. The instability is considered in a uniform current sheet configuration, initially perturbed by an infinite chain of spots of anomalous resistivity. The two phases of the instability known from simulations based on the Fadeev equilibrium—ideal and resistive—can clearly be distinguished also in this configuration. It is found that the conversion of magnetic energy into kinetic energy dominates Ohmic heating. The main energy release occurs within a few Alfven transit times. The scaling of several key parameters in the current layer formed between the coalescing islands is compared to the scalings obtained with uniform resistivity. The numerical results indicate that the peak reconnection rate decreases toward large Lundquist numbers (S≫104) as S−α with α=15–13 and that a transition to slow reconnection (α∼12) may occur at S≳107, w...