论文标题
由二维电阻扭结不稳定驱动的磁重新连接和浆液形成
Magnetic reconnection and plasmoid formation driven by the two-dimensional resistive kink instability in a current hole configuration
论文作者
论文摘要
我们在二维（2D）构型中研究了$ M = 1 $电阻的内部扭结模式的非线性演变，该构型包含负电流密度的中心区域，也称为“电流孔”设置。有限元代码FinMHD用于求解具有电流涡流配方的简化不可压缩的磁性流动力（MHD）方程。首先，扭结不稳定性与电阻内部扭结模式的一般理论一致，随后导致当前纸的形成。在相对较低的lundquist数字$ s $下，磁重新连接过程以甜蜜派制度预测的利率进行。相反，当$ s $超过$ s_c \ simeq 10^4 $的临界值时，当前表被稍微以下的alfvénic时间尺度形成的浆液形成所破坏。在后一种情况下，达到了富含浆液的petshek型特征的随机重新连接方案。还测量了相对快速的归一化重新连接率$ 0.02 $。最后，我们将我们的结果与使用理想的MHD不稳定性启动该过程的相似2D研究中获得的结果进行了比较，并讨论了它们与等离子链形成的一般理论以及相关的快速重新连接制度的相关性。
We investigate the nonlinear evolution of the $m = 1$ resistive internal kink mode in a two-dimensional (2D) configuration containing a central region of negative current density, also known as the "current hole" setup. The finite-element code FINMHD is used to solve a reduced set of incompressible Magnetohydrodynamic (MHD) equations with a current-vorticity formulation. First, the kink instability linearly develops in agreement with the general theory of resistive internal kink mode, and it subsequently leads to the formation of a current sheet. At relatively low Lundquist number $S$, a magnetic reconnection process proceeds with a rate predicted by the Sweet-Parker regime. Conversely, when $S$ exceeds a critical value that is $S_c \simeq 10^4$, the current sheet is disrupted by the formation of plasmoids on a slightly sub-Alfvénic time scale. In the latter case, a stochastic reconnection regime exhibiting Petshek-type features enriched by plasmoids is reached. A relatively fast normalized reconnection rate value of order $0.02$ is also measured. Finally, we compare our results with those obtained in similar 2D previous studies using ideal MHD instabilities to initiate the process, and discuss their relevance for the general theory of plasmoid chains formation and associated fast reconnection regime.
