Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA.
Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
Phys Rev E. 2017 Oct;96(4-1):043203. doi: 10.1103/PhysRevE.96.043203. Epub 2017 Oct 6.
Recent theory has demonstrated a novel physics regime for magnetic reconnection in high-energy-density plasmas where the magnetic field is advected by heat flux via the Nernst effect. Here we elucidate the physics of the electron dissipation layer in this regime. Through fully kinetic simulation and a generalized Ohm's law derived from first principles, we show that momentum transport due to a nonlocal effect, the heat-flux-viscosity, provides the dissipation mechanism for magnetic reconnection. Scaling analysis, and simulations show that the reconnection process comprises a magnetic field compression stage and quasisteady reconnection stage, and the characteristic width of the current sheet in this regime is several electron mean-free paths. These results show the important interplay between nonlocal transport effects and generation of anisotropic components to the distribution function.
最近的理论研究表明，在高能密度等离子体中，磁场通过纳诺斯特效应由热通量平流输运，这为磁重联开辟了一个新的物理领域。本文阐明了该物理领域中电子耗散层的物理特性。通过全动力学模拟和基于第一性原理推导出的广义欧姆定律，我们发现非局域效应（热通量粘性）导致的动量输运为磁重联提供了耗散机制。标度分析和模拟表明，重联过程包括磁场压缩阶段和准稳态重联阶段，在该物理领域中，电流片的特征宽度约为几个电子平均自由程。这些结果表明了非局域输运效应与各向异性分布函数分量产生之间的重要相互作用。
