Bowers K, Li H
Plasma Physics (X-1), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2007 Jan 19;98(3):035002. doi: 10.1103/PhysRevLett.98.035002.
We investigate the magnetic energy transfer from the fluid to kinetic scales and dissipation processes using three-dimensional fully kinetic particle-in-cell plasma simulations. The nonlinear evolution of a sheet pinch is studied where we show that it exhibits both fluid scale global relaxation and kinetic scale collisionless reconnection at multiple resonant surfaces. The interactions among collisionless tearing modes destroy the original flux surfaces and produce stochastic fields, along with generating sheets and filaments of intensified currents. In addition, the magnetic energy is transferred from the original shear length scale both to the large scales due to the global relaxation and to the smaller, kinetic scales for dissipation. The dissipation is dominated by the thermal or pressure effect in the generalized Ohm's law, and electrons are preferentially accelerated.
我们使用三维全动力学粒子模拟研究了从流体尺度到动力学尺度的磁能转移以及耗散过程。研究了片状箍缩的非线性演化，结果表明它在多个共振面处既表现出流体尺度的全局弛豫，又表现出动力学尺度的无碰撞重联。无碰撞撕裂模之间的相互作用破坏了原有的通量面并产生随机场，同时产生增强电流的片状结构和细丝。此外，磁能由于全局弛豫从原有的剪切长度尺度转移到更大尺度，同时也转移到更小的动力学尺度用于耗散。耗散由广义欧姆定律中的热效应或压力效应主导，并且电子被优先加速。
