Theory and Simulation of Nonlinear Phenomena in Laboratory and Astrophysical Plasmas

1. 宇宙等离子体中的磁重联利用二维细胞内粒子编码研究了对等离子体无力构型中无碰撞磁重联的过程。我们发现了一个非常有效的能量转换过程，其中约50%的磁场能量可以转换为等离子体加热。激光与等离子体相互作用本文利用二维和三维的细胞内粒子编码研究了等离子体中具有回流的相对论电子束的弛豫过程。我们发现系统在形成不稳定时变得不稳定，导致许多小尺寸电流细丝的形成。在小尺度细丝连续聚并的非线性阶段，发生了强烈的离子加速。我们发现了强离子加速的物理机制。日冕环足点的机制最近的观测表明，日冕环足点是局部加热的。我们通过提出几种可能的新机制来研究日冕环足点的机制。

1. Magnetic Reconnection in Cosmic PlasmasWe investigated the process of collision-less magnetic reconnection in force-free configuration of pair plasmas by using 2-dimensional particle-in-cell code. We found a very effective energy converion process where about 50% of magnetic field energy can be converted to plasma heating.2. Laser-plasma InteractionWe investigated the relaxation process of relativistic electron beam with return current in plasma, by using 2- and 3-dimensional particle-in-cell code. We found that the system becomes unstable against fomentation instability, leading to formation of many small-scale current filaments. In the nonlinear stage of the successive coalescence of small-scale filaments there occurs strong ion acceleration. We found the physical mechanism of the strong ion acceleration.3. Mechanism of coronal loop footpointsRecent observations showed that the coronal loop footpoints are locally heated. We investigated the mechanism of the coronal loop footpoints by proposing several possible new mechanisms.