Theory and Simulation of Nonlinear Phenomena in Laboratory and Astrophysical Plasmas

1.宇宙等离子体中的磁重联我们用二维粒子格子程序研究了等离子体对无力组态中的无碰撞磁重联过程。我们发现了一个非常有效的能量转换过程，其中大约50%的磁场能量可以转化为等离子体加热。激光-等离子体相互作用我们用二维和三维粒子格子程序研究了相对论电子束在等离子体中回流的驰豫过程。我们发现，系统变得不稳定，不稳定，导致许多小尺度的电流丝的形成。在小尺度细丝连续合并的非线性阶段，离子加速很强。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，日冕环足点是局部受热的。通过提出几种可能的新机制，我们研究了日冕环足点的形成机制。

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.