存在初始引导场情况下的无碰撞磁场重联

采用二维三分量的全粒子模拟方法研究了不同初始引导场情况下的无碰撞磁场重联及初态为一维的Harris电流片.结果表明,Bz0＞0.5B0的强引导场不仅会显著改变粒子的运动轨迹,而且会改变重联区附近的电场和流场结构,从而影响重联率和电子加速.运用广义欧姆定律解释了不同引导场下电场的结构特征.另外,通过对扩散区附近束流电子的跟踪研究发现,在二维模型中,不论引导场强弱,位于扩散区中心垂直模拟平面的感应电场对电子加速起主要作用,而扩散区外平面电场的贡献很小. 

Collisionless Magnetic Reconnection in Presence of a Guide Field

This paper studies the coUisionless magnetic reconnection in the presence of different guide fields using two-and-a-half dimensional full particle simulation. The results show that, a strong guide field with Bz0 〉 0.5B0 will not only strongly alter the motion of electrons but also change the structure of electric field and velocity field around the reconnection region, thus affect the reconnection rate and electron accelerating process. General Ohm＇s law for two-fluid MHD model is employed to explain the characteristics of these electric field structures. And by tracing beams of electrons near the diffusion region, it is found that in the 2D model, electric field component perpendicular to the simulation plane and located at the center of diffusion region plays the major role in the electron acceleration, while the other two components contribute very little, no matter the guild field is strong or not.