无碰撞磁场重联中的不同电子特征:不同质量比下的PIC模拟

Different Signatures of Electron in Collisionless Magnetic Reconnection:PIC Simulation with Different Mass Ratio

采用二维三分量的全粒子模拟方法研究了不同离子电子质量比(mi/me)下的无碰撞磁场重联中的电子特征.研究结果显示:质量比(mi/me)几乎对重联率没有影响,但是对扩散区的电子行为却影响很大.随着质量比的增大,沿着分离线的电子出流区变窄,从而电子的出流速度增大.在较大的质量比事例中出现了平行于磁场的电场,这些电场对电子的加速和加热有着重要的影响.

A two-and-a-half dimensional electromagnetic particle-in cell（PIC） simulation code is used to investigate electron behaviour in collisionless magnetic reconnection. The results show that the mass ratio （mi/me） almost has no impact on the reconnection rate, however it can significantly affect electron behaviour in the diffusion region. For the case with larger mass ratio, the width of electron outflow region along the separatrix is thinner, and hence the peak of the electron outflow speed is essentially larger. The parallel electric field E// along the separatrix can be found in the case with larger mass ratio, which may have significant influences on the acceleration.