空间等离子体中波粒相互作用的混合模拟研究

There commonly exist the kinetic processes in waves-particle interactions in space plasmas. During CME's propagation, the interactions between fast moving plasmoid and background solar wind are also mainly effected by wave-particle interaction. Our investigation shows that the ion temperature in solar wind increases if the difference of their speeds is sufficiently greater than Alfven speed. This mechanism is very useful for the research of accelerating and heating in solar wind. We also use two dimensional and three components hybrid simulation to study magnetic field reconnection, and the results show that a few ions are accelerated to very high energy, and the spherical shell of particle velocity distribution will be formed by variety kinds of accelerated particles. About 70% of ions escape along the magnetic field lines rapidly. If the pressure is anisotropic, the instability growth rate sufficiently increases and the reconnection is speeded up when perpendicular magnetic pressure is greater than parallel pressure; contrariously the fire hose instability appears and the tearing mode instability and reconnection process are restrained.

波粒相互作用是空间物理的基本过程之一，仔细研究其物理机制，是了解许多与该过程有关的宏观现象的关系。在众多波粒相互作用现象中，我们着重研究新生离子拾起加速和激波对离子的加速两方面内容。结合卫星观测和理论模型，用混合模拟的方法研究这些微观过程的变化和规律，进一步应用这些研究结果，对太阳高能离子的产生等宏观问题作出解释。