宇宙线福布什下降的数值模拟

本文从银河宇宙线的太阳调制方程出发,认为激波对宇宙线的影响是由一扰动区产生的。在此扰动区中太阳风速度增加,扩散系数下降。由此进行了数值模拟,模拟结果表明:扩散系数的下降在产生福布什下降时要比太阳风速度的增加更为有效;福布什下降在近日球层内向外传播时,其幅度随径向距离的增大而衰减;两个无相互作用的激波同时存在时所产生的福布什下降为每个激波单独存在时的福布什下降的简单线性迭加。 

NUMERICAL SIMULATION OF THE COSMIC RAY FORBUSH DECREASE

Considering that the effect of shock waves on cosmic ray is simply produced by a disturbed region where the solar wind speed is raised and the diffusion coefficient is reduced. The numerical modeling on the base of solar modulation of galactic cosmic ray is performed. It is found that the decrease of diffusion coefficient is more effective than the increase of solar wind speed in producing the Forbush clecrease.The amplitude of Forbush decrease is getting smaller as it propagates outward. The Forbush decrease when two independent shock waves exist is simply the linear superposition of the two Forbush decreases produced as if the two shock waves exist separately.