Numerical simulation study of particle momentum variation under acceleration at perpendicular shocks
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摘要：
利用测试粒子数值模拟的方法统计研究了电子在垂直激波附近每次穿越过程中的动量增量随粒子速度的变化规律.模拟采用的磁场模型是由均匀的背景磁场和slab+2D形式的三维湍流磁场叠加构成的.数值结果表明,粒子穿越激波面前后的相对动量变化和粒子动量的相对变化率均随速度的增加而减小,当速度大于2×10~8m/s时,粒子动量的相对变化率随速度呈现更加显著的衰减趋势,明显反映出相对论参数γ=1/■所引起的物理效应.模拟结果在较大的湍流强度范围内都与理论给出的变化关系较为一致.
Using test particle simulations,we have studied the change of electronparticle momentum increment during crossing the shock front with varying electronparticle velocity for electronacceleration at perpendicular shocks.We adopted a magnetic field model that is composed of a mean background field and a three-dimensional'slab+2D'turbulent field.The simulation results show that both the relative variation of particle momentum in the process of crossing shock front and the rate of particle momentum relative change decrease with increasing particle velocity.When the velocity is larger than 2×108m/s,the rate of particle momentum relative change displays a more noticeable decreasing tendency with particle velocity,which reflects the physical effect caused by the relativistic parameter r=1/■.Our simulation results agree,in a wide range of magnetic turbulence level,(b/B0)2=0.01-1.0,with the relationships given by the theorytheoretical results.
作者：
孔凡婧 秦刚
Kong Fanjing;Qin Gang(National Space Science Center,Chinese Academy of Science,Beijing 100190,China;College of Earth Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Science,Harbin Institute of Technology,Shenzhen 518055,China)
机构地区：
中国科学院国家空间科学中心 中国科学院大学地球科学学院 哈尔滨工业大学（深圳）理学院
出处：
《betway官方app 学报：自然科学版》 CAS 北大核心 2019年第3期9-14,共6页
基金：
国家自然科学基金(NNSFC 41574172)
关键词：
垂直激波 电子加速 动量变化 测试粒子模拟
perpendicular shock electron acceleration momentum variation test particle simulations
分类号：
P354 [天文地球—空间物理学]
