Suppression of reflected electrons by kinetic Alfven turbulence in a quasi-perpendicular shock: Particle-in-cell simulations
Suppression of reflected electrons by kinetic Alfven turbulence in a quasi-perpendicular shock: Particle-in-cell simulations
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准垂直激波中运动阿尔文湍流对反射电子的抑制：细胞内粒子模拟
DOI：
10.1088/0004-637x/736/1/35
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Saito and T. Umeda
中科院分区：
文献类型：
--
作者：
Ishida;N.;S. Saito and T. Umeda
激波漂移加速度是准垂直无碰撞激波中与磁镜沿磁场反射有关的电子加速度的重要机制之一。研究了面内磁场中波纹激波面对电子磁镜像反射的影响。仿真结果表明，波纹激波面产生后，反射电子数减少。在激波过渡区产生的波动的电波数谱和磁波数谱表明动力学alfv<s:1>湍流的存在。动力学alfv录影带湍流通过平行散射减小了电子的俯仰角，从而减小了作用在电子上的磁镜力。这些结果表明，激波产生的动力学alfv<s:1>湍流在激波漂移加速过程中抑制了电子的磁镜反射。
Shock drift acceleration is one of the important mechanisms for electron acceleration associated with magnetic mirror reflection along the magnetic field in a quasi-perpendicular collisionless shock. We study the influence of a rippled shock surface in the in-plane magnetic field on the magnetic mirror reflection of electrons. Simulation results show that the number of reflected electrons reduces after generation of the rippled shock surface. Electric and magnetic wavenumber spectra of the generated fluctuations in the shock transition region indicate the existence of kinetic Alfvén turbulence. The kinetic Alfvén turbulence decreases the electron pitch angle by parallel scattering, which reduces the magnetic mirror force acting on the electrons. These results suggest that the shock-generated kinetic Alfvén turbulence suppresses the magnetic mirror reflection of electrons during the shock drift acceleration.