Mechanism of ion acceleration at perpendicular collisionless shocks
垂直无碰撞激波的离子加速机制

With one-dimensional(1D)perpendicular collisionless shocks obtained by full particle simulation,the mechanisms of shock acceleration of various initial energetic particles are investigated by using test particle method.The results show that the ions can be separated into two groups at the shock front:the reflected ions and the directly transmitted ions.Only the reflected ions can be accelerated significantly.Moreover,the lower initial energy ions are accelerated by shock surfing mechanism,and the higher initial energy ions gain energy by shock drift acceleration.Meanwhile,the thickness of the shock can significantly affect the acceleration process of ions.