负氢离子源中电子能量沉积三维数值模拟研究

3D simulation of the electron energy distribution in negative hydrogen ion source

本文理论计算了多峰离子源永磁体,采用二体碰撞模型(binary collision)处理电子之间的库仑碰撞,采用空碰撞(null-collision)方法处理电子与氢元素相关粒子,开发了全三维PIC-MCC模拟算法,并利用该算法模拟了多峰离子源中电子沉积过程,分析了多峰磁场对电子的空间和能量分布影响,结果显示:电子的非均匀分布起源于高能电子在引出区的B×▽B漂移.

In this paper,we calculate permanent magnet theoretically for a multicusp ion source Coulomb collision between electrons is treated with the ＂binary collision＂ model and collisions between the electrons and hydrogen species are treated with the ＂null-collision＂ method.A 3D PIC-MCC simulation algorithm is developed,and based on this algorithm the electron deposition process in multicusp ion source is simulated,and the multicusp magnetic field effects on the electron energy distribution and spatial distribution are analyzed. The results show that the spatial non-uniformity of electron distribution comes from high energy electron B×▽B drift in the filter field.