理论分析了负氢离子源中中性粒子传输特性及引出电极表面产生负氢离子(H-)的物理过程,研究了引出孔传输率对氢原子传输的影响,深入剖析了氢原子与不同属性导体壁碰撞以及碰撞后反射的物理情景.基于CHIPIC软件平台,成功研制了全三维Particle-in-cellwith Monte Carlo collision氢原子传输及负氢离子产生物理过程的模拟算法,并采用JAEA 10A负氢离子源进行模拟验证.模拟达到稳态后,氢原子平均能量约为0.57eV,且H原子呈现+Y漂移,当非均匀氢原子束轰击引出壁时,导致产生的负氢离子空间分布不均匀.这些模拟结果都与文献符合,验证了算法的可靠性.
The negative hydrogen ion source neutral particle transmission characteristics and the physical processes of the negative hydrogen ion extracted from plasma grid surface are analyzed. The influence of the extraction hole transfer rate which leads to hydrogen atom transmission is studied. A physical phenomenon of collision and reflection between H and different attribution conductor walls is explored. Then based on CHIPIC software platform, a full three-dimensional PIC-MCC simulation algorithm, in which the H transmission and the physical process of negative hydrogen ion production can be simulated, is successfully developed. It is verified by the simulation of JAEA 10A model. While the simulation reaches a steady state, the average energy of H is about 0.57 eV and H presents +Y drift. The non-uniform H beam bombarding the extraction wall leads to the spatial nonuniformity of negative hydrogen ions. These simulation results are consistent with those given in the literature, thereby verifying the reliability of the algorithm.