低气压条件下氢气潘宁放电的模拟分析

为更好地理解低气压、弱电离条件下潘宁离子源放电过程中离子和电子的动力学行为, 通过建立二维轴对称模型, 采用粒子模拟与蒙特卡罗相结合(PIC/MCC)的方法, 考虑了电子与氢气之间的弹性碰撞、激发、电离以及氢原子、离子之间的弹性碰撞和电荷交换等过程, 对微型氢气潘宁离子源放电和引出过程进行了数值研究. 考察了磁场位形、壁面二次电子发射系数、引出电压和充气压力对放电过程的影响, 得到了实验中难以诊断得到的放电腔内电子与离子数密度分布, 阳极电流、引出极离子电流、单原子氢离子比例和双原子氢离子比例等宏观参数与实验结果相一致. 通过仿真使得对氢气潘宁放电机制的研究从定性过渡到定量, 这对于潘宁离子源的设计和改进具有重要意义. 关键词： 潘宁放电 氢气 粒子模拟 蒙特卡罗

Simulation study on hydrogen penning source discharge at low pressure

In order to better comprehend the dynamic behaviours of ion and electron during the Penning source discharge process under a low pressure and weak ionization condition, numerical simulation is carried out to study the penning source discharge and diffuse process. For constituting 2D axial symmetrical model and combining the particle simulation and Monte Carlo (PIC/MCC) method, elastic collision, excitation, and ionization reactions between electrons and hydrogen molecules, hydrogen atom and ions are taken into account. The effect of magnetic field configuration, secondary electron emission coefficient, derivational voltage, and gas pressure on the discharge characteristics is investigated. It has been found that the simulant discharge parameters, including electron and ion densities, anodic current and ionic current, H⁺ and H₂⁺ densities, etc, are in good agreement with the experimental results. Based on our numerical simulation, the study of the hydrogen penning discharge is being changed from qualitative analysis to quantitative calculation, which is important for the design and optimization of the penning ion source.
Keywords： penning discharge hydrogen particle simulation Monte Carlo