摘要
从稀薄气体动力学理论出发,设计了直接模拟分子流真空系统内三维压力分布的事件触发式实验粒子蒙特卡洛方法。在算法设计中,不考虑分子间碰撞,以分子与固壁的碰撞为迭代触发点,模拟分子运动过程并通过统计分子与压力统计面的碰撞频率从而计算系统内的三维真空压力分布。详细介绍了算法思路和程序流程、放气率与泵抽速的数值离散过程,以及三维压力分布的统计方法。采用该程序模拟圆管两侧的压差与通过气体流量的关系,直接计算圆管流导并与克努森修正公式进行对比,验证了该方法模拟管道流导的误差小于4%。最后模拟了光阴极电子枪内的三维真空压力分布,分析了其内部复杂结构对真空压力分布的影响。
The 3-D pressure distribution in molecular flow vacuum system was simulated in event-triggering Test Particle Monte Carlo （TPMC） method, based on rarefied gas dynamics. In the simulation, since only molecule- wall collision is considered in molecular flow, the spatial pressure profile can be statistically derived in terms of the molecule-wall collision frequency involved. The discussions with specific example focused on the simulation algorithm, numerical discretization of outgassing rate and pumping speed, and statistical derivation of spatial pressure distribution. The molecular flow through a cylindrical tube was theoretically evaluated with Knudsen formula and numerically simulated with the lab-developed program based on event-triggering TPMC method, and the discrepancy was found to be less than 4%. In addition, the pressure profile in the photoelectron gun with complicated structure was tentatively investigated in a thought provoking way.
作者
刘佰奇
马永胜
郭迪舟
何平
Liu Baiqi;Ma Yongsheng;Guo Dizhou;He Ping(Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China)
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2018年第5期363-368,共6页
Chinese Journal of Vacuum Science and Technology
基金
中国科学院高能物理研究所谢家麟基金项目
