LIPS-200离子推力器电子反流极限不确定度分析  

Uncertainty Analysis in LIPS-200 Electron Backstreaming Limit

作　　者：张雪儿 孟伟[1] 李得天[1] ZHANG Xueer;MENG Wei;LI Detian(Science and Technology on Vacuum Technology and Physics Laboratory,Key Laboratory of Space Electric Propulsion Technology of Gansu Province,Lanzhou Institute of Physics,Lanzhou 730000,China)

机构地区：[1]兰州空间技术物理研究所真空技术与物理重点实验室甘肃省空间电推进技术重点实验室,兰州730000

出　　处：《真空与低温》2022年第1期66-71,共6页Vacuum and Cryogenics

基　　金：民用航天“十三五”技术预先研究项目(D010509)。

摘　　要：针对延长离子推力器栅极极限寿命的恒定加速电压和步进调节加速电压两种优化方法的工程应用需求,结合现有LIPS-200离子推力器产品技术参数,基于电子反流极限的Williams解析表达并应用QMU工程方法,定量计算了LIPS-200离子推力器电子反流极限的不确定度。计算结果表明:不确定度主要影响因素包括束流电子温度、加速栅孔初始直径、加速栅孔内聚焦束流的分布直径及电流大小、加速栅厚度、栅间距和束流电势的不确定度等。目前离子推力器电子反流极限不确定度最大为17.6 V、常规为7.4 V;通过采取降低主要影响参数不确定度的控制措施,电子反流极限不确定度可减小到最大为13.0 V、常规为5.1 V;若电子反流极限不确定度从15 V降低到10 V,离子推力器的优化极限寿命可延长570~885 h。To apply the constant-accel-potential and stepping-accel-potential methods for extending the lifetime of gridded ion thruster,the uncertainty in the electron backstreaming limit(V_(EBS))of LIPS-200 is quantified based on QMU and WGW methods.The results show that this uncertainty arises from the uncertainty in each of the correlated parameters,which include plume electron temperature,accel grid aperture size,beamlet diameter,beamlet current,accel grid thick‐ness,grid gap,and plume plasma potential.Currently,the best estimation and upper bound of the uncertainty in VEBS are 7.4 V and 17.6 V,respectively.Through an uncertainty control on main parameters,these values can be reduced to 5.1 V and 13.0 V,respectively.By reducing the uncertainty in V_(EBS) from 15 V to 10 V,the optimized thruster lifetime can in‐crease by 570~885 h.

关 键 词：电子反流极限 不确定度 极限寿命 离子推力器 优化方法 

分 类 号：V439.1[航空宇航科学与技术—航空宇航推进理论与工程]