无束流条件下钼栅极电击穿特性的试验研究  

Experimental Study on Electric Breakdown Characteristics of Molybdenum Grids without Beam

作　　者：雷伟 杨福全[1] 郭德洲 LEI Wei;YANG Fuquan;GUO Dezhou(Science and Technology on Vacuum Technology and Physics Laboratory,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,兰州730000

出　　处：《真空与低温》2020年第4期323-327,共5页Vacuum and Cryogenics

基　　金：民用航天预研项目(D010509)。

摘　　要：离子推力器栅极间较小的间距、较高的工作电压,使其具备了高比冲、高效率的优点,但也导致其在正常工作时,容易在工作条件变化的情况下发生打火放电,引起工作不稳定和不可靠。因此,研究离子推力器栅极打火放电的影响因素及其关系是十分必要的。论文在无束流引出的状态下,对离子推力器钼栅极的高压击穿特性进行了研究。结果表明,当压力低于1×10^-2Pa,栅间距为0.7 mm且栅极表面无损伤时,击穿电压和击穿电场随真空度降低而减小;栅间距为0.4 mm且栅极表面有损伤时,击穿电压和击穿电场随压力增大而先增大,后减小。当压力大于1×10^-2Pa,两种栅间距下,击穿电压和击穿电场均随压力增大而减小,下降速度均比低压力下快。The ion thruster has the advantages of high specific impulse and high efficiency due to its small grids spacing and high working voltage,but it is also prone to spark discharge under the condition of changing working conditions during normal operation,resulting in unstable and unreliable operation. Therefore,it is necessary to study the influencing factors and their relations of grids ignition discharge of ion thruster. In this paper,the high voltage breakdown characteristics of molybdenum grids in ion thruster are studied under the condition of no beam. The results show that when the vacuum degree is higher than 1×10-2 Pa,the grids spacing is 0.7 mm and the grids surface is not damaged,the breakdown voltage and the breakdown electric field decrease with the decrease of the vacuum degree;when the grids spacing is 0.4 mm and the grids surface is damaged,the breakdown voltage and breakdown electric field first increase and then decrease with the decrease of vacuum degree. When the vacuum degree is lower than 1×10-2 Pa,the breakdown voltage and the breakdown electric field decrease with the decrease of the vacuum degree,and the decline rates are faster than that under high vacuum.

关 键 词：钼栅极 栅间距 真空度 真空击穿 

分 类 号：V439[航空宇航科学与技术—航空宇航推进理论与工程]