Abstract:
Abstract： Unexpected electrical breakdown of the ion thruster directly affects the reliability of its engineering application. Based on the relatively complete data of breakdown events in the ground life test, a preliminary study was conducted on the breakdown phenomenon of LIPS-200 ion thruster in its 12000h life test with analysis approaches including data comparison, Weibull statistics and causal inference. Quantitative results were obtained, such as the average breakdown rate, the time distribution of breakdown events, the Weibull distribution of classified breakdown intervals. Analysis shows that the average breakdown rate of LIPS-200 is much lower than that of NSTAR and other products mainly because of its lower electrical field between grids; the distribution of breakdown events has a noticeable dependence on cumulative operating time; the characteristic breakdown intervals and breakdown rate change caused by different factors and mechanisms can be obtained with 2-parameter Weibull distribution model.

Key words: statistical analysis, Weibull model, unexpected electrical breakdown, ion thruster, data comparison