Life prediction of ion thruster based on sputtering erosion failure of accelerator grid

A crucial failure mode restricting the life of ion thruster lies in the sputtering erosion of accelerator grid. For the characteristics of long life and multi-power working, a corresponding model was used to predict the life of ion thruster based on the accelerator grid pit and groove erosion data. Firstly, by analyzing the change law between accelerator grid groove depth and operating time under various power segments, it was found that the operating power sequence had little influence on the erosion rate of groove. And then the fatigue accumulation damage was introduced to establish the life prediction model for ion thruster operating under multi-power segments. At last, the life prediction model was used to predict the life of NASA's Evolutionary Xenon Thruster (NEXT). The predicted result of 46 041 h coincides with the test well.