面向深空探测的30cm离子推力器寿命预估

为评价30cm离子推力器的寿命，提出了有限寿命考核结合栅极仿真模型的推力器寿命预估方法，利用粒子-蒙特卡洛（PIC-MCC）方法建立了栅孔溅射腐蚀模型，开展了30cm离子推力器寿命预估研究，分析了栅孔刻蚀速率、单孔电场及离子引出特性，给出了30cm推力器寿命预估值。结果表明，栅孔直径仿真与实测值一致性较好，误差在20%以内，基于每个寿命小节栅孔实测值对模型的修正是有效的；根据仿真结果，10000h寿命考核后，减速栅最先失效，30cm离子推力器在最大功率（3kW）工况下预估寿命为37540h，能够满足小天体探测任务对电推进系统的长寿命需求。

Life prediction of 30cm ion thruster for deep space exploration

In order to evaluate the lifetime of 30cm ion thruster，the thruster lifetime prediction method based on finite life test and simulation model was proposed.The grid hole sputtering erosion model was established by PIC-MCC method.The lifetime prediction research of 30cm ion thruster was carried out.The grid hole etching rate，electric field and ion extraction characteristics were analyzed，and the lifetime prediction value was given.The simulation results are in good agreement with measured values，and the error is less than 20%，which shows the modification of the model based on the measured values of grid holes in each life test section is effective.According to the simulation results，the deceleration grid is the first to fail after the 10000h life test.The estimated lifetime of 30cm ion thruster under the maximum（3kW）condition is 36000h，which can meet the long-lifetime requirements of the electric propulsion system for the small celestial body exploration mission.