30厘米多模式离子推力器1200小时磨损试验研究

1200 h Wear Test of a 30 cm Multi-Mode Ion Thruster

针对小天体探测主推进任务应用需求,开发了30 cm多模式离子推力器。为了验证该推力器长期工作性能,发现过早失效模式,并获取关键部组件磨损数据,在4种典型工作点下开展了1200 h磨损试验,本文给出了试验方案和试验结果。试验结果显示:30 cm多模式离子推力器1200 h工作期间功率、推力、比冲和效率均满足任务要求,未发现性能衰减现象;经历1200 h工作后,放电室未发现溅射沉积多余物;阴极顶和中和器顶小孔工作300 h后出现增大现象,其后基本保持不变;除减速栅最边缘小孔直径增大约4%外,栅极小孔直径在测量误差内未发现明显增加现象。

A 30 cm-diameter multi-mode ion thruster is developed to meet the primary propulsion requirement of asteroid exploration mission.A 1200 h wear test of the ion thruster at four typical throttling points is carried out to verify long-duration operation ability,identify premature failure modes and obtain wear data of critical components.The test scheme and result are presented.The result shows that the power,thrust,specific impulse and efficiency all meet the requirement and there is no performance degradation during the 1200 h operating;there is no sputtering contamination in discharge chamber after the 1200 h wear test;the top orifice diameters of neutralizer and cathode increase at first 300 h operation and then keep constant;and the grid apertures have no obvious enlargement within the accuracy of measurement,except for the apertures at the edge of the decelerator grid,whose diameters increase by about 4 percent.