金刚石对霍尔推力器通道壁面抗溅射性能的影响

Effect of diamond on sputtering resistance performance of Hall thruster channel wall

为了提高霍尔推力器的寿命,提出将放电通道内的氮化硼陶瓷材料换为金刚石的方法,以此来提高推力器的抗溅射性能。文章主要通过研究金刚石对推力器磁场的影响及其二次电子发射特性,分析了以金刚石作为通道壁面的可行性。文章还采用称重法对镀上金刚石的氮化硼陶瓷靶材试件进行离子轰击溅射试验,使用半经验公式求出金刚石的溅射产额与离子入射角度的关系,并应用粒子运动模拟程序预测金刚石壁面通道半径的变化,得到壁面削蚀速度。试验结果表明,金刚石在不同入射角度下的溅射产额比氮化硼陶瓷相对减少75%。壁面轮廓模拟结果表明,金刚石能使通道壁面的削蚀情况得到改善,0.7mm厚的金刚石可以抵抗大约5 000~6 000h的溅射削蚀,对于提高霍尔推力器的寿命有一定的意义。

In order to lengthen the lifetime of Hall thruster, the BN ceramic channel wall was changed to diamond wall,which can improve the sputtering resistance of thruster.The diamond？s influence on magnetic field and secondary electron emission was considered to analyse the practicability. In addition,the BN ceramic test pieces with diamond film were under ion sputtering experiment by weight method. The relationship between the sputtering yield and the on mcident angle was obtained by semi-empirical formulation method, and was used in particle movement simulation program to forecast the shape change of diamond channel wall to obtain the corrosion rate. The experiment results show that the sputtering yield of diamond s relative decreased by 75% compared to the BN ceramic in different incident angles. The simulation results show that the diamond is good at improving the corrosion situation of channel wall,and 0.7mm thickness diamond filmcan resist the ion sputtering for 5000？6000h,so it is helpful to improve the lifetime of Hall thruster.