离子推力器放电损耗特性研究

Research on the characteristic of discharge loss for ion thruster

为了明晰放电损耗能量分配机制,对离子推力器放电损耗特性进行了研究。基于等离子体经典理论,分析了放电室等离子体产生及输运过程,得到放电室各项能量损耗表达式,并计算了离子推力器稳态工作下放电损耗组成比例,在此基础上,进一步研究了放电损耗随工质利用率变化关系。结果表明,放电能量损耗比例中,电离损耗为17%,激发损耗为18%,电子能量损耗为25%,离子能量损耗为35%;随着工质利用率增加,电离能量损耗保持不变,激发能量损耗呈缓慢下降趋势,离子能量损耗均呈缓慢增加趋势,电子能量损耗在工质利用率超过80%之后呈快速增长趋势。应用实验结果对放电损耗随工质利用变化关系进行验证,最大误差小于3%。

To clarify the mechanism of energy distribution in the process of discharge loss in ion thruster,the characteristic of discharge loss was studied. Based on the classical plasma theory,the production and movements of plasma were analyzed,and the expressions of each energy loss were obtained. Furthermore,the ratio of discharge loss was calculated in steady-state operation of ion thruster. The results indicate that ionization energy loss is 17%,excitation energy loss is 18%,electron energy loss is 25%,ion energy loss makes up 35%; and the relation of discharge loss and mass utilization efficiency is calculated and validated. The results indicate the maximum error is no more than 3%.