微波干涉法诊断MPT羽流特性研究

建立了一套应用于模拟真空环境下采用微波干涉法诊断MPT的羽流电子数密度的实验装备,对采用氩气为工质的微波等离子体推力器的羽流进行了测量,得到了电子数密度的轴向分布,以及电子数密度随推力器功率和工质流量变化的趋势。实验结果表明:MPT羽流电子数密度在距喷管出口300mm后为0.5×1016/m3～2×1016/m3,且等离子体密度随着微波功率和工质流量的增大而增大,电子数密度的空间分布及变化规律与Langmuir探针的诊断结果一致,验证了微波干涉法在MPT羽流诊断上的可行性。

Microwave Plasma Thruster Plume Diagnosis Using Microwave Interference Method

An experiment system for Microwave Plasma Thruster (MPT) plume diagnosis with microwave interference device was built,and the electron density of MPT plume with propellant Argon was diagnosed,and the axial distribution of electron density and the influence of thruster power and propellant flowrate on electron density is determined. Experimental results show that the electron density of MPT plume is about 0. 5 × 1016 /m3 ～ 2 × 1016 /m3 and it decreases along the axial direction when the distance from thruster nozzle is more than 300mm; and that the enhancement of thruster power and propellant flowrate can increase the electron density effectively. The electron density distribution and changing trend are in good agreement with the Langmuir probe diagnosis result,which verified the feasibility of microwave interference method on MPT plume measurement.