微阴极电弧推力器的设计与试验

Design and Experiment of Micro-Cathode Arc Thruster

关键词:  微阴极电弧推力器  功率处理单元  阴极斑点  离子速度  元冲量

Key words:  Micro-cathode arc thruster  Power processing unit  Cathode spot  Ion velocity  Impulse bit

摘要:

微阴极电弧推力器具有体积小、重量轻、功耗低、比冲高等优点，是微纳卫星空间推进的理想选择。为了研究其关键特性以及基本性能，设计了一套环形微阴极电弧推力器样机，包括推力器本体和功率处理单元。高速摄影对推力器点火的观测验证了磁场存在时阴极斑点的旋转，并获得了阴极斑点旋转速度与磁场强度的关系。通过飞行时间法、打靶法分别对离子速度、元冲量进行了测量，测量结果表明:推力器出口离子的轴向平均速度在15～30km/s，没有磁场时，元冲量为0.132μN·s，磁场强度为0.0457T时，达到0.262μN·s，推力器平均推力大小在μN量级。通过研究得到:微阴极电弧推力器烧蚀均匀，性能易于调节，适用于微纳卫星。

Abstract:

Micro-cathode arc thruster has the advantages of small volume， light weight， low power consumption and high specific impulse. It is an ideal choice for the space propulsion of micro-nano satellite. In order to study the key characteristics and basic performances， a prototype of the annular micro-cathode arc thruster， including the thruster and the power processing unit， is designed. The thruster ignition is observed using high speed photography， verifying that cathode spot rotates in the presence of magnetic field， by which the relationship between the cathode spot rotation speed and magnetic field strength is obtained as well. Through the time of flight method and shooting method， ion velocity and impulse bit are measured respectively. The measurement results show that the average ion velocity nearby thruster exit is between 15～30km/s. When the magnetic field does not exist， impulse bit of the thruster is 0.132μN·s， while the magnetic field strength is 0.0457T， the impulse bit increases to 0.262μN·s. The average thrust is on the order of μN. The study shows that， the micro-cathode arc thruster has a uniform ablation， is easy to adjust and suitable for micro-nano satellite.