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

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.

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