Abstract: In order to study the factors affecting the lifetime of the ring electrodes micro-cathode arc thruster, firstly possible factors are analyzed. Then the influence of the current parameters on the resistance between the cathode and the anode, the thermal performance of the thruster under different powers and the influence of the power on the erosion of insulator are studied through experiments. The experimental results show that for the extension of the lifetime of the thruster, it is necessary to control the larger discharge current of the thruster, so that the resistance between the cathode and the anode is dynamically balanced and maintains at 0.5-10 kΩ, and to select the appropriate discharge power. The high temperature withstanding capacity of each material should be considered in the power threshold. Additionally, the erosion of insulator is the main factor limiting the lifetime of the thruster, and reducing the discharge power helps to slow down the erosion.

Key words: Ring electrodes micro-cathode arc thruster, Coating resistance, Power threshold, Erosion of insulator