Design of magnetically enhanced hollow cathode micro-thruster: Concept and experimental research

Abstract

Recently, a large number of micro-satellites have been deployed in low earth orbit in the form of a constellation for earth observation, navigation, and communication. They have proposed new requirements for low-power propulsion systems. A hollow cathode is a type of electron source widely used in the electric propulsion, but it has low efficiency as a standalone thruster, which can-not meet the demands of micro-satellites for propulsion. In this study, a novel magnetically enhanced hollow cathode micro-thruster is designed and tested. It can be operated at anode powers in the range of 41.4–73.9 W with xenon discharge when the flow rate is 3.5 sccm, and it can generate specific impulses in the range of 551–723 s at a thrust efficiency of up to 13.1%. A Faraday probe was utilized to measure the ion current in the plume, and the propellant utilization and current utilization efficiencies reached 0.817 and 0.722, respectively, with a mass flow rate of 3.5 sccm. An RPA was applied to analyze the ion energy function distribution, and the results show that the anode voltage utilization is 0.59 at an anode voltage of 200 V. The magnetically enhanced hollow cathode micro-thruster integrates the anode and cathode, which is favorable for the miniaturization of the propulsion system.