Thrust performance and plasma features of low-power Hall-effect thrusters

Abstract

The closed-electron-drift Hall-effect accelerator is a promising thruster in space. The effects of magnetic field shape and strength on Hall thruster performance were studied using 1-kW-class THT-series Hall thrusters. The discharge current characteristics were sensitive to magnetic field shape and strength. The thrust for the THT-IIIA thruster with more intensive concentration of magnetic field near the acceleration channel exit, i.e., with a smaller magnetic field at the anode was slightly higher than that for the THT-III thruster. The THT-IIIA thruster could be stably operated at a higher magnetic field strength than that for the THT-III thruster. As a result, for the THT-IIIA thruster, a higher thrust efficiency was achieved with a lower discharge current and a higher thrust. Furthermore, Hall thruster flowfield analysis was made to understand inner physical phenomena. Both ionization and acceleration were found to efficiently occur in a thin region with a few mm thick near the acceleration channel exit. The calculated thruster performance roughly agreed with the experimental ones.