Discharge characteristics of 100-W Hall thrusters under position matching between the anode and zero-magnetic-field region

Poor performance limits the wider application of 100-W-power class Hall thrusters. The effects of position matching between the anode and the zero-magnetic-field region (ZMFR) on the discharge process and performance improvement of 100-W Hall thrusters were investigated. The experimental results demonstrate that appropriately widening the ZMFR downstream of the anode improves the ion current and thrust, promotes plume focusing, and optimizes thruster performance. The thrust and anode efficiency is enlarged by 7.6 % and 20 % (relative value), respectively, when the ZMFR downstream of the anode is expanded by 0.2L (L is the channel length). The simulation results indicated that widening the ZMFR promoted the expansion of the high-ionization zone to the bottom of the channel, and increased the overall ionization rate. Moreover, as the ZMFR increases, the effective ion acceleration voltage increases. However, widening the ZMFR also aggravated the ion-wall interaction and reduced the propellant utilization rate. Therefore, the performance of the thrusters exhibited an optimal range as the length of the ZMFR increased. In addition, increasing the ZMFR did not affect the life of the thrusters.