Simulation and test of discharge performance of high-power Hall thruster for space solar power stationsOA

Development of space solar power stations(SSPS)requires high-power Hall thrusters as propulsion.To assess the HET-450 high-power Hall thruster aiming at SSPS,a Particle in Cell(PIC)based model is built to simulate the interplay of discharge voltage,gas flow rate et al with the thruster discharge performance.To test the PIC simulation results,a high-power Hall thruster test platform is constructed for thruster characterization.By comprehensive simulation,the scope of electrical and mechanical operation is determined to match the thruster configuration.From simulation,the atomic density,electrical field and electron temperature distributions inside the thruster discharge channel are clarified and therefore the ionization and acceleration dynamics of thrust formation is discussed.In addition,the model is able to figure out the discharge current and thrust output for any operation conditions and therefore measurement of the thruster performance is carried out using the test platform to verify the model reliability.The results of discharge current and thrust obtained from simulation and experiment agree well to each other.The simulation results show that the discharge voltage varying from 300 V to 500 V raises the ionization efficiency and increases the discharge current,thrust and anode efficiency.However,for the discharge voltage over 500 V,the thruster walls are overheated,due to high ion flux on the thruster walls and resultant high ion recombination rate.Once the wall overheating occurred,the working fluid utilization and therefore the anode efficiency decreased.Thruster performance optimization based on simulation gives that the thruster can output 2.1 N of thrust and as high as 60%of anode efficiency using 500V of discharge voltage and 80mg/s of flow rate,which indicates that the HET-450 design scheme works well.