Research On The Design And Performance Optimization Of A 100-watt Cylindrical Hall Thruste

Micro-nano satellites have a short development cycle,high functional density,and low launch cost,and have been widely used in space missions such as communication,navigation,remote sensing,and ocean detection.Most spacecraft use Hall thrusters as their power source,and the related technology of Hall thrusters has become mature after years of development,performing well in the field of medium and high power.In order to better serve micro-nano satellites,Hall thrusters have begun to develop towards low power,low cost,miniaturization,and high thrust-to-power ratio.Currently,there are still issues with low efficiency and severe plasma erosion within the ceramic channel in low power Hall thrusters.This paper explores the influence of magnetic field configuration on thruster performance,and optimizes the magnetic field structure by changing the length of the magnetic shield to improve thruster performance.Firstly,a DC discharge coupling model was established for a cylindrical Hall thruster to investigate the influence of magnetic field configuration on its performance.The plasma inside a Hall thruster belongs to low temperature and low pressure plasma.Based on the practical working condition of Hall thrusters,the drift-diffusion model was employed in the simulation module,which is suitable for low temperature and low pressure plasma and can calculate faster.A simulation model was established using COMSOL simulation software,involving the coupling of static magnetic field,electrostatic field,plasma,and neutral gas transport modules to achieve accurate calculation of multiple physical field couplings.The initial simulation result indicated a thrust of approximately 0.799 m N calculated by wall electron current density.Secondly,based on the prerequisite conditions for the stable operation of Hall thrusters and the simulation results,the optimization direction of the magnetic field structure was determined.Simulation was employed to explore the influence of the magnetic shield length on the magnetic field structure.When the magnetic shield length L = 6,the distribution of the magnetic field in the channel was the most appropriate,and the radial drift of electrons continued at the channel exit,which enhanced the collision probability between electrons and neutral gas.The restraining effect of other magnetic shield lengths on electron motion was inferior to that of L = 6.After adding the magnetic shield,the magnetic field intensity on the anode surface continued to increase.Excessive magnetic field strength may cause anode overheating,affecting the thruster performance.Further research is required in this regard.Finally,the simulation parameters were matched with the dimensions of the thruster structure,and a prototype of the cylindrical Hall thruster was developed.A high vacuum experimental platform that meets the prototype size was constructed under laboratory conditions to conduct performance tests on the prototype.When the discharge voltage was300 V and the anode mass flow rate was 25 sccm,the thrust produced by the thruster was approximately 0.65 m N,and the specific impulse was 140 s.