Reaserch On Plume Effect And Plume Shields Of The Electric Thruster

Based on the problem of pollution from the plume of electric thrusters during their application, systemic study about the security of hall thruster plume and ion thruster plume was made in this paper.Hybrid-PIC was employed for the movement of the plasma, and the collision of between ions and atoms was considered by MCC. Some appropriate conditions were confirmed by the research on the ion density distribution at the exit of thrusters. The simulation results were compared with some measurement data at the same backpressure. Then, the distribution of plasma plumes in space was predicted.Backflow ions from the charge exchange collision in plume would lead to some negative effects, such as sputtering, heat deposition and moment disturbance. Based on the results of the plume simulation, the estimation models of the three effects were built. Took the typical spacecraft as an example, some assessment results were obtained. Then, in order to verify the models, some comparisons with other results were made. In addition, the numerical model of charging and discharging effects was stated, and the surface potential and current were simulated of the typical spacecraft.According to different missions of electric thrusters, the pollution of plumes was estimated for two mounting position of thrusters on spacecraft. The results of hall thrusters、ion thrusters and magnetic focusing hall thrusters were compared for the first case. Then, because of the smaller divergence angle of the magnetic focusing hall thrusters, some optimization for the mounting position of the hall thruster for the mission of position holding was made. The results indicated that the ion thruster and the magnetic focusing hall thruster had more advantages in the aspect of plume security. Application of the magnetic focusing hall thruster not can only reduce the pollution of the solar array but also decrease the thrust loss.The plume of the electric thruster would cause negative effects to spacecraft surface, so some protective structures should be designed in some cases. The cover glasses on solar panel had high light transmission and the input power would decease if it was polluted by sputtering or heat deposition. Several defense schemes for different thruster position were proposed at the last section of this paper. Then, the pollution under these shields were evaluated and compared. The study about the plume shield provided some references for the related work in future.