Experimental Study on the Effects of Magnetic Field Configuration near the Channel Exit on the Plume Divergence of Hall Thrusters

Experimental investigations into the effects of the magnetic field configuration near the channel exit on the plume of Hall thrusters were conducted. The magnetic field configuration near the channel exit is characterized by the inclination angle between the magnetic field lines and the thruster radial direction. Different inclination angles were obtained by varying the current ratio in the coils. The plume divergence angles were measured by a dual-directed probe. The results showed that the plume divergence angle increased obviously with the increase in the magnitude of the inclination angle near the channel exit. Therefore, in order to optimize the magnetic field for reducing plume divergence, the magnitude of the inclination angle should be reduced as much as possible. It suggests that the magnetic field configuration near the channel exit is another important factor that affects plume divergence.

Research of influence of the additional electrode on Hall thruster plume by particle-in-cell simulation

Hall thruster is an electric propulsion device for attitude control and position maintenance of satellites.The discharge process of Hall thruster will produce divergent plume.The plume will cause erosion,static electricity,and other interference to the main components,such as solar sailboard,satellite body,and thruster.Therefore,reducing the divergence of the plume is an important content in the research of thruster plume.The additional electrode to the plume area is a way to reduce the divergence angle of the plume,but there are few related studies.This paper uses the particle-in-cell(PIC)simulation method to simulate the effect of the additional electrode on the discharge of the Hall thruster,and further explains the effect mechanism of the additional electrode on parameters such as the electric field and plume divergence angle.The simulation results show that the existence of the additional electrode can enhance the potential near the additional position.The increase of the potential can effectively suppress the radial diffusion of ions,and effectively reduce the plume divergence angle.The simulation results show that when the additional electrode is 30 V,the half plume divergence angle can be reduced by 18.21%.However,the existence of additional electric electrode can also enhance the ion bombardment on the magnetic pole.The additional electrode is relatively outside,the plume divergence angle is relatively small,and it can avoid excessive ion bombardment on the magnetic pole.The research work of this paper can provide a reference for the beam design of Hall thruster.

Measurement method and results of divergence angle of laser-controlled solid propellants used in space propulsion

The plume divergence angle is an important reference index for evaluating the thrust efficiency and propellant utilization of space propulsion systems.However,the characteristics of the dynamic variation of plume divergence angle over time cannot be measured using current methods.This paper utilizes high-speed photography and image processing methods to develop a strategy that can give a quick,non-destructive and real-time detection of the divergence angle.Effectiveness of the strategy is verified,and the characteristics of plume divergence angles of different lasercontrolled solid propellants were further analyzed and fitted.The experimental results indicate that graphene could effectively reduce the divergence angle,while oxide-doped samples had larger divergence angles than alloy-doped and carbon-doped samples.