Effect of disruption of anode potential symmetrical supply on Hall thruster discharge

During a long-term discharge of a Hall thruster, local overheating on the anode surface occurs and its location shifts randomly. The asymmetrical supply of anode potential is thought to be the cause. To investigate their relationship, a bias voltage is applied on one piece of a quartered anode to realize the asymmetrical supply of anode potential. Variations of both the current and temperature of each anode piece are measured and analyzed. The results indicate that the disruption of the anode potential symmetrical supply does not affect the total anode current; however, it enhances the current oscillation. As the bias voltage increases, the current concentrates gradually on the high-potential part of the anode, accompanied by an increase in the local temperature. Changes in the E-z x B-r drift direction, magnetic field strength, discharge voltage, and anode flow rate do not affect the above-mentioned laws. Preliminary analysis shows that the formation of a local electric field near the anode and the generation of an extra E-theta x B-r drift are the main causes, which can affect the movement of electrons in the near-anode region greatly.

Automated summary

The study found that asymmetrical anode potential supply can exacerbate current oscillation and cause current to gradually concentrate on the high-potential part of the anode, accompanied by an increase in local temperature.