The influence of the inclination of strong magnetic field lines on the performance and plume divergence of a magnetically shielded Hall thruster

It has been recognized that the application of magnetic shielding technology deteriorates the plume divergence efficiency of a Hall thruster. To try to alleviate this effect, three magnetic shielding configurations with different inclination directions of the lines of force in the strong magnetic field region are designed via the introduction of a peripheral coil surrounding the thruster body, and their influence on the performance and plume divergence are experimentally evaluated in this study. The measured results show that the performance and plume distribution vary significantly with the change in the inclination direction of the lines of force. Particularly, different to the unshielded Hall thruster that exhibits the best performance and minimal divergence when the strong magnetic field lines are non-inclined (perpendicular to the thruster axis), the magnetically shielded Hall thruster has the largest thrust and the smallest divergence angle when the strong magnetic field lines are inclined inward. Further theoretical research indicates that this is mainly due to the change in the ion acceleration process under the magnetic shielding discharge. This study is significant and instructive for the optimized design of magnetically shielded Hall thrusters.