Investigation on the method of improving the performance of hollow cathode thruster with an outer emitter

To improve the performance of the hollow cathode as a thruster, a hollow cathode thruster with an emitter mounted on the top of the keeper was developed. It is found that the thrust and specific impulse generated by hollow cathode with the outer emitter are higher than those produced by hollow cathode. A further study shows that the ion current and ion energy in hollow cathode with an outer emitter are both higher than those in hollow cathode, and it infers that there exist ions acceleration in thrust production mechanism in hollow cathode thruster with an outer emitter causing improvements in thrust and specific impulse.