Advancing the Microcathode Arc Thruster: Effect of the Ablative Anode

摘要

Presented is the ablative anode microcathode arc thruster (AA mu CAT). The AA mu CAT is a new concept that comes from the microcathode arc thruster (mu CAT), which implements the idea that an ablative anode can significantly improve the thrust-to-power ratio as a result of additional utilization of electron current flowing to and ablating the anode. Three versions of the AA mu CAT were analyzed, and the results were presented and compared to the standard mu CAT. Total ion current, ion velocity, and erosion rate measurement experiments were performed to characterize the thrusters. For the ion current evaluation, each combination was tested with three annular permanent magnets of differing strengths: 0.1, 0.143, and 0.3 T. All three thrusters achieved approximately 36% cathodic jet transport efficiency when equipped with the 0.1 T magnet. The result of the ion velocity testing showed that each system achieved similar ion velocities (10-13 km/s). The goal of this exercise was to determine if having an ablative anode, in addition to cathodic ablation, would increase ion current and velocity, therefore increasing specific impulse and thrust in comparison with the standard mu CAT. From the experiments presented in this paper, this was found to be true.