Wall material effects in a minimized electron cyclotron resonance ion thruster

Wall material effects in micro-ion thrusters attracts significant research attention with respect to weakening plasma wall loss, and increasing propellant utilization to obtain high-precision and low-thrust of micro-Newton propulsion, as required in new generation space observation missions. In this study, we compare the performance and discharge characteristics of different wall materials, namely, Mo and Al₂O₃ in a minimized electron cyclotron resonance ion thruster. The results show that the propellant utilization and specific impulse of the ceramic are about three times higher than those of the Mo at a low mass flow rate of 0.03 sccm. In addition, a planar Langmuir probe is used in the discharge chambers, and the results show that the secondary electron emission of Al₂O₃ effectively reduces the electron temperature, increases the electron density, and results in high efficiency. These results are helpful for improving the performance of micro-ion propulsion devices for microsatellites and space-borne gravitational wave detection missions.