Reproducibility of operating potentials for a C12A7 electride plasma-based cathode with constant keeper current control

Abstract

Hollow Cathodes are fundamental components for electric propulsion systems. In recent publications, the performance of a planar C12A7 electride cathode has been presented with promising results. This includes the endurance operation of the cathode, the heaterless ignition cycling, and the general performance mapping over a wide range of parameters. The present publication will add to these publications, presenting results of only one defined set of discharge parameters, allowing a statistical evaluation of repeated discharge operations. Overall, exceptable repeatability of the performance could be evaluated, confirming the overall performance trends observed in previous campaigns. The cathode was operated in self-heating mode using krypton as propellant in a current range of 100 mA to 600 mA. A discharge potential of 30 V with a slight increase for lower discharge currents is reported. Furthermore, means to reduce the variation in the test results by increasing the keeper current have been identified.