Performance model of vacuum arc thruster with inductive energy storage circuit

A vacuum arc thruster is a type of micro-thruster based on pulsed ablative vacuum arc discharge. A simple inductive energy storage circuit in a vacuum arc thruster is particularly suitable for CubeSats because of its compact size and low cost. In practice, it is necessary to predict the thruster performance with the given design parameters. However, unlike the pulsed plasma thruster, there is a lack of integrated performance models for the vacuum arc thruster that cover all three processes of the circuit, ablation, and acceleration. In this study, a circuit model that accounts for the real characteristics of the components, such as the inductor, was developed. Discharge experiments were conducted to validate the proposed circuit model. The current-time curve and discharge energy were calculated and had relative errors of less than 15%. The performance model was obtained by combining the circuit model with the existing ablation and acceleration models. The input power and thrustto-power ratio were predicted, and the results were compared to a flight test of the thruster prototype. The error in the input power was small, whereas the error in the thrust-to-power ratio was relatively large. This large error can be explained by the differences in the surface conditions.