Flow Rate Influence on Ion Beam Characteristics for Externally Wetted Electrospray Thrusters

Abstract

Electrospray thrusters have attracted attention as compact propulsion systems capable of precise thrust control. The thrust of electrospray thrusters depends on the ion beam current and ion mass, and the form of the emitted ions varies depending on the flow rate of the ionic liquid supplied to the emitter. Therefore, it is necessary to understand the effect of the flow rate on the beam characteristics in order to optimize the thruster performance. In this study, we have developed a pressure-based flow control system to vary the flow rate of the ionic liquid to externally wetted emitters, and measured the ion beam currents to evaluate their characteristics. We find that the beam current tends to increase with increasing supply pressure, and that the current–voltage characteristic depends on the flow rate.