Axial emission characteristics of an ionic liquid electrospray thruster with a circular emitter

Ionic Liquid Electrospray Thrusters(ILETs) are well suited for micro-nano satellite applications due to their small size, low power consumption, and high specific impulse. However,the limited thrust of a single-emitter ILET restricts its use in space missions. To optimize the performance of ILETs and make them suitable for a wider range of space missions, we designed a Circular-emitter ILET(CILET) to convert a one-dimensional(point) emission into a twodimensional(line) emission. The CILET can self-organize multiple Taylor cones simultaneously.The cones were photographed and the axial emission currents were measured under different voltage and pressure difference conditions with a CILET experimental system. The emission can be divided into two stable states and one unstable state based on the flow and current characteristics.The current in Stable state I increases non-linearly with the voltage, while that in Stable state II is nearly linear with respect to the voltage. The number of cones increases with the voltage in stable states, while the cones become short and crowded under high-voltage conditions. The variation law of the number of cones can be explained with the self-organization theory. The variation in the current exhibits a good correlation with the number of cones. This study demonstrates the feasibility of circular emitters and experimentally indicates that the emission current is improved by approximately two orders of magnitude compared to that of a single capillary.