Reduction of Leak Current during OFF Period in PWM Control of Ion Engine

Abstract

In order to improve the thrust performance of ion thrusters with pulse width modulation control, optimized grid system by numerical simulation was used for the reduction of leak ion beam current. The effect of reduction of mass flow rate on thrust performance was also investigated for the improvement of propellant utilization. The leak current was decreased from 30% to 3.5%, achieving dramatic improvements. The propellant utilization was also improved from 0.25 to 0.48 by decreasing the xenon mass flow rate from 9.8 ug/s(0.1 sccm) to 4.9 ug/s(0.05 sccm).