PhD Seminar Series: “Recent Progress on RF Ion Thruster Development at KAIST-APRIL”

Abstract: 

Radio-frequency (RF) gridded ion thrusters (RITs) have been considered and applied to deep space missions, offering high-power, high-efficiency capability. Traditionally, validating thruster performance requires extensive ground tests before launching a flight model, which required large, high-vacuum facilities. Because of such complicated and time consuming works, computational simulations have been preferred to simply assess detailed characteristics of ion thrusters relevant to thrust performance. Here, we present a comprehensive numerical simulation of an RF inductively coupled plasma (ICP) ion thruster using an equivalent 2D-axisymmetric model in a single tool, COMSOL Multiphysics. Within a single software framework, we sequentially solve for rarefied gas dynamics, time-averaged plasma properties, and ion beam extraction by employing relevant physics modules. This suggested method enables us to numerically test a new RF gridded ion thruster simply with varying design factors (i.e., chamber dimensions, etc.) and operating parameters (i.e., coil power, flow rate of supplying fuel gas, etc.), while maintaining affordable computational cost. Our simulation results yield mass utilization and electrical efficiencies that closely match values reported in earlier studies, thereby validating the numerical model. Based on this numerical study, we recently developed a prototype of the RF ion thruster and currently preparing the necessary facilities for further experimental research.