Numerical and Analytical Thrust Performance Analysis of DC Ring Cusp Discharge Ion Thruster

Abstract

The DC (Direct current) ring cusp discharge ion thruster is an electrostatic type ion thruster used in numerous on-orbit and deep space applications. 1 In this study, numerical and analytical models of DC ring cusp discharge thrust performance are calculated using numerical simulations of the analytical thrust modeling. The analytical model is presented considering the thrust generated by the ion optics. The numerical simulations have been performed using a 2D (Two Dimensional) axisymmetric model of the DC ring cusp discharge ion thruster as shown in the figure. The effects of the charge exchange (CEX) interactions and the ion beam profile are to realize the phenomena that generate significant thrust in the DC ring cusp discharge ion thruster. Thrust performance analysis of the numerical and analytical model was investigated by calculating thrust, for the given beam voltage and current. All the numerical simulations were performed using COMSOL Multiphysics finite element software package. The 30cm diameter thruster model is optimized to use Xenon as the propellant gas. The chamber pressure is maintained at 0.5 Torr. The ion thruster has back propellant injection to maximize the mass flow rate efficiency. The magnetic field is consisting of three-ring cusp 0.24T magnets to form the magnetic field boundary. The hollow cathode has an orifice diameter of 1.25mm. The mass flow rate, ion charge, and mass are considered constant. The maximum thrust resulted in the numerical model simulations and analytical model were 5.2mN and 20.2mN respectively. The experiment was conducted in the beam voltage range 400V– 600V. The experiment showed that the variation of beam voltage is a method of thrust regulation. The thrust performance of the DC ring cusp discharge ion thruster suggests that it is well suited for microsatellite propulsion applications.