Advances in field emission electric propulsion (FEEP) efficiency through Monte Carlo optimization of electrostatic lenses

Abstract The small size and possibility of launching multiple satellites with a single rocket have made CubeSats an attractive emerging technology. The Indium Field Emission Electric Propulsion multi-emitter (IFM) Nano thruster represents a pioneering FEEP propulsion system integrated within CubeSats, with a very high specific impulse (Isp). However, there is a pressing need to enhance the performance of these thrusters to achieve optimal commercial efficiency. In this regard, the current research delves into the impact of electrostatic lenses for evaluating their effects on thrust, average particle angle (Θ), and I sp of the IFM Nano thruster through Multiphysics simulations. The employed technique involves incorporating the Monte Carlo (MC) optimization method to refine the focusing electrostatic lens and consider the combined contributions of electrons and ions in the neutralization process. The findings indicate that if ions do not collide with the walls, a smaller radius and greater height of the electrostatic lens will yield more favorable outcomes. In the scenario involving electrostatic focus lenses, altering the Θ from 29.4° to 11.86° resulted in a notable 47% increase in thrust, accompanied by an enhanced percentage of receiving energy (PRE) from 54% to 90%. These changes occurred while maintaining the constancy of electrical circuits and applying voltages.