Antenna Design Method and Performance Improvement of a Micro Ion Engine Using Microwave Discharge

Abstract

In this study, we are proposing a novel miniaturized ion engine system µ1. Recently microspacecraft and propulsion system to be installed there have attracted a lot of attentions. To accomplish the miniaturization of spacecraft component, multifunctionalization of devices are key technologies. The ion engine we are proposing here is distributed on microspacecraft and give a number of functions and strong redundancy to the spacecraft. To realize this concept, we introduced a novel idea for an ion engine system. That is to use single plasma source as both ion beam source and neutralizing electron source only by electrical connection. This ion engine system is released from the necessity of a number of neutralizers. Our concept requires a plasma source driven by very low power microwave. Here we proposed an antenna design method for a small plasma source using microwave discharge, and developed a miniaturized ion engine. As a result, the performance of the miniaturized ion engine was improved up to the ion production cost of 240 V and propellant utilization efficiency of 40 % at the input microwave power of 1.0 W and mass flow rate of 0.15 sccm.