Development of a Miniature Microwave Discharge Neutralizer for Miniature Ion Engines

Abstract

For the improvement of the performance of a miniature microwave discharge neutralizer, the dependencies of the performance of a neutralizer on the microwave frequency, magnetic field strength, antenna length among other factors were investigated. Extracted electron current strongly depends on magnetic field strength and microwave fre-quency, and the optimal magnetic field depends on the operational condition. Overall, extracted electron current was achieved 19 mA at xenon mass flow rate of 5 µg/s, incident microwave power of 2 W and collector applied voltage of 30 V. The demonstrated performance is enough for practical use as a 30 W class microwave discharge ion engine for 50 kg class satellites.