20-cm ECR plasma generator for xenon ion propulsion

Abstract

This paper presents the development status of a 20-cm diameter microwave discharge ion thruster which generates 25 ∼ 30 mN of thrust with an electric power of 1 kW. By optimizing the discharge chamber length, magnetic field and propellant flow injection, ion currents of up to 530 mA at a net microwave power of 100 W had been obtained at a frequency of 4.25 GHz with a coaxial cable to circular waveguide transformer. Almost the same performance has been achieved with a new antenna directly inserted into the discharge chamber, which removes the need for a long circular waveguide. Higher frequencies up to 5.8 GHz and stronger magnets have been tested for performance improvement and turned out to be very promising.