Development of a 15-kW Class RF Plasma Source for VASIMR Type Space Propulsion with Magnetic Nozzle*)

Abstract

A radiofrequency (RF) plasma source was developed for space propulsion using an FET based RF inverterpower supply with a power of 15kW. The operating frequency of the RF power supply was approximately 200 kHz. By adjusting the magnetic field strength near the RF antenna to around 10mT, we achieved high density argon plasma on the order of 1019 m−3. The plasma passed through a region of strong magnetic field (approaching 1 T), provided by a pulsed capacitor bank for ion cyclotron resonance heating (ICRH). The plasma radius was reduced by the converging magnetic field, and the high plasma density was retained in the downstream ICRH region.