Operation of a lightweight power conditioner with a hollow-cathode ion thruster

Experimental system studies are under way on solar-electric primary propulsion for deep space probes, using a 20-cm-diam electron-bombardment ion thruster that has a hollow cathode as an electron source and mercury as the propellant. The thruster output power can be varied from 1000 to 2000 w with small penalties in total efficiency. A lightweight power conditioner, originally designed for operation of an ion thruster employing an oxide cathode, has been modified to accommodate the hollow cathode. The thruster and power conditioner redesign, thruster control loops, and recycle procedure to clear sustained arcs are described. Data are presented on operation with the thruster.