Experimental characterization of a micro-hall thruster

The operation and performance of a micro-Hall thruster are characterized. The thruster is coaxial in design, with a 0.5 mm channel width and 4 mm outer diameter. The magnetic circuit includes a samarium cobalt permanent magnet generating approximately 0.7 T at the exit plane and 1 T inside the channel. Operation with a commercial hollow cathode neutralizer is achieved in the 10-40 W power range with an anode flow rate of 0.12-0.20 mg/s of xenon. The measured thrust is in the range of 0.6-1.6 mN for an anode flow rate of 0.17-0.20 mg/s and an applied voltage of 110-275 V. Anode thrust efficiency and specific impulse are in the range of 10-15% and 300-850 s, respectively, for the same conditions. Relatively broad ion energy distributions and large beam divergence are observed from an analysis of the plume using a retarding potential analyzer and ion current probe. The discharge exhibits the characteristic Hall thruster "breathing mode" instability in the 35-70 kHz frequency range.