Abstract
Basic experiments were carried out using the THT-IV 1-kW-class Hall-effect plasma accelerator to examine influences of magnetic field shape and strength, and acceleration channel length on performance characteristics for space propulsion. Thrusts were measured with varying magnetic field and channel structure. Exhaust plasma diagnostic measurement was also made to evaluate plume divergent angles and voltage utilization efficiencies. Ion current spatial profiles were measured with a Faraday cup, and ion energy distribution functions were estimated from data with a retarding potential analyzer. The Hall thruster was stably operated with the highest performance under an optimum acceleration channel length of 20 mm and an optimum magnetic field with a maximum strength of about 150 Gauss (0.015 Tesla) near the channel exit and with some shape considering ion acceleration directions. The optimum operational feature was discussed with measured plasma plume characteristics.
