Experimental study on two kinds of electron conduction routes in a multi-cusped field thruster

The multi-cusped field thruster is a novel plasma propulsion device. The typical thruster features extremely large thrust throttle ability (from 200 μN to 150 mN), high thrust density (12 mN cm2) and long lifetime (>18750 h). In this paper, a differential algorithm is used to extract the intensity image of plasma bridge. The results indicate that there are two kinds of electron conduction routes in the nearfield plume region. The formation of electron conduction routes is attributed to the magnetic mirror effect in the multi-cusped field. The experimental results show that with the cathode moving towards downstream, the electron current in inner route increases but the electron current in outer route decreases. Nevertheless, it is validated that the change of electron conduction routes affects the distributions of ionization regions: the increase of inner route electron current promotes the ionization in exit region and the decrease of outer route electron current restrains the ionization in upstream region. © 2019 IOP Publishing Ltd.