Coupling of a shared hollow cathode with a dual Hall thruster cluster

Abstract Hall thruster clusters or arrays are a flexible option for controlling thrust vector, extending lifetime, or enhancing power of the propulsion system. However, the coupling relationship between thrusters and hollow cathodes becomes more complicated due to the intersected plasma plumes of multiple Hall thrusters. In this study, plasma probes were utilized to experimentally investigate the discharge characteristics and plasma plume structure of the thruster cluster plume under different cathode coupling position conditions. Experiments have shown that the synergistic promotion effect of the thruster cluster plumes has a vital influence on the coupling relationship between the thruster cluster and the shared hollow cathode. The plume of one thruster could become a source of electrons for the adjacent thruster, significantly contributing to the ability of the thruster to capture electrons. It can reduce the spatial potential of the plume and enhance the potential drop within the discharge channel, facilitating ionization with an increase of the discharge current by up to 12.8%. Thus, the effect of the hollow cathode position on the thruster discharge characteristics is significantly weaker for the thruster cluster than for the single thruster. In general, this study reveals the coupling law of a dual thruster cluster with a hollow cathode, contributing to the design of a shared cathode for a thruster cluster.