Review of non-conventional Hall effect thrusters

Electric propulsion has become the favored approach for Low Earth Orbit (LEO) maneuvers, resulting in substantial expansion in its use in the satellite industry. The Hall effect thruster’s (HETs) high specific impulse and thrust-to-power ratio allow for a wide range of in-space propulsion applications, making it a viable alternative for various space missions. In the space sector, the mass production of HET is currently underway to fulfil the needs of the satellite industry for performing various maneuvers such as orbit boosting, station keeping, deorbitation, collision avoidance, and inter-orbital transfers. The increase in mass production has caused engineering challenges in manufacturing, necessitating an efficient batch production process to guarantee flight qualification within acceptable limits. Engineering production problems may cause manufacturing defects in HET components, leading to non-uniform magnetic field. The non- uniformities in the magnetic field can be observed azimuthally in the channel in various conditions resulting from electrical shorting and geometrical constraints. It is essential to comprehend the effect of such non-uniformities in the magnetic field on the performance of Hall-effect thrusters. An approach to understanding the potential effect of non-uniform magnetic field in HET is by analyzing the efficacy of non-conventional HETs possessing non-uniform magnetic fields. The article comprehensively reviews several non-conventional HETs with distinct channel cross-section geometries, such as linear, racetrack, and wall-less configurations. The paper presents a comparative analysis between non-conventional HETs and conventional HETs operating in low to mid-power configurations for performance evaluation. The review provides discussion of the effects of non-uniform magnetic field on the reduction of optimized HET operation by the presence of heightened erosion and reduction in stability. The review study highlights the importance of optimizing magnetic field topology for developing future thruster designs with enhanced performance and utilization.