Abstract: In view of the current situation that the design of the magnetic circuit of Hall thrusters mainly relies on manual adjustment by designers′ experience, this paper establishes an efficient and high quality magnetic circuit optimization design method to solve the problem of low efficiency in adjusting individual magnetic circuit sizes in a step by step manner, which cannot meet the increasingly refined magnetic field requirements. Through extensive research on flight verified thrusters, the description method and range of magnetic field parameters are clarified, and the magnetic field criteria for Hall thruster design are refined. Based on this, size optimization based on finite element method is adopted, embedding the magnetic field requirements into the constraints of magnetic circuit optimization. Finally, the magnetic circuit design is completed under the automatic search and optimization of multiobjective optimization algorithm. A typical magnetic circuit structure form with double magnetic shields is selected as the initial magnetic circuit, and a 1.35kW level thruster is used for verification. The results show that the optimized magnetic circuit quality is reduced by 34.9%, and the excitation power is reduced by 5.6%. The magnetic field symmetry is significantly improved. Meanwhile, the maximum magnetic field intensity is increased by 8.3%, and the magnetic field gradient is increased by 6.4%. The size based optimization magnetic circuit design method proposed in this paper is suitable for Hall thrusters of various power levels, allowing the magnetic field requirement parameters to vary over a wide range and supporting the simultaneous adjustment of tens of key dimensions, optimizing the magnetic circuit to better meet the magnetic field design requirements.

Key words: electric propulsion technology, Hall thrusters, finite element analysis, optimization design