Abstract: Aiming at the complexity of the thruster discharge chamber design in variety of operation modes， by using the equivalent magnetic circuit method， the magnetic circuit model of the ion thruster magnetic field system is established to achieve the conversion between the electromagnet and permanent magnet. Based on this model， and combined with the finite element method， the physical dimension of the permanent magnet which has the same effect with the electromagnet is obtained. And the ion thruster chambers under the two above states are compared. Results showed that after magnetic circuit conversion the relative error of magnetic induction intensity in key points is less than 5%. In addition， the discharge loss of 141.8W/A， and anode shock voltage of 10V in permanent magnet structure meets the requirements of magnetic circuit conversion and the targets of magnetic field design， which shows the effective of the equivalent magnetic circuit model and the feasible of the method are verified.

Key words: Ion thruster；Electromagnet；Permanent magnet；Magnetic circuit model

摘要： 针对多种工作模式下推力器放电室磁路设计的复杂性问题，为实现电磁体磁场向永磁体磁场的磁路转换，利用磁路等效法，建立离子推力器磁路系统的等效磁路模型。在此基础上，结合有限元理论，分析获得产生与电磁体磁场的磁路构型相同的永磁体结构尺寸，将离子推力器放电室在永磁体磁场状态与电磁体磁场状态下的磁感应强度进行对比。结果表明:磁路转换后关键点磁感应强度相对误差低于5%，且永磁体样机工作放电损耗为141.8W/A，阳极震荡电压为10V，符合磁路转换要求和磁场设计目标，验证了等效磁路模型分析结果的正确性及方法的可行性。

关键词: 离子推力器；电磁体；永磁体；磁路模型