MPDT超导磁喷管外部磁场影响分析

由于传统提供附加磁场的液冷铜线圈存在体积大、质量大、电耗大等显著缺点，因此电流密度高、体积小、损耗低的高温超导（HTS）磁体在附加场磁等离子发动机（AF MPDT）上的应用受到了广泛的关注。然而由于超导材料的临界特性，HTS磁体容易受到外部磁场的影响而发生失超。文章通过对MPDT放电回路的简化，采用仿真和试验的方法来分析简化回路通电时激发的磁场，并研究其对外围HTS磁体的影响程度。仿真结果表明，MPDT放电室内部磁场以周向磁场为主，且由于阳极壁面电流对内部磁场的屏蔽作用，使得外部几乎没有磁场分布。试验结果和仿真也取得了良好的一致性，因此在设计超导磁喷管时几乎可以不考虑来自MPDT放电室磁场的影响。该研究为HTS磁体在AF MPDT上的应用提供了参考。

Analysis of external magnetic field of MPDT superconducting magnetic nozzle

The traditional liquid cooled copper coils which provide applied magnetic field have significant disadvantages such as large volume, big mass and high power dissipation. Therefore, high temperature superconducting (HTS) magnets have received widespread attention in the application of applied field magnetoplasmadynamic thruster (AF MPDT) because of their tiny volume, low power dissipation and high current density. Due to the critical characteristics of superconductor material, HTS magnets are susceptible to quenching due to the influence of external magnetic field. In this paper, by simplifying the discharge circuit of MPDT, simulation and experimental methods were used to analyze the magnetic field of discharge simulator, and to study the influence on the HTS magnet. The simulation results show that the magnetic field inside the MPDT discharge chamber is mainly composed of the circumferential direction, and due to the shielding effect of the anode current, there is almost no magnetic field distribution outside the discharge chamber. The experimental results also achieved good agreement with the simulation. Therefore, when designing a HTS magnetic nozzle, it is not necessary to consider the influence of the magnetic field from the discharge chamber. This research provides a reference for the application of the HTS magnet on the AF MPDT.