Analysis of external magnetic field of MPDT superconducting magnetic nozzle

YAO  Lu, YANG  Wenjiang, WANG  Baojun, TANG  Haibin

1. School of Astronautics,Beihang University，Beijing 100191, China
• Received:2018-01-24 Revised:2018-06-06 Online:2018-10-25 Published:2018-08-29

Abstract: 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.