Abstract Body

Operating superconducting magnets in space presents unique challenges in cooling and charging within constrained energy and thermal budgets. Construction of a flight model HTS magnet is well advanced for delivery to the International Space Station. The magnet will operate on the Nanoracks External Platform (NREP) of the Japanese experiment module Exposed Facility (JEM-EF). The magnet consists of four double-pancake HTS REBCO coils with a warm bore of 52 mm. It is intended to approximate the magnet design suitable for Applied-Field magneto plasma dynamic (AF-MPD) ion thruster systems. We have operated the magnet at approximately 0.9 T during laboratory testing at 75 K. Current to the magnet of up to 30 A is supplied by a flux pump which minimizes the total thermal load. The magnet has achieved the same field pre and post vibration testing giving us confidence launch vibrations will not induce degradation. The experiment will incorporate two TimePix radiation sensors to measure the influence of strong magnetic fields on charged radiation incident on the space station.

This mission is part of a larger development program on Applied Field – Magneto-plasma-dynamic (AF-MPD) ion thrusters. We will show some early laboratory results from a larger bore and higher field magnet coupled to an in-house designed AF-MPD thruster demonstrating the advantages of higher fields in increased thruster efficiency and thrust density.

Acknowledgment

This work was funded by the New Zealand Ministry of Business, Innovation and Employment contract numbers RTVU2003 and RTVU1916.

Figure 1. Applied field magneto-plasma-dynamic thruster in operation.

Keywords: HTS magnet, applied-field MPD, ion thruster, space