A portable magnetic field of > 3 T generated by the flux jump assisted, pulsed field magnetisation of bulk superconductors

TL;DR

This study demonstrates that flux jump-assisted pulsed field magnetisation can generate over 3 Tesla in bulk superconductors, enabling portable, high-field magnets at relatively low temperatures.

Contribution

It introduces a practical method for achieving high magnetic fields in bulk superconductors using flux jumps during pulsed magnetisation, with a portable system operating at 50-60 K.

Findings

Achieved >3 T trapped field in GdBaCuO bulk superconductor

Flux jumps enable full magnetization without extremely high applied fields

System operates effectively at 50-60 K

Abstract

A trapped magnetic field of greater than 3 T has been achieved in a single grain GdBa2Cu3O7-{\delta} (GdBaCuO) bulk superconductor of diameter 30 mm by employing pulsed field magnetisation (PFM). The magnet system is portable and operates at temperatures between 50 K and 60 K. Flux jump behaviour was observed consistently during magnetisation when the applied pulsed field, Ba, exceeded a critical value (e.g. 3.78 T at 60 K). A sharp dBa/dt is essential to this phenomenon. This flux jump behaviour enables the magnetic flux to penetrate fully to the centre of the bulk superconductor, resulting in full magnetization of the sample without requiring an applied field as large as that predicted by the Bean model. We show that this flux jump behaviour can occur over a wide range of fields and temperatures, and that it can be exploited in a practical quasi-permanent magnet system.