Technical report | Strong Magnetic Field Characterisation

Abstract

 Three magnetic field sources were characterised through a combination of selected measurement and subsequent modelling. Detailed spatial and temporal field distributions were developed as a consequence. The results provided a basis from which to develop hardware for use in pulsed-power experiments.

Executive Summary

There was a requirement to develop reasonably strong (~1 T), sufficiently long lived (~100 µs) magnetic fields for experiments investigating interactions between hot gases from a detonation and the magnetic field. The present investigation explored the utility of a rare earth permanent magnet and electromagnets as sources. Two electromagnet sources were constructed (a single coil and a Helmholtz like pair of coils). These coils were driven by a pulsed-power system to generate the fields. All the sources were characterised through a series of measurements and modelling. The goal was to develop a sufficiently representative spatial and temporal model that could be used as input to magnetohydrodynamic modelling. A model of the magnet was developed and this compared well with data within a small measurement region. The coil models also proved reasonable representations. It was determined that a ~1 T field could be constructed near the single coil electromagnet for approximately 78 µs. A smaller field of ~ 0. 4 T was achieved with the Helmholtz like pair. The model also showed that our system was probably at the limit of our capability for producing intense fields, particularly for the Helmholtz like pair. The spatial distribution of the fields was predicted. Temporal distributions were also generated for the coils. Options for further investigation were provided.