Speaker
Description
Flux pumps are devices able to energise superconducting magnets with no conductor crossing the cryostat wall: a time-varying field and a region of controllable resistance drive DC into a closed loop.After a brief account of how flux pumps developed, a review of the mechanisms available in HTS and the resulting taxonomy are presented: rotating and linear travelling-wave flux pumps, transformer–rectifier flux pumps with their switches, and self-switching bridges, with the trade-offs that make a flux pump something designed around its magnet. A brief energy and efficiency assessment shows that, although their instantaneous efficiency is modest, flux pumps run intermittently, so what counts is the energy consumed over the magnet’s whole duty cycle. Finally, three fields of application are examined: fusion toroidal-field coils and stellarator coils, magnetic shielding and electric propulsion for space applications, and magnetic resonance imaging.
