Thanks to the progress in developing High-Tc Superconducting (HTS) wires and tapes, HTS magnets have shown superior performance over their LTS counterparts in terms of high operating field, high engineering current density, and wide operating temperature range. Traditionally, HTS magnets operate in series connected mode in which all coils transport the same current. Due to the fact that HTS wires have a very strong field and field angle dependence of critical current density, the operating current is limited by end portions of the magnet. Although optimized magnet designs such as multi-width coils have been proposed, the engineering current density is far from being maximized.
In this work, we propose a novel HTS magnet form with all coils operating in parallel. Large transport current is generated by a flux pump and will auto-distribute into individual coils thus making each coil working close to its critical current. We will show the ultra-compact design concept, development procedures, and some preliminary test result. It is expected that this work could provide some new perspective in developing ultra-high field HTS magnets.

Keywords: HTS magnet, Flux pump, parallel operation, ultra-high current