Progress Toward a 10-kA Superconducting Power Supply for Levitated Dipole Reactors

OpenStar Technologies is a private fusion company in New Zealand, developing a fusion reactor based on the levitated dipole. The levitated dipole has a stable magnetic configuration, which provides the basis for the design of a fusion concept. Levitated dipole-based fusion reactors will require large scale high-field high temperature superconductor (HTS) magnets operating with consistent “quasi-persistent” current while levitating. Quasi-persistent currents in levitating magnets can only be supplied by on-board power supplies that continuously replenish the energy lost from magnet operation. OpenStar has designed, built, and validated an HTS rectifier which to date has charged a 0.53 H non-insulated HTS magnet to 824 A. The initial charging of this magnet to 180 kJ over 60 hours demonstrates the first integration of a large scale HTS magnet with an embedded HTS rectifier. In October 2024, this enabled OpenStar to reach the milestone of first plasma.