World First! UK-based TE's Demo4 Magnet Successfully Achieves Fusion Power Plant-Grade High Field Strength
2025-11-24
On November 19, 2025, Tokamak Energy (TE) announced that its Demo4 high-temperature superconducting (HTS) magnet successfully achieved a field strength of 11.8 T at -243°C (30 K), with a centre column current reaching 7 million ampere turns. This is the first time that HTS fusion magnet technology has achieved a breakthrough under magnetic field conditions required for future fusion power plants. Shanghai Superconductor has collaborated deeply with TE, supplying REBCO tapes in batches for the project to be used in the development of high-field magnets and superconducting controlled nuclear fusion.
Demo4 verified that HTS magnets can generate the high-strength magnetic fields required for fusion power generation, providing a key technical solution for achieving clean, unlimited, and safe fusion energy grid integration. The project represents over a decade of HTS innovation at TE, providing uniquely valuable engineering insight and data to inform power plant designs of the future.
The successful testing of Demo4 further advances the development of HTS controlled fusion technology.