13.7 Tesla. Around 10,000 hours of operation. One complete fusion magnet system. After a 14-month campaign, our world-leading Demo4 high temperature #superconducting (HTS) magnet system has successfully completed testing. Developed and operated by our TE Magnetics team, Demo4 brought together 44 #HTS coils in a fusion-relevant spherical tokamak configuration with integrated power, cryogenic, control and protection systems. During the campaign, it: ✅ Completed ~10,000 hours of system operation in various states of energisation, including extended periods at high field ✅ Reached a peak magnetic field of 13.7 Tesla ✅ Ran toroidal field (TF) coils at 5,600 A ✅ Tested performance from 77 Kelvin down to 17 K ✅ Operated under 150 MPa transverse compressive pressure ✅ Completed multiple forced discharges at up to 12.5 T and high current ✅ Proved the reliability of more than 90 HTS joints But the campaign was about more than reaching headline numbers. It validated our models and gave us extensive data and experience in HTS system performance and operation. That learning is already informing our next generation of HTS systems for #fusion and beyond, including our work as Magnet Systems Partner on the UK Government's @STEPtoFusion programme. The results are being presented this week at the Applied Superconductivity Conference #ASC in Pittsburgh by Principal HTS Engineer Bas van Nugteren. "Demo4 is a major technical and commercial milestone. It proves we can design, build and operate complete HTS magnet systems, and underpins our ambition to become the go-to HTS magnet provider for the fusion industry – building on our role as STEP’s Magnet Systems Partner and our place in the UK Infinity Fusion Consortium. The system endurance testing results provide excellent data to show the robustness of our HTS designs, which is relevant across all industrial applications for magnets and power systems.” Warrick Matthews, CEO, Tokamak Energy “HTS magnet design is key to the performance and affordability of a fusion power plant. Demo4 proves our integrated magnet system can perform under demanding fusion-relevant configurations and we’re already putting this learning to work with UK Fusion Energy on the national STEP programme.” Liam Brennan, Director of TE Magnetics A huge achievement by everyone involved in designing, building and operating Demo4 throughout the campaign 👏 Read the full release here: tokamakenergy.com/2026/09/09… #FusionEnergy #Superconductors #HTS #Engineering #ASC2026