Tokamak Energy validates 24 T REBCO magnet test at Milton Park
Demo magnet exceeds previous HTS field record by 4 T, with implications for compact spherical tokamaks.
Tokamak Energy announced validation of a 24-tesla peak field measurement on its Demo4 high-temperature superconducting magnet, exceeding the previous HTS field record by 4 tesla. The test, conducted at the company's Milton Park facility, used a fully cryogenic load assembly cooled to 20 K with helium gas.
Higher field strength permits more compact tokamak geometries — central to Tokamak Energy's spherical tokamak design thesis. The company is targeting first plasma on its ST80-HTS demonstrator in 2027, with a pilot plant follow-on by 2030.
CTO Otto Asunta said quench-protection thresholds were never tripped during the run, an important reliability marker for any HTS magnet program. REBCO tape supply — historically a bottleneck — has stabilized, with spot pricing at $11.40 per kA·m, down 2.6% week-over-week.
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