The archive · Space, Robots, Defence · Strategic decision · 2009–2026
Tokamak Energy bets compact HTS-magnet fusion; Demo4 first to hit power-plant fields
Oxford's Tokamak Energy bet high-temperature superconducting magnets make compact fusion viable; in Nov 2025 its Demo4 full magnet system reached 11.8 T.
Tokamak Energy
What the business is
Tokamak Energy builds spherical tokamak fusion machines and, via its TE Magnetics division, high-temperature superconducting (HTS) magnet systems for fusion and other high-field applications.
Starting capital：£100M ($125M) raise announced 2024-11-20, co-led by East X Ventures and Lingotto Investment Management, joined by Furukawa Electric, British Patient Capital, BW Group and Sabanci Climate Ventures.
How it started
Tokamak Energy spun out of the UK Atomic Energy Authority in 2009 near Oxford. Its bet was that high-temperature superconducting magnets would let a compact, privately built spherical tokamak confine plasma at fusion power-plant fields, avoiding the scale and cost of conventional fusion designs.
What happened
In November 2024 it raised £100M ($125M) co-led by East X Ventures and Lingotto Investment Management, with new investors including Furukawa Electric, British Patient Capital, BW Group and Sabanci Climate Ventures, and launched TE Magnetics to commercialize its magnet technology. In November 2025 its Demo4 rig - a complete tokamak-configuration set of HTS magnets with 14 toroidal and 2 poloidal field coils - produced 11.8 Tesla at -243 degrees Celsius and drove seven million ampere-turns through its central column. Coverage in Interesting Engineering and Energy Innovation Review called it a world first: fusion power-plant fields replicated in a full HTS magnet system, not just a single magnet.
No ending yet — it is still running.
Background
Tokamak Energy is an Oxford-area fusion company spun out of the UK Atomic Energy Authority in 2009. Its bet is that high-temperature superconducting (HTS) magnets make compact spherical tokamaks viable: stronger fields at higher operating temperatures than conventional superconductors shrink the machine and its cost, letting a private company chase power-plant fields that public megaprojects reach with enormous scale.
Instead of selling only a distant fusion future, the company created TE Magnetics to commercialize the magnets themselves. In November 2024 it raised £100M ($125M), co-led by East X Ventures and Lingotto Investment Management, with new strategic investors Furukawa Electric, British Patient Capital, BW Group and Sabanci Climate Ventures, earmarking part of the money for the magnet business.
On 2025-11-19 Tokamak Energy announced that Demo4, a complete set of HTS magnets in tokamak configuration (14 toroidal and 2 poloidal field coils), had reached 11.8 Tesla at -243 degrees Celsius and driven seven million ampere-turns through its central column. Coverage in Interesting Engineering and Energy Innovation Review described it as the first time fusion power-plant level fields had been produced by a full HTS magnet system, validating one technical path to grid fusion.
What has to be true
- HTS magnets produce far stronger fields at higher temperatures than conventional superconductors, shrinking fusion machines; HTS carries about 200x copper's current density.
- Demo4 de-risked the central bet by validating a complete tokamak-configuration magnet system at 11.8 T, not just single magnets, giving engineers data for power-plant designs.
- TE Magnetics turns a decades-away fusion mission into a current business, selling the same HTS technology to data centres, electric aviation and maglev markets.
- Strategic investors tied the bet to supply chain: Furukawa Electric, an HTS wire maker, joined the $125M round alongside East X Ventures and Lingotto.
What can be applied
Bet on a component you can sell before the whole system works: validating fusion magnets while commercializing them for other industries funds a decades-long mission.
Aftermath
As of the Demo4 announcement (2025-11-19), Tokamak Energy said further tests toward higher fields were ongoing with the next results expected in early 2026. TE Magnetics targets non-fusion uses of HTS - which carries roughly 200 times the current density of copper - in data centre power distribution, zero-emission flight and magnetic levitation. The National reported the company's goal of a commercially viable fusion power plant within about ten years. The cited sources report no acquisition or wind-down.
Sources
- World-first super magnet breakthrough key to commercial nuclear fusion
- Tokamak raises $125 million to commercialise fusion energy technology
- Tokamak Energy's Super Magnet Breakthrough Paves Way for Commercial Fusion Power
spotted an error? The archive wants to know.
Your turn
You just read one. Describe what you are building, and see who is betting on the same thing.
Free account · 3 free questions · no card