Europe · UK · Founded 2009
Tokamak Energy
Magnetic confinement — spherical tokamak
Magnetic
Deuterium-Tritium
≈ £250M cumulative
Demonstration plant ~2030; commercial 2030s
Investor brief
Spherical tokamaks and the UK's de facto HTS magnet supplier
Executive Summary
Tokamak Energy is the UK's spherical-tokamak pioneer and the de facto HTS magnet supplier to the UK fusion programme. Its ST40 reached 100 million °C ion temperature in 2022; in 2024 it tested a 26.2 T HTS magnet at CERN — among the highest fields ever reached by an HTS demountable magnet. In 2025 it was named magnet systems partner for the UK STEP programme.
Strategic Thesis
Spherical geometry yields the highest β (plasma pressure / magnetic pressure) of any tokamak. Combined with HTS, this enables a much smaller, cheaper compact plant.
The Problem
Global electricity demand is entering an unprecedented growth phase driven by AI infrastructure, data centers, transport electrification, industrial decarbonization, water desalination, and advanced manufacturing. Solar suffers intermittency, wind capacity-factor variability, natural gas carbon emissions, conventional nuclear cost and deployment speed, and batteries energy-density and duration limits. The world requires a new source of clean, dispatchable baseload energy. Fusion represents the ultimate energy source — the challenge is making it commercially practical.
Compact Spherical Tokamak + HTS Magnets
Spherical tokamaks compress the donut into nearly a sphere, achieving the highest plasma β of any tokamak topology. Combined with HTS magnets, this enables a much smaller, cheaper compact plant.
ST40 — Plasma Performance Record
First privately-funded device to reach 100 million °C ion temperature.
ST80-HTS Demonstrator
Next-generation device validating HTS magnets in the spherical geometry.
HTS Magnet Business
Tokamak Energy's magnet division supplies the UK STEP programme and is positioning as a global HTS supplier.
Fuel Strategy
Deuterium-Tritium
Standard D-T fuel cycle.
Product Platform
ST40
Current research device with record plasma performance.
ST80-HTS
Next-generation HTS spherical tokamak demonstrator.
HTS Magnet Systems
Commercial HTS magnets for STEP and the broader fusion industry.
Energy Conversion
Thermal (Rankine/Brayton)
Neutronic (D-T)
33–40% electrical
Deuterium-tritium fusion releases ~80% of its energy as 14.1 MeV neutrons, which deposit their kinetic energy in a surrounding blanket. The heat drives a conventional steam (Rankine) or supercritical-CO₂ (Brayton) turbine.
Conversion chain
- 1D-T plasma
- 214.1 MeV neutrons (80%) + 3.5 MeV alpha (20%)
- 3Neutrons → lithium-bearing blanket (heat + tritium breeding)
- 4Heat → steam/CO₂ turbine → electricity
The most thoroughly understood fusion fuel cycle, highest cross-section at achievable temperatures, and proven back-end engineering (steam turbines are 19th-century technology). Trade-offs: neutron-induced materials damage, tritium handling, ~33–40% Carnot-limited efficiency.
Economic Vision
Twin-track business model: a commercial HTS magnet business generating revenue today, while the spherical-tokamak power-plant program matures over the 2030s.
Vision
Spherical tokamaks as the most compact magnetic-confinement pathway to commercial fusion.
Mission
Deliver compact spherical-tokamak fusion power and supply the magnets the rest of the industry needs.
Engineering Bottlenecks
- Inboard centre-post neutron shielding (no room for thick blanket)
- Disruption mitigation in compact ST geometry
Milestone Timeline
2022
ST40 reached 100M °C ion temperature
2024
26.2 T HTS magnet test at CERN
2025
Named magnet systems partner for UK STEP
The description above reflects Tokamak Energy's publicly stated technology goals, roadmap and architecture. Many elements — particularly net-energy gain at scale, advanced fuel cycles, and grid-relevant economics — remain ambitious objectives that have not yet been demonstrated commercially anywhere in the fusion industry. Forward-looking statements should be treated as engineering targets, not certainties.
Tokamak Energy alerts
Get milestone alerts for this company
Weekly email digest of Tokamak Energy's funding, technical milestones and regulatory filings.
Joining 2,400+ fusion insiders · No spam · Unsubscribe in one click.
Citations & Sources
Academic & financial rigor- [01]
ST40 achieves 100 million °C
Tokamak Energy · 2022
- [02]
26.2T HTS magnet at CERN
Tokamak Energy · 2024
- [03]
The Global Fusion Industry in 2025
Fusion Industry Association · Jul 2025
- [04]
Company disclosures and press releases
Tokamak Energy
- [05]
Peer-reviewed plasma physics literature
Journal of Plasma Physics / Nuclear Fusion