Tokamak Energy named magnet systems partner for the STEP prototype fusion plant

What happened

On 14 April 2026, at the Fusion Fest event in London, Tokamak Energy was confirmed as Magnet Systems Partner for STEP, the UK's prototype fusion power plant planned for West Burton in Nottinghamshire. The contract is worth £70 million and runs to March 2029, covering eight work packages spanning magnet design and integration, tokamak systems architecture and plasma integration, delivered alongside UK Fusion Energy (UKFE), the body running the programme.

The award was the larger part of roughly £100 million in STEP contracts announced in the same period. Dassault Systèmes took a £30 million contract to expand its 3DEXPERIENCE platform into the plant information management system for the project.

The selection followed a demonstration milestone: Tokamak Energy's Demo4 high-temperature superconducting (HTS) magnet system reached 11.8 tesla at cryogenic temperature with 7 million ampere turns — described by the company as the first world-level performance demonstration of an integrated HTS magnet system in full tokamak configuration.

The technology

Magnets are the defining engineering problem of magnetic-confinement fusion. A tokamak holds plasma at temperatures far beyond what any material can touch, using magnetic fields alone; the strength and reliability of those fields set the machine's performance envelope. HTS magnets matter because they can produce higher fields in more compact machines than conventional low-temperature superconductors, and they are the technology on which STEP's spherical tokamak design depends.

Demo4 was built to answer the question of whether HTS coils behave as required not in isolation but arranged as a complete tokamak magnet set — toroidal and poloidal coils interacting as they would around a real plasma vessel. The 11.8 tesla result in that full configuration is the evidence UKFE bought into.

Tokamak Energy brings manufacturing capacity as well as test results. The Oxfordshire company, based at Milton Park with more than 280 staff, operates the ST40 compact high-field spherical tokamak, which continues to be used under the contract, and delivers magnet work through its TE Magnetics division. In 2025 it acquired Ridgway Machines in Leicester to manufacture HTS systems at scale.

Why it matters for UK & Ireland

STEP is the UK's bet that it can move from fusion science to fusion engineering ahead of other programmes, with operations targeted for 2040 on the site of the former West Burton coal-fired power station, selected in October 2022. The choice of magnet partner is arguably the single most consequential supply-chain decision in the programme, and the government has made it domestically: a private UK company, its magnet factory in Leicester, its test machines in Oxfordshire.

That anchors a genuinely scarce capability in Britain. HTS tokamak magnets at this performance level exist in very few places worldwide, and the countries that can build them will hold a strong position in every fusion programme that follows. As Tokamak Energy chief executive Warrick Matthews said, "Confirming our position in the UK's world-leading fusion programme is a proud day for Tokamak Energy." UKFE's chief commercial officer Dan Bishop framed it as a delivery partnership rather than a conventional procurement.

For the East Midlands, the award adds substance to plans for West Burton beyond the plant itself, which include a skills centre and business park on the former coal site — a concrete example of energy-transition reuse of legacy generating land.

What to watch

This entry was verified against the company's own announcement and independent coverage from World Nuclear News; the core facts — £70 million, March 2029, eight work packages, 11.8 tesla, are consistent across both. The open questions are about execution. The contract runs three years; STEP operations are targeted for 2040, so this is early-stage design and integration work, not plant construction.

Watch for whether Demo4 performance translates into STEP-scale magnet specifications, how the Ridgway Machines facility scales HTS production, and whether follow-on packages after March 2029 stay with Tokamak Energy, the strongest signal of whether the UK intends to keep this capability sovereign through to an operating plant.