Tokamak Energy wins £70m STEP contract to lead UK Fusion magnet development

Tokamak Energy’s Demo4 HTS magnet system delivered world-first field strength performance in a full tokamak configuration, securing the company’s place as STEP Fusion’s Magnet Systems Partner

(Images courtesy of Tokamak Energy)

Tokamak Energy has been named Magnet Systems Partner for the UK’s STEP Fusion programme, with UK Fusion Energy (UKFE) awarding a £70 million contract running to March 2029. The appointment, announced at Fusion Fest in London on the 14th April, puts the Oxfordshire-based company’s HTS magnet systems at the core of the most ambitious domestic fusion project ever undertaken. For the programme, it marks a decisive move from concept into delivery.

HTS magnet systems at the heart of STEP delivery

Tokamak Energy will act as systems partner across eight work packages covering magnets, tokamak systems, and plasma integration. Delivery runs through TE Magnetics, the company’s dedicated high-temperature superconducting division, which covers design, manufacturing, and test capability for advanced HTS systems. UKFE selected Tokamak Energy as the leading UK-based manufacturing expert with the specialist capability for this work.

The contract also provides continued access to the company’s ST40, a compact high-field spherical tokamak that has recently posted record levels of plasma current and energy performance. Under the partnership, UKFE will use ST40 and associated HTS magnet platforms to test magnetic configuration, coil forces, plasma stability, and quench behaviour under realistic conditions. This direct access to operational hardware accelerates validation cycles ahead of STEP’s later design phases.

Tokamak Energy is the UK’s only specialist manufacturer of high-field HTS magnet technology. That status makes the contract as much a sovereign capability decision as a technical one, securing domestic expertise and reducing reliance on global supply chains for a programme where field strength and plasma confinement performance are non-negotiable.

Demo4 performance sets the benchmark for tokamak scaling

Tokamak Energy’s Demo4 HTS magnet system is central to the technical credibility the company brings to the role. The system achieved 11.8 Tesla at cryogenic temperatures with seven million ampere turns, reproducing fusion-relevant magnetic environments at full tokamak system level. UKFE will be able to draw directly on that verified field strength data as the STEP engineering programme advances.

The 2025 acquisition of Leicester-based Ridgway Machines strengthens the industrial scaling argument further. Ridgway is the leading provider of bespoke equipment for superconducting magnets and cable production, and its integration gives Tokamak Energy end-to-end capability for delivering high-quality HTS products at scale. That vertical reach matters for a programme that must move from engineering iteration into supply chain delivery.

STEP itself has transitioned from concept into delivery following completion of the design concept phase and Government approval for whole plant development at West Burton, Nottinghamshire. CEO Warrick Matthews described HTS magnets as a transformative technology essential for delivering energy-producing fusion devices like STEP, adding that the company’s experience operating two advanced fusion machines would prove valuable as the programme scales toward a low-carbon, secure energy future.

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