Engineers at the UK Atomic Energy Authority (UKAEA) have manoeuvred a 12-tonne component into position for MAST Upgrade, the UK's flagship fusion machine at the Culham Campus, the authority announced on 3 November 2026. The double beam box has a double-decker layout designed to house two additional neutral beam injectors, which fire high-energy neutral atoms into the plasma.

According to UKAEA, the new box will raise neutral beam heating power from 4.4 megawatts to 8.8 MW. Plasma temperatures are expected to double from 30 million to 60 million degrees Celsius, allowing researchers to study the physics and technology needed for future fusion power plants, including the UK's STEP prototype. Andrew Thornton, Head of MAST Upgrade Operations, said the work would let teams study the stability of higher-pressure plasmas and how the machine's exhaust system handles them.

The lift is part of wider engineering work, including a new electron Bernstein wave microwave heating system, power supply equipment repurposed from the Joint European Torus, and a cryopump due to be installed inside the vessel. The completed vessel, including its lid, will weigh around 15 tonnes. UKAEA expects major hardware to be fitted by the end of autumn 2027, with experiments due to begin in 2028.