Scientists at the UK Atomic Energy Authority say experiments at the MAST Upgrade fusion facility in Oxfordshire have reduced key plasma instabilities that could otherwise hinder commercial fusion power. The work matters because sudden edge bursts can damage a reactor’s internal components and undermine the stable, long-duration operation needed for a power plant.

During experiments in 2025 and 2026, the team produced more than 1,100 fusion plasmas and reported MAST Upgrade’s highest stable plasma pressure. They tested several approaches, including magnetic perturbations and operating modes designed to release excess pressure gradually, as well as improved methods for monitoring plasma position. Further upgrades this year will double heating capacity and add 1.6 MW from an Electron Bernstein Wave system, ahead of another experiment series planned for 2028.