- UK’s MAST Upgrade machine’s fifth campaign underway, laying foundations for fusion power plant development
- Campaign builds on world-first achievements of recent research
- 200 international researchers to conduct 950 plasma ‘pulses’ over six months
- Research directly supports design of STEP Fusion power plant and UK’s clean energy mission
The UK Atomic Energy Authority’s (UKAEA) flagship fusion machine has launched its fifth scientific campaign to begin fusion experiments that will help develop the UK’s first fusion power plant.
The Mega Amp Spherical Tokamak (MAST) Upgrade’s latest campaign will run for six months with more than 200 researchers – from more than 40 global research institutions – conducting 950 plasma ‘pulses’, advancing our knowledge and understanding of spherical tokamak plasmas. A pulse refers to the duration a plasma is confined within a fusion machine’s inner vessel.
MAST Upgrade will receive significant enhancements to expand its capabilities and support the design of STEP Fusion, a programme to build the UK’s first prototype fusion power plant. A new Electron Bernstein Wave heating system – the same technology planned for STEP – will be installed in 2026, allowing scientists to replicate STEP-like methods for heating the plasma. Two additional neutral beam injectors will be added in 2026–2027, doubling the machine’s heating power. The coupling of power (EBW and Neutral Beams) will be the first time these heating systems have worked together in a spherical tokamak.
This campaign will allow us to build on the world-first achievements from the previous scientific campaign. We’ve had significant interest globally for experiments on MAST Upgrade illustrating the fantastic collaboration effort in fusion research. Over the coming months, we hope to push further the boundaries of what’s possible in spherical tokamak science.
James Harrison, Head of MAST Upgrade Science
The upcoming cutting-edge upgrades will allow us to generate hotter, higher performance plasmas that move us closer to those in future fusion power plant more than ever before. We look forward to the new heating systems being operational to explore plasma science in more depth with this type of fusion machine.
Andrew Thornton, Head of MAST Upgrade Operations
The fifth campaign will focus on four key areas critical to the development of future fusion power plants such as STEP:
- Understanding high pressure fusion plasma, helping to improve predictions for future fusion power plants, like STEP Fusion, by testing models in MAST Upgrade.
- Optimising energy control and stability, combining techniques to prevent plasma instabilities with advanced exhaust systems like the Super-X divertor, for the first time, to achieve more efficient plasma performance.
- Improving divertor design by developing the shape and magnetic configuration of divertors to better handle the excess energy and reduce their size, helping to make future fusion plants smaller and more cost effective.
- Testing tools that predict plasma behaviour using computer models to forecast how plasma will behave – specifically looking at heating, stability and plasma exhaust. This reduces uncertainties when designing and operating future fusion machines like STEP and ITER.
This fifth round of experiments will build on the world-first achievements of MAST Upgrade’s fourth campaign, where scientists successfully suppressed plasma instabilities in a spherical tokamak for the first time. The campaign also set a record for power injected into MAST Upgrade’s plasma at 3.8 MW and demonstrated world-first independent control of the plasma exhaust in the upper and lower divertors.
The response to the fourth campaign – with 125 research proposals submitted – demonstrates global confidence in MAST Upgrade’s unique capabilities and its role in shaping the future of fusion energy.
The cutting-edge research carried out by the MAST Upgrade team is paving the way for fusion to provide abundant, clean energy for future generations.