Located at UKAEA’s Culham Campus, MAST (Mega Amp Spherical Tokamak) Upgrade is the UK’s flagship fusion machine. It creates plasmas reaching 30 million degrees Celsius. MAST Upgrade has three key aims:
- To investigate novel exhaust concepts
- To de-risk / advance the spherical tokamak design, as a future power plant
- To extend physics knowledge in support of the broader fusion programme
MAST Upgrade is studying some of the key physics challenges which remain. To do this, the MAST Upgrade tokamak builds on the original MAST machine which ran from 2000 to 2013. MAST was reengineered to create MAST Upgrade. This enabled higher performance, such as longer plasma pulses, increased heating power and a stronger magnetic field, plus an innovative new plasma exhaust system.
MAST Upgrade is keeping the UK at the forefront of global research in our quest for a sustainable and low carbon energy.
Plasma exhaust
One of the key challenges MAST Upgrade focuses on is understanding and reducing the heat from a super-hot plasma. The tokamak exhaust system is known as the ‘divertor’. It takes the particles and heat ejected from the plasma and directs it onto surfaces within the tokamak. To achieve commercial fusion power, we must solve the key issue of plasma exhaust.
There will be intense power loads in the large fusion machines in future power plants. This has the potential to damage the divertor components which would require replacement every few years. It would make it difficult for fusion to become an economically competitive energy source. The challenge is to develop a divertor which can reduce the power loads to a manageable level. This would be about the same as in a car engine. Experiments in MAST Upgrade are providing valuable information on how to cool the plasma enough, where it meets surfaces in the divertor, to ensure that any damage is minimal.
MAST Upgrade is unique. It is the first tokamak in the world to use a highly optimised Super-X divertor. This is a unique exhaust system which should mean divertor components last much longer. Previous experiments on MAST Upgrade using the Super-X divertor were successful. It reduced the heat load on the parts of the divertor by a factor of ten.
MAST Upgrade can also operate with a variety of other divertor configurations. This eables it to compare their effectiveness and inform design choices for future fusion machines.
Advancing the spherical tokamak design
MAST Upgrade continues UKAEA’s pioneering research into spherical tokamaks. The spherical tokamak design has benefits which mean it can achieve more efficient performance. This has excellent potential to build a more compact power plant. For example, the UK’s prototype fusion power plant – STEP (Spherical Tokamak for Energy Production).
A facility to extend physics knowledge in support of the broader fusion programme
Fusion scientists from around the UK and globally use MAST Upgrade to study plasma physics. Researchers from UKAEA and partner universities and other fusion laboratories use it to carry out a wide range of experiments. MAST Upgrade has excellent diagnostics and plasma viewing capabilities. This makes it one of the best tokamaks for novel experiments and allow it to capture extensive data.
MAST Upgrade is funded by the Department for Energy Security and Net Zero (DESNZ). It is part of the EUROfusion European Medium-Sized Tokamak programme.
MAST Upgrade’s latest scientific campaign
We recently completed the fifth scientific campaign on MAST Upgrade, marking another major milestone in the programme. This latest series of experiments brought together more than 200 researchers from over 40 institutions. They created more than 1,000 plasmas to help answer some of the biggest questions in fusion physics and help make fusion power a reality.
The team is now undertaking a programme of essential engineering work alongside exciting upgrades to the tokamak’s heating systems. This will further enhance MAST Upgrade’s capabilities and prepare the machine for its next phase of world-leading research.
Latest news
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Under Pressure: Record plasma for UK flagship machine
UKAEA has completed its fifth series of experiments on its MAST Upgrade fusion machine, overcoming plasma instability issues and pioneering novel techniques.
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UK flagship fusion machine’s next phase of cutting-edge research
UKAEA’s MAST Upgrade fusion machine’s fifth campaign will incorporate new enhancements to expand on plasma research, feeding directly into future fusion plant design
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UK scientists achieve breakthrough that brings fusion energy closer to reality
MAST Upgrade, the UK’s national fusion experiment, has demonstrated multiple world-first breakthroughs during its fourth scientific campaign.
