What is MAST Upgrade?
Our brief guide to the Mega Amp Spherical Tokamak Upgrade national fusion machine at UKAEA.
The Mega Amp Spherical Tokamak (MAST) Upgrade is the national fusion machine running experiments that push the boundaries of spherical tokamak science, helping to make fusion happen faster.
MAST Upgrade is teaching us about 3 key aspects of fusion:
- exhausts and how we manage the heat and gases coming from the plasma
- spherical tokamak design and how we can make fusion power plants more efficient
- physics knowledge, such as how the shape or temperature of the plasma affects its power
MAST Upgrade is taking huge steps for fusion. In 2025, experiments used a 3D magnetic field to stabilise plasma in a spherical tokamak for the first time. It also has the world’s first Super-X divertor, cooling the super hot plasma to protect vital parts of the machine.
Scientists from all over the world come to use MAST Upgrade, collaborating with the team at UKAEA to bring commercial fusion closer with each experiment.
Fusion energy
We are turning the process that powers the Sun into a low carbon, safe and sustainable part of the world’s future energy supply.