Enhancing the MAST Upgrade Fusion Device
The United Kingdom is in the midst of upgrading the MAST Upgrade fusion reactor, aiming to double its plasma heating capacity from 4.4 MW to 8.8 MW and raise the plasma core temperature to an extraordinary 60 million degrees Celsius. These improvements are taking place at the Culham campus, which also serves as the site for preparing equipment to build the prototype commercial fusion power plant known as STEP.
A new "double beam box" design will be installed on-site, outfitted with two injectors that direct high-energy neutral atoms into the plasma. MAST Upgrade is a compact spherical tokamak dedicated to exploring reactor physics. Its stainless steel 316L chamber weighs approximately 15 tons and holds a volume of 20 cubic meters. Additionally, a microwave system utilizing Bernstein electron waves is being integrated at Culham to support plasma heating and diagnostics.
Next Steps and Experimental Progress
Alongside the MAST Upgrade enhancements, electrical systems from the JET reactor—shut down in 2023—are being repurposed. Positive ion injectors are under development, and a cryopump is being installed inside the chamber to improve plasma control.
In August, MAST Upgrade concluded its fifth experimental campaign, executing over 1,100 plasma pulses. This campaign successfully set a new record for plasma pressure without any loss of control, marking a significant milestone in fusion research.
Installation of the remaining internal components is scheduled to be completed by late autumn 2027, with new experimental runs planned to begin in 2028.
“This equipment installation represents a major leap forward, as the doubled power enables the creation of extreme conditions never before achievable,” said Andrew Thornton.
Upgrading the MAST Upgrade facility is a crucial step for advancing fusion energy in the UK. Raising both the heating power and plasma temperature brings the country closer to realizing commercial fusion power plants, offering a promising source of clean energy for the future. The success of past experimental campaigns and continued refinement of the technology are vital for reaching these goals.
The collaboration between MAST Upgrade and the JET reactor highlights the importance of integrating new innovations into existing infrastructure to accelerate progress within fusion science.
As the UK pushes forward with its advancements in fusion technology, it is interesting to note that the United States is also making strides in nuclear innovation. Their plans for a cutting-edge molten chloride salt reactor aim for criticality by 2027, showcasing a global commitment to exploring new energy frontiers. These developments reflect a broader trend in the energy sector towards sustainable and innovative solutions.