Significant Advancements in Fusion Technology at UKAEA
Engineers at the UK Atomic Energy Authority (UKAEA) have reached a significant technological milestone by successfully positioning a substantial 12-tonne component for the MAST Upgrade, the UK’s premier fusion machine, located at the Culham Campus. This achievement marks an important step in the ongoing exploration of fusion energy.
The newly installed double beam box is ingeniously designed with a double-decker configuration intended to accommodate two neutral beam injectors (NBIs). These injectors are crucial to fusion research, as they propel high-energy neutral atoms into the plasma, effectively elevating its temperature to surpass 30 million degrees Celsius.
With the addition of two extra injectors, the updated double beam box will enhance MAST Upgrade’s neutral beam heating capability, increasing the total power from 4.4 megawatts (MW) to an impressive 8.8 MW. This enhancement is expected to significantly raise plasma temperatures, potentially doubling them from 30 million to 60 million degrees Celsius, thereby allowing researchers to examine the technologies and physics essential for the development of future fusion power plants, including the UK’s prototype fusion power plant, STEP.
Exploring New Plasma Conditions
Andrew Thornton, Head of MAST Upgrade Operations at UKAEA, remarked on the importance of this advancement: “The lift of the double beam box is a huge step forward for MAST Upgrade. By doubling our heating power, we will explore plasma conditions we simply couldn’t reach before. We will be able to study the stability of higher-pressure plasmas while testing how the MAST Upgrade exhaust system copes with these hotter, higher-performance plasmas.”
Thornton emphasised that addressing these critical issues is vital for the success of STEP and other future fusion power facilities. He also highlighted the accomplishment as a testament to the engineering prowess and collaborative efforts across UKAEA’s science and engineering teams.
Ongoing Engineering Enhancements
The lifting of the double beam box is part of a broader array of engineering projects currently in progress for MAST Upgrade. These include the installation of a new electron Bernstein wave (EBW) microwave heating system, as well as various other upgrades:
- The transfer and repurposing of power supply equipment from the Joint European Torus (JET).
- The fabrication and installation of the beam line module, which will facilitate the formation and injection of the neutral beam into the plasma.
- The manufacture and assembly of a cryopump, which will soon be installed within the double beam box vessel to regulate pressure.
- The installation of positive ion neutral injectors (PINIs).
Specifications of the Double Beam Box Vessel
When completed, the double beam box vessel, including its lid, will weigh approximately 15 tonnes, which is roughly equivalent to the weight of two and a half African elephants. It boasts a volume of 20 cubic metres, akin to that of 130 bathtubs, and is constructed from 316L stainless steel. This particular grade is renowned for its strength, durability, and resistance to corrosion, making it suitable for use in offshore structures and medical implants. Additionally, its excellent vacuum compatibility is essential for maintaining the ultra-high vacuum conditions necessary within the vessel.
All major hardware components are anticipated to be manufactured and installed inside the double beam box vessel by the end of autumn 2027. Following this, the vacuum-tight vessel will be commissioned for scientific experiments set to commence in 2028.