Devon-based Rockwood Composites has used composites to assemble the central core of Tokamak Energy’s ST40, which is the first world-class tokamak-controlled nuclear-fusion device to be designed, built and operated by a private company (www.rockwoodcomposites.com).

It is designed to show that fusion temperatures — 100 million °C — are possible in compact cost-effective devices. This has the potential to allow fusion power to be developed for commercial deployment in years, rather than decades.

Constructing the core involved the very precise application of a glass-fibre/ Kapton /glass-fibre insulation layer to each of the core elements.

The whole assembly was then bonded together, with precise control of the bond line thickness.

The Newton Abbot-based composites specialist developed this project from scratch, as no off-the-shelf solution was available.

It also supplied the entire cryogenic suspension system, comprising a large number of bespoke carbon-fibre bands. The technology is also being used in ITER, the world’s largest fusion experiment (in France, involving engineers and scientists from 35 countries).

Mark Crouchen, managing director of Rockwood Composites, said: “Fusion devices are built to create one of the most extreme environments you can get. The properties of composites are instrumental in enabling the ST40 to achieve temperatures that are hotter than the centre of the sun.

“This was a technical challenge that we relished engaging with; we knew we had the knowledge, materials and processing expertise to provide a technical and elegant solution. We’re now working with Tokamak Energy
on the next stage of development.”

Oxfordshire-based Tokamak Energy grew out of the Culham Centre for Fusion Energy and was established in 2009 to design and develop compact fusion power plants. Its aim is to put fusion power into the grid by 2030.