Fusion magnets set for extreme testing in US

Tokamak Energy’s magnet technology is set to be exposed to extreme conditions to test lifetime fusion power plant performance in a US Department of Energy laboratory.

Max Rowland, 28, pictured with the equipment in the attached image, will go to Albuquerque for six months to oversee the project
Max Rowland, 28, pictured with the equipment in the attached image, will go to Albuquerque for six months to oversee the project - Tokamak Energy

Creating fusion energy requires strong magnetic fields to confine and control hydrogen fuel, which becomes a plasma several times hotter than the Sun inside a tokamak.

Most radiation from high-energy plasma neutrons will be absorbed by the tokamak’s shielding, but the magnets must be able to withstand secondary gamma rays to maintain efficient power plant operations. 

Tokamak Energy built and commissioned its specialist gamma radiation cryostat system – a vacuum device that provides thermal insulation for the magnets – at its Oxfordshire headquarters.

The bespoke test system will now be disassembled, shipped, and rebuilt at the Gamma Irradiation Facility (GIF) based at Sandia National Laboratories in Albuquerque.

According to Tokamak Energy, it is one of the few places globally that is capable of housing the system while exposing the company’s high temperature superconducting (HTS) magnets to a power plant representative dose rates – sufficient in intensity and energy – of gamma radiation.

In a statement, Dr Rod Bateman, HTS Magnet development manager at Tokamak Energy, said: “Our pioneering magnet technology must withstand extreme conditions to keep fusion power plants running in the future. The specialist Sandia Laboratory is ideally configured to test magnet durability and performance when exposed to gamma radiation. It is essential to push the boundaries now as we scale up our operations towards commercial fusion.”

Research and analysis on sets of individual magnets will run for six months at the New Mexico facility, which can do a 60-year lifetime test in two weeks.

Don Hanson, GIF Facility supervisor at Sandia National Laboratory, said: “The GIF is a unique facility that can provide high doses of gamma radiation to large test objects. We look forward to working with Tokamak Energy to advance fusion technologies.”

Tokamak Energy has been a pioneer in recognising the opportunity to apply and develop HTS technology for fusion energy. In February, the company completed building a world-first set of magnet coils using 38km of HTS tape, which carries currents with zero electrical resistance and requires five times less cooling power than traditional materials.