Fusion magnets set for extreme testing in US

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.”