As part of the quest to build a commercially viable fusion reactor, a team at Commonwealth Fusion Systems has developed a new type of high-power magnet, made using multiple layers of tape containing barium copper oxide, which, when cooled to minus 253 C, becomes superconducting. This is very cold, of course, but in the world of superconductivity, it’s practically warm. The magnetic tape has taken decades to develop, and means considerably less complex refrigeration is required. An experimental fusion reactor is to be built in Massachusetts that uses 18 10-ton versions of the new magnets arranged into a tokamak, a torus-shaped ring that creates a magnetic field to contain the plasma as it is heated to tens of millions of degrees.
–CL