Commonwealth Fusion Systems supplies superconducting magnets to university

Private fusion company CFS's primary mission remains delivering fusion devices of its own design, including the SPARC tokamak now under construction. It says the SPARC prototype fusion machine will pave the way for a first commercially viable fusion power plant called ARC. SPARC is described as a compact, high-field, net fusion energy device which would be the size of existing mid-sized fusion devices, but with a much stronger magnetic field. It is predicted to produce 50-100 MW of fusion power, achieving fusion gain greater than 10.

CFS - a Massachusetts Institute of Technology spinout company - said the technology that enables SPARC's powerful magnets can also significantly improve other applications in fusion and beyond. A number of other companies have approached CFS given its world-class capabilities in designing, developing, and manufacturing high-temperature superconducting (HTS) magnets for other markets.

"We have the capability to build some of the highest power magnets in the world," said CFS Chief Commercial Officer Rick Needham. "Designing and building these magnets for other applications is a business opportunity that could be in the billions of dollars."

Starting in 2019, the University of Wisconsin sought CFS help to deliver the magnet technology for its WHAM (short for Wisconsin HTS Axisymmetric Mirror) experiment. Together they developed magnet concepts optimised for a new generation of mirrors. This led to a system of two identical flat and thin magnets that can reach a magnetic field of 17 tesla in the bore and over 20T on the magnets themselves - about 400,000 times stronger than Earth's magnetic field. Funding from the Advanced Research Projects Agency–Energy (ARPA-E) aided that effort.

CFS designed and built the superconducting magnets for WHAM at its headquarters in Devens, Massachusetts. The proprietary magnet technology, based on thin and flexible HTS tape, accommodates very high electrical currents that generate very high magnetic fields. The magnets are self-contained systems that have all the needed functions including cryogenic refrigeration, vacuum pumping, control, and monitoring, all designed, constructed, and supplied by CFS as a turnkey system.

WHAM is expected to create the world's highest magnetic field for a mirror plasma. The experiment will help validate computer models for designing more powerful magnetic mirror devices that one day could become fusion power plants for some applications.