The Wisconsin HTS Axisymmetric Mirror, or WHAM, is a magnetic mirror-style fusion device that uses innovative high-temperature superconducting (HTS) magnets to contain plasma better than previous versions.

WHAM was initially developed in 2020 through a $10M grant awarded to UW– Madison, MIT, and Commonwealth Fusion Systems (CFS). After the incredible milestone of initiating first plasma in July 2024, WHAM transitioned into scientific operational phase. It operates today as a public-private partnership with Realta Fusion, Inc.—a UW–Madison spinoff company based in Stoughton, Wisconsin.