03.04.2024
CFS-MIT High-Field Magnet Technology for Commercial Fusion Experimentally Validated
MIT News
Todays most mature approach to commercial fusion power uses magnetic fields to contain a high-temperature plasma inside a fusion device called a tokamak. In 2015, researchers at MIT published a
paper predicting that tokamaks can be made smaller, easier to build, and more cost effective through the use of higher magnetic fields. However, at the time of that publication, the magnetic technology required to produce those fields had not been demonstrated.
Now, a series of
six peer-reviewed papers published in the journal
IEEE Transactions on Applied Superconductivity have demonstrated the required magnet technology, marking a pivotal moment in the high-field pathway to commercial fusion. These papers describe work that culminated in a
2021 test of the worlds strongest high-temperature superconducting (HTS) magnet for fusion, carried out by MITs Plasma Science and Fusion Center (PSFC) in collaboration with Commonwealth Fusion Systems (CFS). The magnet, called the Toroidal Field Model Coil or TFMC, was able to achieve a field of 20 T and a stored energy of 110 MJ, approaching the performance metrics required for the
SPARC net-energy tokamak currently under construction outside of Boston.
Crucially, the magnet exceeded the mechanical loading required by SPARCs magnets, directly addressing a key risk category. To extract the maximum information on its physics and engineering constraints, the magnet was then destructively tested, confirming predictive models and increasing confidence around its operational capabilities in a fusion power plant.
The lessons learned from these tests have informed the design, manufacturing, and operation of SPARCs full-scale TF magnets, which are currently being produced by CFS on a newly constructed high-throughput manufacturing line. This same magnet and manufacturing technology will be used for ARC, a commercial power plant that CFS will deploy by the mid-2030s.