Commonwealth Fusion Systems said Tuesday at CES 2026 that it has installed the first superconducting magnet for its Sparc fusion reactor, a key milestone for the experimental system the company aims to activate next year, TechCrunch reported.
The magnet is the first of 18 planned for Sparc, which is designed to confine superheated plasma inside a torus-shaped magnetic field strong enough to enable fusion reactions that generate more energy than they consume. CFS said it expects to complete installation of all magnets by the end of the summer.
Each magnet weighs about 24 tons and can generate a magnetic field of roughly 20 tesla, far stronger than medical imaging systems, once cooled to near absolute zero. The magnets will be mounted on a large stainless-steel cryostat installed last year, while plasma inside the reactor is expected to reach temperatures exceeding 100 million degrees Celsius.
As it prepares for operations, CFS said it is developing a full digital twin of the Sparc reactor in partnership with NVIDIA (NVDA) and Siemens (SIEGY) (SMAWF). The model is intended to integrate design, manufacturing, and operational data, allowing engineers to test adjustments virtually and compare simulations with real-world performance as the reactor is assembled and operated.
CFS has already relied heavily on simulation tools, but the company said the digital twin will allow continuous side-by-side analysis with the physical machine, potentially accelerating learning and reducing risk.
The company has raised nearly $3 billion to date to fund Sparc and future development. CFS plans to follow Sparc with Arc, its first commercial-scale fusion power plant, which it expects will require several billion dollars more in investment.