Commonwealth Fusion Systems installs reactor magnet, lands deal with Nvidia
The fusion power frontrunner said that construction on its Sparc reactor was proceeding as planned. Meanwhile, it's building a digital twin to help dial it in.

TL;DR
- CFS installed the first magnet in its Sparc fusion reactor at CES 2026.
- The Sparc reactor will have 18 magnets to create a magnetic field for plasma confinement.
- The goal is for the plasma to release more energy than is used to heat and compress it.
- CFS is working with Nvidia and Siemens to develop a digital twin of the reactor for faster learning and experimentation.
- The company has raised nearly $3 billion to date.
- CFS estimates its first commercial-scale power plant, Arc, will cost several billion dollars more.