SPARC

Overview

Compact, high-field tokamak designed to demonstrate net energy from fusion. It uses high-temperature superconducting magnets to achieve reactor-class magnetic fields in a much smaller machine, with peer-reviewed projections of roughly Q ~11 and ~140 MW of fusion power.

Assembly is advancing at the Devens campus. As of April 2026, CFS says the facility is about 75% complete, with both halves of the vacuum vessel and two of the 18 toroidal field magnets in Tokamak Hall.

Key Specs