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. SPARC is about 75% complete: the first of 18 toroidal-field magnets was installed at CES 2026 in January, the second 48-ton vacuum-vessel half was lowered into Tokamak Hall in May 2026, and CFS targets having all 18 TF magnets installed by end of summer 2026 ahead of first plasma and a Q>1 net-energy attempt in 2027. CFS is also building an AI-powered digital twin of SPARC with Nvidia and Siemens.

Key Specs