SPARC is a tokamak under development by Commonwealth Fusion Systems (CFS) in collaboration with the Massachusetts Institute of Technology (MIT) Plasma Science and Fusion Center (PSFC).

[3] SPARC plans to verify the technology and physics required to build a power plant based on the ARC fusion power plant concept.

[2][1] The project is scheduled to start operations in 2026, with the goal of demonstrating net power (Q > 1) in 2027.

[9] In March 2021, CFS announced that it planned to build SPARC at its campus in Devens, Massachusetts.

[10] In September 2021, the project successfully tested a prototype toroidal high-field coil, achieving a record for high-temperature superconducting magnets, with a field strength of 20 T at the temperature of 20 K.[11] In November 2024, a prototype of the reactor's central solenoid was demonstrated, and the building housing SPARC in Devens was largely completed, with assembly of the SPARC tokomak in early stages.