Visualization of the proposed SPARC tokamak experiment. Using high-field magnets built with newly available high-temperature superconductor, this experiment would be the first controlled fusion plasma to produce net energy output. Visualization by Ken Filar, PSFC Research Affiliate


The MIT Plasma Science & Fusion Center has begun developing a conceptual design for SPARC, a compact, high-field, net fusion energy experiment. SPARC would be the size of existing mid-sized fusion devices, but with a much stronger magnetic field. Based on established physics, the device is predicted to produce 50-100 MW of fusion power, achieving fusion gain, Q, greater than 3. Such an experiment would be the first demonstration of net energy gain and would validate the promise of high-field devices built with new superconducting technology. SPARC fits into an overall strategy of speeding up fusion development by using new high-field, high-temperature superconducting (HTS) magnets.

The first step in this roadmap will be to carry out research leading to development of the large, superconducting magnets needed for fusion applications. To carry out this research, MIT is collaborating with a private fusion start-up company, called Commonwealth Fusion Systems (CFS). CFS will join MIT’s Energy Initiative (MITei) as part of a new University-Industry collaboration to execute this plan.

Once the basic engineering of HTS fusion magnets is established, the next step will be to use that technology to build SPARC. Preliminary analysis has led to a conceptual design with a 1.65m major radius and 0.5m minor radius operating at a toroidal field of 12 T and plasma current of 7.5 MA, producing 50-100 MW of fusion power. Its mission will be to demonstrate break-even fusion production and to demonstrate the integrated engineering of fusion-relevant HTS magnets at scale. While audacious in its goals, SPARC leverages decades of international experience with tokamak physics and is a logical follow-on to the series of high-field fusion experiments built and operated at MIT. The long term goal is to introduce fusion power into the energy market in time to help combat global warming.

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SPARC Founding Team

Martin Greenwald
Zachary Hartwig
Dennis Whyte

Collaborating Research Team

James Irby
Earl Marmar
Joseph Minervini
Anne White


MIT and newly formed company launch new approach to fusion power (MIT News)
3 Questions: Zach Hartwig on MIT’s big push on fusion (MIT News)

CFS (Commonwealth Fusion Systems)

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