Lauren Garrison

We have seen many advancements in the fusion field in the past handful of years. In 2021, the National Academies released a report titled Bringing Fusion to the U.S. Grid.^a In March 2022, the White House held a first-ever fusion forum, “Developing a Bold Decadal Vision for Commercial Fusion Energy.”^b The National Ignition Facility had a record-setting fusion pulse that achieved more power output than the laser input, called ignition, in December 2022.^c The Department of Energy’s Office of Fusion Energy Sciences (FES) started a new public-private partnership program, the fusion milestone program, in May 2023 that made awards to eight fusion companies in a cost-share model.^d That same summer, FES got a new associate director, Dr. Jean Paul Allain,^e who has announced intentions for changing the structure of the FES office to better embrace an energy mission for fusion while keeping the strong foundation in basic science and non-fusion plasmas. ITER construction has continued, with various parts being delivered and systems finished. For example, the civil engineering of the tokamak building was completed in September 2023 after 10 years of work.^f Even more fusion companies have been founded, and the Fusion Industry Association has 37 members now.^g

Commonwealth Fusion Systems (CFS) hosted visiting officials for a tour and ribbon-cutting ceremony to officially open its new headquarters in Devens, Mass., on February 10. Energy secretary Jennifer Granholm, Sen. Elizabeth Warren (D., Mass.), and Sen. Edward Markey (D., Mass.) were among the national, state, and local leaders invited to celebrate what CFS heralded as a “fusion energy campus.”

The Massachusetts Institute of Technology’s Plasma Science and Fusion Center (PSFC) recently announced it will expand its involvement in fusion energy research and education under a new five-year agreement with Commonwealth Fusion Systems (CFS), a fusion energy company that got its start at MIT and is now building what it says will be the world’s first net-energy fusion machine—the demo-scale SPARC.

“CFS will build SPARC and develop a commercial fusion product, while MIT PSFC will focus on its core mission of cutting-edge research and education,” said PSFC director Dennis Whyte in describing the collaboration.

Cutaway of the SPARC engineering design. Image: CFS/MIT-PSFC, CAD rendering by T. Henderson

Seven open-access, peer-reviewed papers on the design of SPARC, Commonwealth Fusion Systems’ (CFS) fusion tokamak, written in collaboration with the Massachusetts Institute of Technology’s Plasma Science and Fusion Center, were published on September 29 in a special edition of the Journal of Plasma Physics.

The papers describe a compact fusion device that will achieve net energy where the plasma generates more fusion power than used to start and sustain the process, which is the requirement for a fusion power plant, according to CFS.

The timeline for this planned device sets it apart from other magnetic confinement fusion tokamaks: Construction is to begin in 2021, with the device coming on line in 2025.

CFS expects the device to achieve a burning plasma—a self-sustaining fusion reaction—and become the world’s first net energy (Q>1) fusion system. The newly released papers reflect more than two years of work by CFS and the Plasma Science and Fusion Center to refine their design. According to CFS, the papers apply the same physics rules and simulations used to design ITER, now under construction in France, and predict, based on results from existing experiments, that SPARC will achieve its goal of Q>2. In fact, the papers describe how, under certain parameters, SPARC could achieve a Q ratio of 10 or more.

Cutaway of the SPARC engineering design. Image: CFS/MIT-PSFC, CAD Rendering by T. Henderson

A special issue of the Journal of Plasma Physics gives a glimpse into the physics basis for SPARC, the DT-burning tokamak being designed by a team from the Massachusetts Institute of Technology and Commonwealth Fusion Systems. The special issue was announced in a September 29 post on the Cambridge University Press blog Cambridge Core.

The special JPP issue includes seven peer-reviewed articles on the SPARC concept, which takes advantage of recent breakthroughs in high-temperature superconductor technology to burn plasma in a compact tokamak design.