MIT: On Track to Create a Fusion Power Plant

Dennis Whyte is the director of the Plasma Science and Fusion Centre (PSFC). He is reflecting upon a core belief that guided his 22.63 class in nuclear engineering (Principles of Fusion Engineering). His students have just presented their final presentations about using fusion technology to create carbon-free fuel to ship vessels. Whyte started the course more than a decade ago and has encouraged the class to collaborate on solving “real-world” problems. The system and its collaborative approach to design have been crucial in shaping the future of fusion at PSFC over the years.

Since the 1970s, fusion has been a topic of interest to researchers. The process powers the sun and provides almost unlimited, carbon-free energy. MIT has been studying the process using a series of “Alcator tokamaks,” compact machines that use high magnetic fields to keep hot plasma in the vessel and away from the walls. Fusion can only occur if the vacuum vessel is shaped like a donut. It is difficult to understand how plasma reacts with tokamak materials and makes it hot enough to sustain fusion reactions.

Design teams and incubating fusion machines

Whyte was available to help his students tackle problems in net-energy tokamak operations, which is necessary to generate substantial economic power. These issues could not be investigated with the PSFC’s Alcator C-Modtokamak, which kept fusion in very short pulses. However, they could be examined by a class tasked to design a fusion device capable of operating around the clock.

Whyte was also introduced to high-temperature superconducting (HTS) tape), a new class of superconducting materials that allowed for higher magnetic fields and effectively constrained the plasma. It could surpass the performance of previous generations of superconductors like niobium, which was used in ITER (the burning plasma fusion experiment in France). The class could design a machine to answer questions about stable-state operation while using this new product. What if the components could be removed and altered easily, making them flexible for different experiments?

The class created a tokamak named “Vulcan” and published five peer-reviewed articles in Fusion Engineering & Design. The tokamak design still needs to be built, but its exploration of magnetic coils made from HTS tape suggested a path toward a future of fusion.

This path was followed by Whyte’s students two years later. He wondered, “What would happen if we tried to make 500 megawatts of fusion power — the same as ITER –, but we use this HTS technology?”

Whyte wanted to encourage collaboration in the classroom by having student teams work on different aspects of the project and then coordinate with other groups to create a cohesive design. He invited PSFC Fusion experts to participate. The students could build upon the previous class’s research and form the basis for HTS magnets and demountable coils.

The paper published the results of the research. Brandon Sorbom, a graduate student then, was the lead author. Brandon Sorbom, Ph.D. ’17 was the first to introduce the fusion community. He described ARC as “a compact high-field, fusion nucleus science facility, and demonstration plant with demountable magnets.” Whyte and his students began to think about ways they could examine the most critical aspects of the ARC design in a smaller unit.

SPARC was the answer based on their experience with designing Vulcan, ARC. The compact, high-field net fusion energy experiment is now a collaboration between MIT (CFS) and Commonwealth Fusion Systems, a Cambridge, Massachusetts-based startup seeded with talent starting at 22.63. Dan Brunner and Bob Mumgaard, who were instrumental in designing Vulcan’s technology, are both CFS leaders, and Brandon Sorbom. Zach Hartwig, MIT NSE Assistant, was a student involved in Vulcan’s design. He has also remained involved in SPARC and its developments.

The economic question

It had been a hub for researchers who wanted to use the most recent technology to help reimagine the speed of a fusion power station. The course helped the PSFC shift its focus from Alcator C-Mod, which shut down in 2016, to SPARC and ARC. It also allowed for technological innovation. The PSFC realized that its fusion program was primarily funded by the U.S. Department of Energy and would need to increase its sponsorship for private funding.

The private sector was also involved in discussions that revealed the need for fusion to be economically viable. Whyte was inspired to add an economic constraint in the 2020 22.63 class project. He noted that it “changes how you approach the design.” Eric Ingersoll is the founder and managing director of TerraPraxis and LucidCatalyst. They came up with an innovative application for fusion that would allow international shipping to be a carbon-free, intense energy source.

This year’s virtual course allowed students, postdocs, and teachers from Princeton University to participate in the class as volunteers. The goal was to create a similarly structured course at Princeton eventually. They joined MIT students and teachers to form four teams that worked together interdependently on a method for generating ammonia fuel in ship engines. “ARCH” was the device’s name, with H standing for Hydrogen. The team demonstrated they could meet economic targets by innovating the fusion design. They mainly focused on heat removal and improving materials.

Rachel Bielajew was a graduate student at MIT and part of the Systems Integration Team. She found that focusing on economics provided a different experience than her classes.

She says, “It was certainly motivating to choose an economically driven design.” “The class reinforced that successful fusion reactors are multidisciplinary and that significant research must be done in many areas.

Whyte’s journey as a teacher has been just as transformative for himself as it was for his students.

He says, “If you give young people time, the tools, and the imagination to work together towards meaningful ends — it’s difficult to imagine a stronger force.” “The class and the innovative student efforts have transformed my worldview, and I believe that fusion energy is possible because of the class and their collective effort.”