The fusion energy research program at the Department of Energy's Oak Ridge National Laboratory is not confined to one division, or even one directorate, but rather cuts across almost the entire laboratory, from high performance computing to advanced manufacturing to novel materials for fusion reactors. This breadth of capabilities, coupled with the push to bring a fusion pilot power plant online in the 2030s, can be a daunting prospect to coordinate and manage.
Thankfully, Fusion Energy Division Director Troy Carter has had some practice tackling big challenges, with more than two decades of experience as a college professor and leadership roles in both national and international fusion research advisory committees.
"I have a Ph.D. in herding cats," he said. "Somehow I've got the personality and temperament that has been useful in motivating and working with people to get difficult things done."
Carter oversees the lab's wide-ranging research in plasma physics, fusion technologies, and fusion-facing materials, as well as major projects like the Material Plasma Exposure eXperiment , or MPEX, a next-generation linear plasma device currently under construction that will enable researchers to test new materials and components that can withstand the extreme heat and magnetic fields within a fusion reactor.
He is also responsible for raising ORNL's prominence in the fusion community and stewarding the public-private partnerships between ORNL and the fusion industry. Both the public research sector and private fusion industry recognize that collaboration is vital at every level, both domestically and internationally. To succeed, fusion facilities all over the world must cooperate to leverage their unique capabilities to answer key questions and prevent the duplication of effort, which would close some of the science and technology gaps and accelerate the development of commercial fusion power.
"Fusion is one of those challenges where you need to have all hands on deck," Carter said. "There are too many problems for one company or lab to solve, especially if we want to do this on a decadal timescale, so we really have to work together."
Sparking an interest
A native of North Carolina, Carter's passion for fusion was ignited by a project in his high school chemistry class. He was assigned to argue the pros in a debate on nuclear energy, and through his research, he learned about fusion. He carried this newfound interest into college, where he studied physics and nuclear engineering at North Carolina State University, which had a well-established and esteemed fusion program.
"I think at the time I was obviously going to do something math and science-y, but the idea of working towards something that could have such an impact on society was the driver there, and it seemed cool," Carter said.
After NC State, Carter went to Princeton for graduate school, intent on working directly on fusion projects like the Tokamak Fusion Test Reactor, which had just become the first fusion device to achieve a 10-megawatt power output. Instead, he was drawn to a basic plasma physics program focused on understanding how solar flares release energy. This still kept him close to fusion, though, as the same principles he was studying in solar flares were also the main drivers of plasma instability in fusion tokamaks.
Carter then applied for a faculty position at the University of California, Los Angeles, where he joined their new Basic Plasma Science Facility, a national collaborative research facility for plasma science, to work on fundamental plasma physics projects with fusion applications and grow the facility's external user base. At the same time, he worked on projects at UCLA's Enormous Toroidal Plasma Device, then known as the Electric Tokamak, and the DIII-D National Fusion Facility, a DOE Office of Science user facility.
"I was on a trajectory where I had feet in both worlds, doing fundamental plasma physics that had relevance to space and astrophysical settings, as well as working on confinement physics using the machines at UCLA and DIII-D," he said.
Carter would eventually become director of the Basic Plasma Science Facility, as well as director of the Plasma Science and Technology Institute, an organized research unit at UCLA. His involvement in strategic planning at the university led to further committee work in the national and international fusion research communities, culminating in him leading the Fusion Energy Sciences Advisory Committee, or FESAC, Long Range Planning process that produced the 2021 report, " Powering the Future: Fusion & Plasmas ." For his contributions to plasma physics and fusion energy, and his leadership in these national strategic planning activities, Carter was recently elected as a fellow of the American Association for the Advancement of Science , or AAAS, one of the world's largest general scientific societies and publisher of the Science family of journals.
Closer to home
After 22 years at UCLA, Carter returned to the Southeast in July 2024 to begin his position as director of ORNL's Fusion Energy Division.
Coming back after so long on the West Coast has been a big transition, he said, but one that comes at the right time. It's a familiar place for him and closer to family, and since arriving, he has enjoyed getting outside, riding his bike on the trails of East Tennessee, finding new food spots, supporting the local symphony and cheering on Knoxville's sports teams.
While he loved teaching and being a professor, coming to ORNL was an opportunity to make a larger impact on the fusion program at one of the storied fusion labs in the United States. The lab has all the different pieces of an integrated fusion system, including plasma physics, fusion technology, and materials, with the expertise to match.
"Oak Ridge has all the capabilities that need to be brought to bear to help create a fusion industry in the United States," he said. "I think ORNL should be driving the conversation around public sector leadership toward this goal."
The fusion landscape has undergone many changes throughout his career, ebbing and flowing over time as projects and devices have come and gone. Recently, though, the excitement has regained momentum as investments rise for private fusion start-ups and a new generation enters the fusion research community, Carter said, making now an exciting time to be at a place like ORNL.
"There has been steady progress in the science throughout my career, but I think the most rapid changes in the field have been in the last five years. It's a convergence of many things at once, but certainly the private sector growth has been big," he said.
Carter envisions ORNL as the hub of fusion innovation, connecting people and institutions and balancing the needs of today with the ambitions of tomorrow. The goal is to commercialize fusion and enable the private sector to succeed, he said, but at the same time, national labs must take the long view and work on the fundamental research and development needed to ensure the long-term success of fusion.
"Those two things, they are synergistic and feed off of each other," Carter said. "Some of the fundamental R&D that you do may not be directly applicable to near-term industry needs but instead anticipates future needs. That's how the staff here become experts, push those boundaries and innovate. To get to that goal of economic fusion, we must keep pushing the frontier."
Mentorship for tomorrow
Mentorship has been an essential part of Carter's career, both as a mentor and mentee. Being a mentor is about more than just shepherding a student through the few years they are in school, Carter said, but about enabling them to succeed and, in turn, become a good mentor for the next generation.
"If you ask me my proudest achievement, it's not the papers, it's not the science. It's the students that came out of my time as a professor," he said. "While I hope I can do some more research going forward, my real role here is to help people be successful in whatever way I can but also enable the senior and mid-career staff to help the junior staff get the mentorship they need."
Much of the discussion around fusion focuses on the future and anticipating the needs of the field 10 to 20 years from now. Future fusion pilot plants will be designed and staffed by people currently in high school and college, so it is vital to raise the profile of fusion energy today and build the pipeline that will development the fusion workforce of tomorrow. Universities and community colleges are going to play a huge role in developing the necessary infrastructure, but national labs also have a role to play, Carter said.
"We will need Ph.D. scientists, yes, but we're also going to need people in technical roles, people who can weld, people who have worked in the nuclear field, people who can help plan big projects, who can run these companies, who can work with regulators and advocate and communicate," he said. "We need everybody to pitch in to grow the fusion industry that we need."
For anyone thinking about joining the field of fusion research, Carter offers a two-pronged approach: Find a part of fusion that excites you and have fun doing it.
"Fusion is so interdisciplinary, there are all kinds of ways you can contribute, so if you are interested in it, hopefully you can find a way that excites you and matches your skill set," he said. "Fusion has always been my passion. You want to find that element that you're passionate about and can have fun doing."
UT-Battelle manages ORNL for DOE's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. DOE's Office of Science is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science . - Sean Simoneau
