PPPL’s Jack Berkery receives Fulbright Specialist award to share research on spherical tokamaks

(Press-News.org) In a field where collaboration is key to progress, Jack Berkery, a leader in U.S. fusion research, is heading to Japan as a Fulbright Specialist to help strengthen the ties that power the future of fusion energy. Berkery is the deputy director of the National Spherical Torus Experiment-Upgrade (NSTX-U) at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL). The Fulbright Specialist Program pairs specialists with select host institutions to build international partnerships. 

Berkery’s two-week visit to Japan will include meetings with researchers at Kyushu University and participation in a plasma physics conference. During the first week, Berkery will visit the university to give lectures, meet with students and explore opportunities for joint research. “The intention is to give some talks at the university and sit down with students to go through their projects,” he said. “I’ll also be talking to professors about what we can do in collaboration.”

In the second week, Berkery will present PPPL research at the Asia-Pacific Conference on Plasma Physics, hosted by the Association of Asia Pacific Physical Societies’ Division of Plasma Physics. His presentation will focus on spherical tokamaks and preparations for NSTX-U’s next phase of operations. Berkery hopes the trip will strengthen ties between spherical tokamak researchers and inspire joint projects.  

Exploring the future of spherical tokamaks, together

Tokamaks such as NSTX-U use magnets to confine hot plasmas, allowing plasma atoms to fuse together and release large amounts of energy. NSTX-U is shaped more like a cored apple than the squatter, doughnut-like shape of conventional tokamaks. NSTX-U is designed to determine whether this spherical shape is the best design for a commercial fusion plant. 

Japan has several spherical tokamaks, including Kyushu University’s device, the Q-shu University Experiment with Steady-State Spherical Tokamak (QUEST). Berkery said insights from QUEST are relevant to his team’s work on NSTX-U. It also ties in with PPPL’s work with other existing spherical tokamak experiments around the world, including PPPL’s partnership with the University of Seville in Spain on the SMall Aspect Ratio Tokamak (SMART), as well as the design of future devices, such as work with private company Tokamak Energy in the United Kingdom and possibly Japan’s national Fusion by Advanced Superconducting Tokamak (FAST) program.

PPPL and Kyushu University have collaborated informally before, and Berkery hopes the visit will deepen ties. “There’s a lot of potential for growth,” he said. “We’ve had positive conversations, and this trip is a step toward building something more substantial.”

Berkery’s appointment as a Fulbright Specialist reflects growing interest in global cooperation to advance fusion energy, a field where countries like the U.S., U.K., Japan and Spain are key allies. “To remain competitive, we need to collaborate with our partners,” Berkery said. “Fusion research is a relatively small, highly specialized community, and working together benefits everyone.”

Fulbright Specialists can partner with multiple hosts during their tenures. Berkery hopes to be paired with the University of Seville next, so that he can continue his work with the SMART team now that the tokamak is operational.


PPPL is mastering the art of using plasma — the fourth state of matter — to solve some of the world’s toughest science and technology challenges. Nestled on Princeton University’s Forrestal Campus in Plainsboro, New Jersey, our research ignites innovation in a range of applications, including fusion energy, nanoscale fabrication, quantum materials and devices, and sustainability science. The University manages the Laboratory for the U.S. Department of Energy’s Office of Science, which is the nation’s single largest supporter of basic research in the physical sciences. Feel the heat at https://energy.gov/science and http://www.pppl.gov.  

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