The American plasma physicist who directed the Princeton Plasma Physics Laboratory and championed the development of a bold plan for U.S. fusion energy — bridging scientific research and energy policy.
ReviewedLast reviewed: 9 Aug 2026·Category: Scientists & Pioneers
Career
Stewart C. Prager served as director of the Princeton Plasma Physics Laboratory (PPPL) from 2009 to 2016 and is professor emeritus at Princeton University. He previously led the plasma physics program at the University of Wisconsin–Madison, where he directed the Madison Symmetric Torus (MST) reversed-field pinch experiment.[1]
PPPL Leadership
Diversification: During his tenure at PPPL, Prager expanded the laboratory’s mission beyond NSTX-U to include astrophysical plasma research, plasma nanotechnology, and partnerships with private fusion companies. He advocated for a fusion pilot plant as a near-term U.S. goal.
National Academy Study
Prager co-led the 2018 National Academy of Sciences study Final Report of the Committee on a Strategic Plan for U.S. Burning Plasma Research, which recommended that the U.S. pursue a compact pilot plant on an aggressive timeline. This study helped catalyse the 2022 White House fusion summit and the DOE’s Bold Decadal Vision for Commercial Fusion Energy.[2]
Research
Prager’s research contributions include magnetic self-organisation in reversed-field pinches, current profile control, and the physics of magnetic reconnection.[3]
Sources
National Academies of Sciences, Engineering, and Medicine. Final Report of the Committee on a Strategic Plan for U.S. Burning Plasma Research. The National Academies Press, 2019.