Prager to lead DOE’s Princeton Plasma Physics Laboratory

Stewart Prager, director of the Madison Symmetric Torus experiment at the University of Wisconsin and an internationally recognized leader in the field of fusion energy research, has been named director of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), effective this fall.

Prager, who also is the Dexter Professor of Physics at Wisconsin, will become the sixth director of the laboratory, which is funded by the DOE and managed by the University. His appointment as a professor of astrophysical sciences at Princeton is expected to be acted on in the fall.

“We believe that there is no better person than Stewart Prager to lead the Plasma Physics Laboratory as it moves into the next phase in its distinguished history,” said Princeton President Shirley M. Tilghman. “The need for safe, abundant and environmentally benign sources of energy has never been greater, and we are confident that under his leadership PPPL will continue to make exceptional contributions to the field of fusion energy.”

Provost Christopher Eisgruber added, “Stewart Prager is not only a superb scientist, but also a proven leader of the nation’s fusion research community. All of us at Princeton are absolutely delighted that Dr. Prager has agreed to take the helm at the laboratory.”

Prager joined the Wisconsin faculty in 1977 after conducting research for two years with the Fusion Energy Group at the General Atomic Co. (now known as General Atomics) in San Diego. He is a pioneer in the field of plasma physics and is internationally known for experiments that have contributed to both fundamental knowledge and the design of future reactors.

Prager has made his name as an experimentalist in the quest to develop fusion energy, the energy that is released when atomic particles fuse together to form heavier particles. Fusion fuels the sun and other stars. Prager has played a key role for decades in efforts to harness the energy potential of nuclear fusion by working with charged gases known as plasmas.

On the Wisconsin “Levitated Octupole” experiment, Prager worked with a graduate student, Michael Zarnstorff, now a principal research physicist at PPPL, detecting for the first time the so-called bootstrap current, named because the electrical current is generated by the plasma itself. Prager and Zarnstorff will receive the American Physical Society’s Dawson Prize for Excellence in Plasma Physics this November.

Prager has led research on another experimental device, the DOE-funded Madison Symmetric Torus, directing a group that was the first in the world to completely characterize the chaotic flow of the charged gases swirling within. Shaped like a donut, the MST holds plasma heated to 10 million degrees. But instead of using a strong magnetic field to hold the plasma, Prager and his team have explored whether weaker -- and therefore more economical -- magnetic fields could accomplish the same task. The work has led to new insights about the properties of plasma.

Experiments that help identify and understand such phenomena are critical to the eventual goal of producing commercially viable fusion power plants.

Prager also has led the Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas. Funded by the National Science Foundation, the “physics frontier center” involves Wisconsin, Princeton and five other institutions.