Timothy Stoltzfus-Dueck, a theoretical physicist at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), has won a DOE Early Career Research Award for exceptional scientists in the early stages of their careers. Stoltzfus-Dueck will use the five-year, approximately $500,000 per year award to develop and test models essential to the confinement of plasma, the hot, charged gas that must be tightly confined in doughnut-shaped devices to produce fusion reactions. Scientists around the world are seeking to replicate and control on Earth the fusion that powers the sun and stars to produce safe, clean and virtually inexhaustible energy for generating electricity.

Stoltzfus-Dueck, who joined PPPL in 2014, is focusing on the behavior of the edge radial electric field at the volatile edge of the plasma -- a region that strongly determines the confinement and overall performance of the plasma in magnetic tokamaks, or fusion devices. Such fields, which arise from the interaction of conditions that include turbulence and the collision of plasma particles, can suppress damaging disruptions and are thought to also suppress the turbulence that causes particles to leak from the magnetically confined region.

Plans simple model

Stoltzfus-Dueck plans to produce a simple model of the formation of the critical edge radial electric field. He will first test the model against prior large-scale simulations and then against data from actual experiments to develop insights that can enhance the prediction and control of the radial field for maintaining good confinement. "Basic physics understanding like this is important for predictions for ITER," he said, referring to the international experiment under construction in France to demonstrate the practicality of fusion energy. "Improved understanding could help us spot changes that will occur in such a large device."

The findings aim to increase understanding of the control of next-generation fusion plasmas. "Tim's work is characterized by deep physical intuition and rigorous mathematical analysis, and his work on plasma rotation has produced testable predictions by experiments and numerical simulations," said Amitava Bhattacharjee, head of the Theory Department at PPPL. "He has an unusual ability to connect with and impact experimental work. We eagerly look forward to his research on edge turbulence, which is a very important problem, and will be supported by the Early Career Award."

Jogs to work daily

Stoltzfus-Dueck, who jogs to work daily from his home some five miles from PPPL, has had a varied early career. He earned his doctorate from the Program in Plasma Physics at Princeton University in 2009 after receiving a bachelor's degree in physics and music in 1999 from Goshen College in Goshen, Indiana, where he studied piano and sang in the school choir. He then worked for two years as a community mediation director in the AmeriCorps Volunteer program before enrolling in plasma physics at Princeton. "I have always been interested in conflict resolution and peacemaking," he said, "but my skills are probably better suited to technical work."

After earning his doctorate, Stoltzfus-Dueck worked for five years at the Max Planck Institute for Plasma Physics in Germany, where he developed and experimentally verified a model of edge intrinsic plasma rotation. He then returned to PPPL where his research has included investigation of core intrinsic rotation and turbulence suppression in the edge. "Max Planck and PPPL are both fantastic places to work," he said. "PPPL is in the middle of the U.S. fusion program and has been a really great place for collaboration with so many top-notch scientists."

Stoltzfus-Dueck is the ninth PPPL physicist to receive a DOE Early Career Research Award since the current program was launched in 2010. He is among 73 scientists, including 27 from DOE national laboratories and 46 from U.S. universities, to be selected for the honor in 2019. In commenting on the awards, Secretary of Energy Rick Perry said, "Supporting our nation's most talented and creative researchers in their early career years is crucial to building America's scientific workforce and sustaining America's culture of innovation."

###

PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas -- ultra-hot, charged gases -- and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy's Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science (link is external).