PPPL: Distinguished Oxford physicist named head of world-class PPPL Theory Department

Plasma physicist Felix Parra Diaz, a distinguished scientist and Oxford University professor who has studied, taught and won high honors on both sides of the Atlantic, has been named head of the Theory Department(link is external) at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL). He succeeds Amitava Bhattacharjee, who stepped down at the end of May 2021 to resume full-time teaching and research after nine years of leading the department. Stuart Hudson is presently serving as interim Theory Department head.

“I’m very excited to come to the U.S. and PPPL looks like a very exciting place right now,” said Parra Diaz, whose new position begins Oct. 1, 2021. Included is a professorship at Princeton University, which manages the Laboratory. “This is a terrific opportunity to work with all the Theory Department people. I’m really looking forward to building this team together with everyone,” he said.

Plug scientific gaps

“Overall, what the Theory Department needs to do is to plug the scientific gaps that we need to fill to design fusion reactors(link is external),” he said. “It’s the biggest Theory Department in the U.S. and probably in the world so we’re really situated to develop the tools that are needed to design and move forward with fusion development.”

In his new role, Parra Diaz will oversee 48 regular staff members in the Theory Department, which also includes visitors, affiliates of Princeton University and others who bring the total number of theorists to close to 100. In addition, he will collaborate with the Lab’s new computational sciences group to incorporate exascale computing to help solve fusion challenges, and with the Lab’s efforts to understand the plasma universe from the nano to astrophysical scale.

Fusion, the power that drives the sun and stars, combines light elements in the form of plasma(link is external) — the hot, charged state of matter composed of free electrons and atomic nuclei, or ions, that makes up 99 percent of the visible universe — to generate massive amounts of energy. Scientists the world over are seeking to produce and control fusion on Earth for a virtually inexhaustible supply of safe and clean power to generate electricity for all humanity.

PPPL Director Steve Cowley, who stresses the need for innovation to fill current scientific and engineering gaps, looks forward to Parra Diaz’s arrival. The two scientists worked together when Cowley headed the Culham Centre for Fusion Energy(link is external), the United Kingdom’s national laboratory for fusion research, and Parra Diaz was at Oxford from 2013 until the present. “I am delighted that we managed to attract Felix to PPPL – he is an astonishingly creative theorist. Those of us who have worked with him are humbled by the speed and surety of his insights.”

Also anticipating Parra Diaz’s arrival is Jon Menard, PPPL deputy director for research who oversees the Theory Department. “I am very much looking forward to working closely with Felix on helping to move the Lab’s research initiatives forward – especially for leveraging PPPL’s unique strengths in plasma theory for advancing stellarator and spherical tokamak-based fusion pilot plants” Menard said.

Wide-ranging interests

Parra Diaz’s wide-ranging science interests include the use of plasma for fusion energy and space propulsion. He has authored or co-authored more than 100 high-profile papers and invited talks on plasma physics ranging from the behavior of plasma in doughnut-shaped tokamaks and twisty stellarator facilities to the operation of powerful accelerators that pulse high-speed particle beams.

Parra Diaz looks forward to learning about the Theory Department’s work. “The people in the Theory Department know what they’re doing and I will need to listen,” he said. “What are the concepts and tools that we don’t have and that PPPL theory can either provide or help other people or groups in the U.S. to achieve? We need to figure out what is missing and what we as a fusion community need to do. This is very important because the U.S. is getting closer to having to design fusion power plants.”

A native of Spain, Parra Diaz received his bachelor’s degree in aeronautical engineering with a specialization in propulsion from the Polytechnic University of Madrid. He ranked first out of 240 students and played on the university’s rugby team, a sport he also played in high school and in which he remains a fan.

He next crossed the Atlantic to the Massachusetts Institute of Technology (MIT), where he earned first a master’s degree and then a doctorate in 2009. His dissertation won the coveted Marshall N. Rosenbluth Outstanding Thesis Award and he played on the MIT Rugby Football Club in the New England Rugby Football Union.

Aerospace engineer

“I am by education an aerospace engineer,” he said. “Jet engines and rockets in fact. But at MIT many of the plasma subjects are taught by the fusion group. So I shifted from plasma thrusters to theory in fusion and I completely bought into the idea of fusion after I learned how it works. It’s such a beautiful idea and we’re getting so close.”

He next spent two years as a post-doctoral fellow at the University of Oxford before becoming an assistant professor at MIT from 2011 to 2013. His research in that position won him a highly competitive DOE Early Career Award. He returned to Oxford as an associate professor in 2013 before becoming a full professor in 2019. While at Oxford he won the Best Young Theoretical Physicist Award of the Spanish Royal Physical Society.

In recent years U.S. fusion has been turning around, he said. “PPPL is expanding, start-ups are opening up and I think the momentum is back in the U.S. fusion program. My decision now is to move fusion ahead.”

Parra Diaz and his wife, Violeta, a structural engineer, have three small children, sons Marcelo and Lope, ages 1 and 8, and daughter Eulalia, aged 5. When Parra Diaz is not working he enjoys teaching Rugby to his older son, Lope – and he hopes that his daughter Eulalia will get interested in the sport soon.

At PPPL Parra Diaz will be among some familiar faces from his student and teaching years. Among them is physicist Greg Hammett, who has collaborated with Parra Diaz on several projects; Arturo Dominguez, senior program leader in the Science Education Department who was an MIT graduate student along with Parra Diaz; physicist Michael Churchill, an MIT graduate student when Parra Diaz taught there; physicist George Wilkie, who collaborated with Parra Diaz while in Europe; and Princeton University professor Matt Kunz, whose post-doctoral work at Oxford overlapped with Parra Diaz’s. In addition, physicist Bill Dorland of the University of Maryland and associate director of computational science at PPPL co-supervised Parra Diaz’s thesis at MIT. “This is one of the great things about PPPL,” Parra Diaz said. “Virtually every U.S. plasma physicist is somehow connected to it!”