Newswise — An early career physicist with a strong background in plasma physics who is focused on laser-based diagnostics has been appointed to a fellowship that honors pioneering physicist Robert A. Ellis Jr. and is aimed at encouraging more diversity in plasma physics research at the Princeton Plasma Physics Laboratory (PPPL).

Marien Simeni Simeni, currently at the University of Minnesota, is the first recipient of  the two-year Dr. Robert A. Ellis Jr. Postdoctoral Fellowship, with the option to extend to three years. Simeni Simeni will work on research projects with a senior PPPL researcher and will do outreach to undergraduate students of color to encourage careers in plasma physics. Lab leaders plan to name at least one new Robert Ellis postdoctoral fellow each year. 

Steve Cowley, PPPL director, first proposed establishing a fellowship in Ellis Jr.’s honor. Cowley knew Ellis when Cowley was a graduate student at PPPL. “I’m very pleased that PPPL can pay tribute to Robert Ellis Jr. by naming a fellowship aimed at diversifying the physics field in his honor,” Cowley said. “I’m also delighted that we are able to offer the fellowship to an accomplished early-career physicist like Marien.”

Named for a pioneer in plasma physics

Robert Ellis Jr. was a pioneer in modern experimental plasma physics who joined the Laboratory when it was still called Project Matterhorn in 1956 and was headed by lab founder Lyman Spitzer Jr.

One of the very few African American physicists at the time, he remained a leader in plasma physics until his death in 1989. Ellis was a key member of the team studying the magnetic confinement of plasma in stellarators. He became head of experimental projects at PPPL in 1988, heading all non-Tokamak Fusion Test Reactor experiments. 

Ellis devoted much of his time later in his career to furthering international collaboration in science. He served as foreign secretary of the Advisory Committee on the USSR and Eastern Europe of the National Academy of Science. He was also a member of the Science Advisory Committee for the NASA Research Laboratories and was head of the physics section of the International Atomic Energy Agency in Vienna. Ellis Jr.’s son, also named Robert (Bob) Ellis, is the chief engineer at PPPL.

Leadership development component

Jon Menard, deputy director for research, will be Simeni Simeni’s senior mentor and will provide additional research and career guidance. Menard said the leadership development component of the fellowship and the freedom to choose among research topics make the fellowship unique. “We want the fellows to be successful in whatever field they pick,” he said.

Menard was one of the organizers of the program, along with Andrea Moten, associate Human Resources director; and Diana Martin, executive assistant to Menard and Michael Zarnstorff, chief scientist. Menard said Simeni Simeni is an accomplished physicist who will be a strong addition to PPPL’s research in diagnostics that measure and analyze the plasma during fusion experiments. “I’m excited about the science and I’m excited about helping to get a more diverse team at PPPL,” Menard said. “Marien is an excellent physicist and very bright and energetic. He’s really going to do a lot to contribute to the diagnostic area.”

Inspiration for recipient

Simeni Simeni, who is currently living in Minneapolis, said he has long been interested in fusion energy and was delighted to be the first to be named to the Ellis Fellowship. “I am very, very much honored,” he said. “It’s very inspiring. It pushes you to do better and to do as well as Dr. Robert Ellis.”

Simeni Simeni said he has wanted to work at PPPL for many years. “If you want to become a better researcher and scientist you need to work with great researchers and scientists,” he said. “Because I always wanted to excel in plasma physics I always wanted to come to PPPL as a career path and when I got the opportunity to apply there, I didn’t hesitate!”

The physicist grew up in Cameroon, Central Africa. The seventh of eight children of a mother who was a high school physical education teacher and a father who was a high school biology teacher, his father encouraged his love of science from an early age. Simeni Simeni said his parents taught him the value of education and he enjoyed teaching high school students as a requirement of his graduate school. He is looking forward to the outreach aspect of the fellowship in which he will give presentations at historically black colleges and universities and other institutions. “To me, it’s very important to link research and teaching because it’s giving back and mentoring and inspiring the young to come and carry out the research,” Simeni Simeni said.

By the time he reached high school, Simeni Simeni was reading books by French mathematician and physicist Blaise Pascal but had never seen a science laboratory. A gifted mathematician, Simeni Simeni was planning to study mathematics when he began college at the University of Technology of Troyes. But he became interested in physics in a college course and his professor and mentor, Timothée Toury, encouraged him to transfer to the prestigious École Normale Supérieure, of Cachan (now École Normale Supérieure Paris-Saclay) where he received a bachelor’s degree in physics. “I had all the access to the broad spectrum of physics,” Simeni Simeni said. “It was very challenging but so delightful!”

Simeni Simeni went on to earn a Master of Science degree in aerospace engineering at the École Centrale in Paris. He spent the last six months of the program at the Office National d’Etudes et de Recherches Aérospatiales (ONERA), the French national aerospace research center where he worked on simulations of aircraft indirect combustion noise. He went on to obtain a Ph.D. from the university. For his Ph.D. thesis, he developed a laser diagnostic that measures nitrous oxide in a nanosecond discharge.

After receiving his doctorate in 2015, Simeni Simeni worked as a postdoctoral researcher at the Ohio State University. He has been a research associate at the University of Minnesota since 2018, during which time he was a visiting researcher at Sandia National Laboratory, another of the DOE’s national labs 

A choice of research projects

Working with PPPL physicist Ahmed Diallo, Simeni Simeni will choose a research area related to his expertise in both plasma physics and laser-aided plasma diagnostics. “This fellowship gives him some freedom to choose what he wants to do,” Diallo said.

One project Diallo is leading, funded by PPPL Laboratory Directed Research and Development funds, involves using extreme ultraviolet (EUV) lithography to study the physics of laser and tin droplets. The research could have applications in microelectronics and semiconductor manufacturing, which has been identified as a new collaborative research area for PPPL.

Another possible project involves developing a laser-aided diagnostic that could be used to measure the density of neutral deuterium in fusion experiments.

Diallo said he too has admired the career of Robert Ellis Jr. since he first learned about him as a young physicist and he likes being part of the first Ellis Fellowship program. “I’m quite happy. It’s an honor,” he said. “It’s really good to see Ellis recognized in the Lab. It’s a big step forward.”

Moten, who has worked on diversity and inclusion at PPPL for decades, echoed that sentiment. “"I’m absolutely thrilled that I was able to be a part of crafting this fellowship and seeing it to completion,” said Moten. “It’s  difficult to find underrepresented minorities in plasma physics and  recruiting Marien  will only add to the richness of the laboratory and its potential research capabilities.”

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 largest single 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, please visit