PPPL researcher Lan Gao wins a DOE $2.75 million early career award to develop innovative diagnostic tools for future fusion energy devices

Princeton Plasma Physics Laboratory (PPPL) research physicist Lan Gao has received a 2024 Early Career Research Program (ECRP) award from the U.S. Department of Energy (DOE) to develop the next generation of diagnostic tools that will provide precise measurements for fusion experiments and future fusion pilot plants. 

Gao, a scientist at PPPL since 2016 and head of the High Energy Density Laboratory Plasmas Division of the Discovery Plasma Science Department, will receive $2.75 million over five years. She was one of 91 scientists to whom the DOE awarded a total of $138 million for their research. She is the eleventh PPPL scientist to win an Early Career Award at PPPL since 2010. 

“It’s really a great honor to receive this award,” Gao said. “The diagnostics we’re going to be developing using this award will be essential tools to understanding the behavior of plasmas in fusion energy experiments and will help solve challenging problems as we develop commercial fusion. I am looking forward to working with scientists at other institutions, national labs and private companies on these tools.” 

“We are so proud of Lan for receiving this well-deserved award, which will enable her to lead efforts to develop advanced X-ray diagnostic tools for both magnetic and inertial fusion science and energy research and development,” said Jonathan Menard, deputy director for research and chief research officer, who was an Early Career Award winner himself (then the Presidential Early Career Award) in 2004. “Her work will continue the outstanding and groundbreaking research in plasma diagnostics that has taken place at PPPL for decades.” 

Gao said she is excited to contribute to plasma physics and fusion energy science at a crucial time in the field. “We are entering a very exciting era for fusion,” she said. “There is a huge need for fusion to address climate change and the energy crisis.” 

Appointed head of High Energy Density Laboratory Plasmas Division

This has been a big year for Gao. In July, she was appointed head of the High Energy Density Laboratory Plasmas Division in PPPL’s Discovery Plasma Science Department. She leads a team of scientists who are researching diagnostic tools that can explore physics problems in high energy density (HED) and fusion energy experiments. “Our Lab is becoming a multipurpose laboratory, and I see a lot of support for high energy density physics,” Gao said. “I’m very inspired by the momentum we have now, and I’m constantly thinking about how I can contribute.” 

Gao and her team plan to develop advanced X-ray spectroscopic tools to detect and measure particles of light called photons. These tools could be used in different kinds of fusion experiments. This includes magnetic confinement facilities like PPPL’s National Spherical Torus Experiment-Upgrade and ITER, the international fusion experiment in France, as well as inertial confinement fusion experiments in which a burst of energy is created by pointing very powerful lasers at a highly condensed fuel pellet, such as the fusion experiments at the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) & Photon Science. 

Plans for innovative diagnostics 

Gao plans to develop a suite of innovative X-ray diagnostics that are “rad hardened,” meaning they can withstand the harsh environment of fusion experiments in which they are exposed to super high levels of radiation and heat. This includes X-ray spectrometers that use nonspherical crystals to create a more flexible configuration that would result in clearer images and X-ray imaging systems for an X-ray spectrometer that uses two spherical-shaped crystals to provide very high resolution images. 

The diagnostics will be used to explore fundamental physics questions in inertial confinement fusion. They could be used, for example, to understand and quantify how the impurities from the fuel used in the experiment enter the plasma. That could lead to development of better materials for inertial fusion.

Gao led the effort to develop and fully calibrate multiple spectrometers at NIF. The laboratory made headlines when scientists achieved a net gain of energy in December 2022. She is also the lead physicist for a diagnostic PPPL is developing for ITER and contributes to another diagnostic at the Japan-Torus-60 Super Advanced fusion device. 

Gao said she is grateful to have worked with and been mentored by physicist Hantao Ji, a professor of astrophysical sciences at Princeton University and a distinguished research fellow at PPPL, and by emeriti physicists Manfred Bitter and Ken Hill, both of whom are retired, whose X-ray diagnostics are used on fusion facilities all over the world. Gao was one of the inventors, with Bitter, Hill, Philip Efthimion, Luis Delgado-Aparicio and Novimir Pablant, of a patented Multi-cone X-ray imaging Bragg crystal spectrometer, and she has filed invention disclosures for several other ideas. “I really appreciate the training I got with the X-ray team here,” Gao said. “I’m very fortunate to work with the X-ray giants like Manfred and Ken over the years. I am honored for my team to carry the torch.” 

Began studying plasma physics in college 

Gao grew up in Xi’An, a large city in western China. She was always a good student in mathematics and science and was in a gifted class for high school students. She wasn’t sure what she wanted to study in college but began studying plasma physics at the University of Science and Technology in Hefei, China, where she graduated with a bachelor’s degree in physics.

She came to the U.S. for graduate school at the University of Rochester, where she received a doctoral degree in mechanical engineering. She studied lasers and high energy density plasmas as part of a Horton Fellowship at the University of Rochester’s Laboratory for Laser Energetics, where she worked for six years. Her thesis research on magnetohydrodynamic effects in laser-driven HED plasmas was published with Gao as the first author in the prestigious Physical Review Letters . 

Gao went on to study magnetic reconnection as a postdoctoral research associate at Princeton University’s Department of Astrophysical Sciences for two years before joining PPPL in 2016.  

A mentor to undergraduates 

Gao said she enjoys working with students and early-career scientists and has been a Science Undergraduate Laboratory Internship mentor to a student each summer for the past several years and an adviser to graduate students in the Princeton Program in Plasma Physics. 

In graduate school, Gao met her husband Lan Qing, a former physicist who is currently an entrepreneur. The couple has a 6-year-old son, Song, and they live in West Windsor, New Jersey. Gao said she appreciates her husband’s “unconditional support” for her career. 

Gao said creating a diverse and inclusive workplace at PPPL is very important to her. She is a member of PPPL’s Asian Cultural Alliance Employee Resource Group and has shared her own culture with her colleagues by organizing Chinese New Year’s celebrations with a feast of dumplings. She volunteers at PPPL’s Young Women’s Conference and the DOE’s New Jersey Regional Science Bowl, which PPPL hosts. 

One thing she appreciates most at work, she said, is having a group of people who offer support and work well together. “The thing I really like about PPPL is definitely the people,” Gao said. “I have a fabulous team, and I’m really grateful for them.”