With nearly 200 attendees, the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) brought energy to the 66th Annual Meeting of the American Physical Society Division of Plasma Physics (APS-DPP) in Atlanta Oct. 6-11.

Scientists, graduate students, summer interns and staff from PPPL met with others from the plasma physics community to discuss the latest research and ways to advance the field. 

“Everybody brings their work, and everyone discusses everyone else’s. It's like drinking from a firehose,” said Lab Director Steve Cowley. “It’s amazing.” 

An abundance of research about astrophysical plasmas, sustainability sciences and low-temperature plasmas was discussed. But, as usual, fusion was the hot topic. There were many opportunities to discuss collaborations between national labs, universities and private companies, including Commonwealth Fusion Systems, Thea Energy, Tokamak Energy and Type One Energy.
 

A Maxwell Prize acceptance and memorial

As the winner of the 2024 James Clerk Maxwell Prize, Greg Hammett gave an invited talk at the conference, summing up 35 years of work with co-winner Bill Dorland on computer simulations of five-dimensional plasma turbulence in tokamak fusion systems to try to improve fusion power plant performance. His talk was followed by a memorial to Dorland, who passed away in late September after battling chordoma, a rare form of cancer, for decades.

Staff Research Physicist Noah Mandell, who worked with both Maxwell winners, gave a moving speech summarizing their impact on his career and the field at large. “[Bill] was a giant, a hero to me and so many others,” said Mandell, a 2021 Princeton graduate. “From Bill, I learned the power of big ideas, which, especially for young students, can be the inspirational spark needed to give them the freedom to explore, take initiative and develop their own passions and big ideas. From Greg, I learned the importance of the little steps: the details needed to realize those big ideas.”
 

PPPL research front and center

Jonathan Menard, deputy director for research and chief research officer, said the Lab’s impact at the conference was clear. “PPPL’s work was front and center at APS-DPP during the poster sessions, invited talks and contributed oral presentations,” Menard said. “It is clear that our research is highly influential in the field.”

Other PPPL invited talks included:

• Principal Research Physicist Igor Kaganovich – “Advanced Plasma Modeling Tools That Can Simulate Plasmas Used for Semiconductor Processing”
   
• Staff Research Scientist SangKyeun Kim – “Achieving ELM-suppressed Operation With the Highest Performance in DIII-D and KSTAR via Adaptive and Machine Learning Controls”
   
• Postdoctoral Researcher Boting Li – “Sawtooth Suppression by Flux Pumping on HBT-EP”
   
• Associate Research Physicist Ivan Romadanov – “Enhancing Plasma Diagnostics With Structured Light and Wavelength Modulation Spectroscopy”
   
• Associate Research Physicist Álvaro Sánchez Villar – “On the Development of Robust Real-time Capable ICRF Modeling via Machine Learning”
   
• Research Physicist and Deputy Head of Discovery Plasma Science Jongsoo Yoo – “First Laboratory Detection of Anomalous Resistivity and Electron Heating by Lower Hybrid Drift Waves Inside Reconnecting Current Sheets With a Guide Field”
   

Autria Aidun, who participated in PPPL’s Science Undergraduate Laboratory Internships program, won an APS-DPP award for her poster on liquid lithium flow tracking in the LTX-β tokamak. “This was my first time presenting at a conference,” said Aidun. “It has been really exciting to meet some of the leading researchers in the field.”
 

The continued relevance of ballooning instabilities

Cowley provided an insightful overview of the work of Bob Dewar, a former PPPL staff scientist, and his colleagues for their contributions to ballooning modes, which are instabilities that can cause plasma in a fusion system to jut out from the core like a long balloon. Dewar, who worked at PPPL in the 1970s and 1980s, passed away in April 2024. Cowley brought the work up to date, noting his recent research with Felix Parra-Diaz, head of the Lab’s Theory Department, and Xu Chu, a graduate student, on whether plasma confined in a fusion system known as a stellarator could have ballooning modes that are explosive under specific conditions.

“People say stellarators are great because they don’t have disruptions,” Cowley said during the talk. Explosive ballooning modes are not as bad as disruptions, but stellarator designers might need to consider them.

Other mini-conference presenters from PPPL included:

• Associate Research Physicist Krish Bhutwala – “Measurements of Proton Stopping Power in Warm Dense Matter Approaching the Bragg Peak”
   
• Head of Digital Engineering Michael Churchill – “A Vision for Simulation-based, Multi-fidelity Digital Twins in Fusion Energy”
   
• Associate Research Physicist Kirill Lezhnin – “Laser Ion Acceleration From Concave Targets: Focusing, Scaling and Robustness Studies”
   
• Senior Physicist William Lee – “Finite Larmor Radius Effects on the Stepped Pressure Profile Equilibria Associated With Force Free State in Tokamak Plasmas”
   
• Research Physicist Timothy Stoltzfus-Dueck – “A Covering-Space-Like Approach to a Semi-differential Equation”
   
• Principal Research Physicist Hong Qin – “Oblique Photons, Plasmons and Current-plasmons in Relativistic Plasmas: Manifestly Covariant Theory and Topological Implications and Panel Discussion on Topological Plasma Physics”
   

Primed for media mentions

Of the 15 research topics selected by the conference for special promotion in the APS-DPP pressroom, four were from the Lab:

Stopping off-the-wall behavior in fusion reactors
New experimental results suggest that sprinkling boron into a tokamak could shield the wall of the fusion vessel and prevent atoms from the wall from getting into the plasma. A new computer modeling framework shows the boron powder may only need to be sprinkled from one location.

New AI models of plasma heating lead to important corrections in computer code used for fusion research
New artificial intelligence models for plasma heating can do more than was previously thought possible, not only increasing the prediction speed 10 million times while preserving accuracy but also correctly predicting plasma heating in cases where the original numerical code failed.

Researchers find clues to the mysterious heating of the sun’s atmosphere
New findings suggest a mechanism that could explain how black holes produce giant plasma jets that extend for thousands of light years.

Liquid lithium walls change the fusion-fueling game
Walls coated in liquid lithium can boost fusion efficiency by absorbing escaping plasma and helping refuel the plasma using high-energy beams.
 

Injecting plasma science into middle and high school curricula

The Lab was also involved in the conference’s Plasma Science Teacher Day, which included a plasma 101 workshop led by Shannon Swilley Greco, science education senior program associate. “This program is just one of the many ways the Lab works to support middle and high school teachers to address science standards in an innovative way using plasma,” Swilley Greco said. “We love to see teachers excited about cutting-edge research and bringing that knowledge back to their classrooms.”

PPPL staff presented interactive plasma and fusion demonstrations at the Fernbank Museum of Natural History and at three Title I schools in the Atlanta area. Teachers from Benjamin E. Mays High School participated in both the Plasma Science Teacher Day and the school visits, establishing a stronger connection.

“Between the museum and the school visits, we reached more than a thousand local students,” said PPPL’s Head of Science Education Arturo Dominguez.

Dominguez chaired the conference session “Science Education, Public Outreach, DEIA and Energy Justice.” This included talks by Greco and Abdel Majid Kassir, an associate research physicist in science education, on PPPL’s education and outreach activities. Majid Kassir also discussed his interest in plasma agriculture and his plans to grow a garden using plasma to enhance seed germination and plant growth at PPPL.