Sweeping out the Van de Graaff accelerator in the early days. As a Center of Excellence for Nuclear Physics, TUNL has relied on countless hands like these for 60 years — and counting. (Duke University Archives)
Triangle Universities Nuclear Laboratory is Self-Sustaining at Sixty
Quietly tucked behind Physics on West Campus, an unassuming concrete building conceals one of Duke’s best-kept secrets. The brutalist austerity and lack of signage reveal little, yet beneath its asphalt parking lot sprawls a subterranean warren of thick-walled rooms that have borne witness to 60 years of nuclear physics research.
This hidden network is the Triangle Universities Nuclear Laboratory, TUNL for short, the brainchild of experimental nuclear physicist Henry W. Newson.
Joining the Department of Physics in 1948, Newson brought a career built upon milestones of the Manhattan Project. At Duke, he spent nearly two decades helping lay the groundwork for what would become TUNL. With support from the United States Atomic Energy Commission, and in close partnership with colleagues at the University of North Carolina Chapel Hill (UNC) and North Carolina State University (NC State), he helped transform a shared vision into a consortium of laboratories whose influence on nuclear physics research endures today.
Collaboration defined TUNL from the beginning, with Duke, UNC and NC State forming the original tripartite. North Carolina Central University (NCCU), long connected to TUNL through faculty and student involvement, formally joined in 2018.
Today, TUNL is a Department of Energy (DOE) Center of Excellence for Nuclear Physics — one of only four in the country — and grants roughly 8% of all U.S. doctorates in experimental nuclear physics yearly. For professor of Physics and TUNL’s interim director (and former director from 2006-2016) Calvin R. Howell, success boils down to two components: a shared mission among the consortium and a solid community.
“The shared mission is straightforward — explore the frontiers of nuclear physics while educating the next generation of experimental physicists,” he explains, “and fulfilling that mission demands not only expertise but also a suite of highly specialized facilities.”
The facilities
At the core of TUNL’s facilities are three laboratories: the Tandem Accelerator Laboratory, the Laboratory for Experimental Nuclear Astrophysics (LENA) and the High Intensity Gamma-ray Source (HIGS).
The Tandem Accelerator Laboratory houses the Van de Graaff Accelerator, which boosts charged ions to energies up to 10 million electron volts — about 85,000 times more energetic than charged particles accelerated by the output of a standard wall outlet — and sends them along several beamlines. Researchers use the beams to study nuclear reactions and nuclei involved in stellar processes, especially those too difficult to investigate at other facilities.
Operated by TUNL but housed in the adjacent Duke Free Electron Laser Laboratory, HIGS resembles an elongated racetrack. It directs a powerful laser at electrons accelerated to ultra-relativistic speed, i.e. greater than 99.9999% of the speed of light. When the light scatters off these electrons, it recoils to become highly precise energy-tunable and polarized gamma-rays — the part of the electromagnetic spectrum with wavelengths similar to that of photons emitted via di-excitation of nuclei. HIGS is the world’s most powerful source of its kind, delivering roughly 50 million gamma-rays per second to experiments in the energy range of 1 to 100 MeV.
LENA lives in the basement of the Physics building and is dedicated to exploring the nuclear reactions that drive stellar evolution and element formation. Its Electron-Cyclotron Resonance (ECR) accelerator creates the world’s most intense proton beams for nuclear astrophysics research, delivering nearly 2 milliamps (mA) of beam current at energies up to 230 keV. Currently undergoing an upgrade, LENA will soon be able to produce at least 20 milliamps of beam current, enabling researchers to replicate nuclear reactions occurring in the cosmos. The facility is complemented by a 2-MV Singletron accelerator — built specifically for LENA — that produces currents exceeding 2 mA and is the only accelerator of its kind in the world.
These three labs provide an unparalleled toolkit for nuclear physics research, giving scientists and students direct access to equipment and experiments that most only encounter at advanced national labs.
Taking advantage of the advantages
TUNL’s facilities are world-leading, but of equal distinction is its unmatched community of learners. Paul Huffman, department head and professor of Physics and Astronomy at NC State and part of TUNL, experienced the impact of community firsthand as a Ph.D. student at Duke. What sets TUNL apart for him is the access. Graduate students can work with any faculty member in the consortium, choose advisors across institutions and collaborate freely.
He explains that TUNL students can arrive in the morning, turn on the source, get the beam through the accelerator and if all goes well, be ready to collect data by the afternoon. This isn’t possible at large, national labs, where entire teams of operators run the accelerators and students never get the opportunity to “tinker with the system.”
“Because the scale at TUNL is different, our students can actually learn how the equipment works from the inside out, and that helps them land jobs quickly,” he shares. “TUNL students don’t just have strong theoretical and physics training, they also have the hands-on experience — and that is becoming increasingly rare.”
For Huffman, TUNL is still a place where collaboration and community are built into the daily rhythms of research. From the technicians to the director, everyone contributes to the shared mission, while the expertise, collaboration and respect within and across laboratories remains unbroken.
“It’s a place with a breadth of expertise mixed with humility, where you can walk in, talk to anyone and get things done together. It really does feel like home.”
For Art Champagne, professor of Physics and Astronomy at UNC, the TUNL home was a “big draw” when he accepted his current position at UNC. And he experienced the consortium’s strong sense of community while serving as TUNL’s first non-Duke-affiliated director from 2016-2021. “What makes TUNL special,” he says, “is that it’s more than the tools and facilities — it’s the people working together across universities who make the ideas that generate the experiments that lead to the discoveries.”
Being part of the consortium provides UNC researchers and students access to accelerators, specialized facilities and top-notch support staff — while also fostering an environment where new ideas can quickly attract critical mass and collaboration.
“In astro-nuclear structure work, students rely on accelerators maintained by TUNL’s expert support staff and on engineering expertise to turn ambitious — but sometimes impractical — physicists’ designs into functional, efficient systems,” Champagne explains. “This integration of engineering insight into the research process has been transformative for UNC, ensuring that ideas move from concept to reality with precision and scalability.”
Howell says that this level of seamless collaboration is no accident — it’s the result of the consortium’s long-standing commitment to the shared mission. TUNL is the place where common scientific questions naturally bring researchers together, even when their approaches differ. “As experimental scientists, we focus on questions that overlap, but we often pursue the answers in different ways,” he explains. “We recognize that each of us brings complementary technical expertise to TUNL, so we can lean on each other when we need things outside of our expertise.”
And as the only multi-university laboratory among the Department of Energy’s Centers of Excellence, TUNL provides all its students with a breadth of resources they simply couldn’t get anywhere else.
Mohammad Ahmed has been part of TUNL for 25 years and currently serves as an associate director. Recruited by Duke from Brookhaven National Lab, he transitioned to NCCU in 2011 where he is the dean of the College of Health and Sciences and professor of Physics and Mathematics. For Ahmed, TUNL’s impact on NCCU students has been life changing.
He shares the story of a student who was nearing graduation when a series of personal setbacks forced her to pause her studies. When she returned, the TUNL family ensured she had the support needed to regain momentum, from academic guidance and funding opportunities to an internship. Today, she is a lead engineer in her field of research and development.
“Her journey was shaped by persistence and sustained support, showing how transformative it can be when a student is met with opportunity, mentorship and room to grow,” Ahmed explains. “For students who are under-resourced or face significant headwinds such as family loss or financial strain — as well as the stigma that can come with hardships — TUNL can be their bridge to possibility.”
For the last sixty years, that bridge has been maintained by continuous investments that take many forms: from a $1.5 million award from the DOE to a 10-week summer program bringing undergraduates from across the country into nuclear and particle physic research, as well as partnerships that open TUNL’s labs to outside collaborators.
TUNL recently hosted teams from the University of Maryland, NASA’s Goddard Space Flight Center and the Naval Research Laboratory, who used the facility to validate the performance of prototype gamma-ray detectors for future NASA missions, such as the All-sky Medium Energy Gamma-ray Observatory (AMEGO). And researchers from Los Alamos National Laboratory are preparing a run at HIGS in the spring to test the performance of their gamma-ray dosage imaging detectors. Such work underscores TUNL’s enduring commitment to progress, a perspective that has guided the consortium since its founding.
“While it’s important to understand where we came from, we need to keep our eyes on the windshield and not the rearview mirror,” Howell shares. “As scientists, we should stay forward-thinking while managing what’s already on our plates, and that shared mindset is what has kept TUNL relevant for the past sixty years — and what will sustain it.”
