Low-Energy, High-Impact Physics

Triangle Universities Nuclear Lab Celebrates 50 Years
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Nov 2, 2015

The identity of this region of North Carolina as a “Research Triangle” was still more of a concept than a reality in 1965 when the U.S. Atomic Energy Commission gave the three universities $2.5 million to build a cutting-edge laboratory to explore the Nuclear Age.

Borrowing some of its identity from the newly minted Research Triangle Park just a few miles away on Highway 54, the launch of the Triangle Universities Nuclear Laboratory was front page news throughout the region.

Duke professor Henry Newson had succeeded -- on his third try -- in securing funding for a 15-MeV tandem Van de Graaff accelerator and a 15-MeV cyclotron. His creative twist was the idea of using the cyclotron to inject a particle beam into the Van de Graaff to cost-effectively double the beam energy. Scientists at TUNL called the combination the cyclo-graaff.

The other magic of the third funding attempt was the idea to include UNC and NC State in the proposal, said Eugen Merzbacher, a professor emeritus at UNC who died in 2013. “Henry had this brilliant idea to combine the three universities.”

Merzbacher helped write the successful proposal, as did Worth Seagondollar, who was chair of the physics department at N.C. State. Each university would supply faculty members and graduate students to conduct research using the equipment.

Fifty years later, the agreement stands.

The cyclotron is gone and the lab has had to change its goals with the times, but it still brings more than $7 million of research funding into the Triangle each year. It outlived the AEC, which became the Department of Energy. DOE’s Office of Nuclear Physics is still the major funder, but there is support from other agencies as well, including the National Nuclear Security Administration, the National Science Foundation, and the Domestic Nuclear Detection Office of the Department of Homeland Security.

The TUNL lab has produced 286 Ph.D.s from all three schools, some of whom are returning the weekend of Nov. 6-8 to celebrate and get caught up.

Construction of the cyclo-graaff lab, located behind the Duke physics building on West Campus, was partly supported by a grant from the North Carolina Board of Science and Technology. 

Russell Roberson, professor emeritus and a former TUNL director, arrived at Duke in 1963. At the time, the Duke Physics department had two small Van de Graaff accelerators -- one rated at an energy of 4 MeV and another rated at 3 MeV -- but Newson wanted a bigger accelerator for bigger experiments.

“Because of his work on the Manhattan Project, Newson understood how many people could effectively use a big facility like the tandem Van de Graaff,” Roberson said. “He knew Duke couldn’t provide that many people. But by dividing it up among the three universities, we were able to establish a very significant faculty presence with a large number of graduate students and make it one of the top accelerator and nuclear facilities in the country.”

TUNL early 1990s
Jim Koster (NCSU), Scott Wilburn and Paul Huffman in the Tandem
Van De Graaf control room, circa early 1990s.

Originally, the focus of TUNL was nuclear structure. Newson, who directed the lab from 1968 until his death in 1978, used a high-resolution neutron beam to study the atomic nucleus. Later, Duke professor Edward Bilpuch modified the equipment to produce a proton beam, which he and colleagues used in a series of well-known experiments to study isobaric analogue states of the nucleus with ultrafine energy resolution.

Parts of the massive Van de Graaff that arrived in 1966 are still being used by TUNL physicists, but over the years, the lab has broadened its focus, said current director, Duke professor Calvin Howell, who did his graduate work as a Duke student at TUNL in the 1980s.

The lab’s evolution often followed the interests and technical innovations of faculty members. For example, when UNC professor Tom Clegg built a polarized ion beam at TUNL in 1986, other faculty members and students caught his enthusiasm and used it for their own experiments.

Driven by a free electron laser housed in a separate building behind the original TUNL, that polarized beam is now known as the HIGS (high intensity gamma-ray source), and it’s the world’s most intense polarized gamma-ray beam.

“That’s been the history of TUNL—new people come in with new ideas and new technology and techniques, and they don’t just hoard those things for themselves,” Howell said. “The collaboration and the synergy between faculty members works beautifully. We don’t have institutional boundaries.”

Today, TUNL physicists are pushing scientific frontiers in several areas, including studying strong interaction physics to better understand the structure of nuclei and nucleons (protons and neutrons); modeling nuclear reactions in stars; and delving into the fundamental nature of neutrinosto discover whether these chargeless particles serve as their own anti-particles and how they may have played a role in the processes that generated the visible matter in the universe.

But TUNL leaders all agree that one of the lab’s most important contributions has been educating the next generation of scientists. (Learn more about Duke's TUNL alumni.)

“We’ve continued to be one of the more significant laboratories in the country in terms of producing students,” Roberson said. “Many of our graduate students go in industry and the national labs and universities. At one time, there were 35 graduates from TUNL working at Los Alamos National Lab.”

“The record speaks for itself in the outstanding scientists we have produced at the Ph.D. level,” Howell said. “In the last 15 years, we’ve also put considerable effort into creating opportunities for undergraduates.”

The NSF-funded Research Experience for Undergraduates (REU) program supports 10-12 undergraduates from around the country each summer to work and learn at TUNL. The lab also collaborates now with Duke’s high-energy program to allow REU students to spend the summer at the Large Hadron Collider at CERN in Switzerland.

There are other examples of universities that tried to create shared physics laboratories but were not able to work together as a team to make it happen, according to Steve Shafroth, who came to UNC and TUNL in 1967.

“TUNL is such a unique thing, with the three universities collaborating like that and staying friends,” Shafroth added with a laugh. “You know, with the basketball rivalry and all so strong.”

For More TUNL History, as told by a series of champagne bottles, visit the Duke Research Blog.


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