Looking Back at the First 50 Years of TUNL

Banner headlines—in one-inch tall type—shouted “Duke to Get Nuclear Lab” and “$2.5 Million Nuclear Lab to be Established at Duke.” The date was November 23, 1965, and the occasion was the funding of the Triangle University Nuclear Laboratory (TUNL) by the federal Atomic Energy Commission (AEC). The news was so big that an editorial cartoon in the Durham Morning Herald showed two farmers discussing the equipment that would be in the new lab. 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. In 1963 and 1964, Newson had submitted similar proposals to AEC from Duke alone, neither of which were funded.What made the third time the charm? Eugen Merzbacher, professor emeritus at UNC, says, “Henry had this brilliant idea to combine the three universities.” Merzbacher helped write the 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.Henry Newson’s brilliant idea is still fostering collaborations today among faculty and students from Duke, North Carolina State University, and the University of North Carolina at Chapel Hill—and now North Carolina Central University as well. Newson’s other creative twist was the idea of using the cyclotron to inject a beam into the Van de Graaff to cost-effectively double the beam energy. Scientists at TUNL called the combination the cyclo-graaff. Shortly after the proposal was funded, Newson came up with the idea of naming the lab the Triangle Universities Nuclear Laboratory, or TUNL, building on the name recognition of the newly minted Research Triangle Park. Construction of the cyclo-graaff lab, located behind the Physics building on West Campus, was partly supported by a grant from the North Carolina Board of Science and Technology. Newson served as director of TUNL from 1968 until his death in 1978. 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. Before coming to Duke in 1948, Newson had done stints at Oak Ridge, Hanford, and Los Alamos National Labs, and had worked on the Manhattan Project. “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 says. “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.” For many years, TUNL was funded solely by AEC, which later became the Department of Energy. Today, 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. Originally, the focus of TUNL was nuclear structure. Newson used a high-resolution neutron beam to study the 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. Over the years, TUNL has broadened its focus. The current director, Duke professor Calvin Howell, says TUNL’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. “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 says. “The collaboration and the synergy between faculty members works beautifully. We don’t have institutional boundaries.” Howell did his graduate work as a Duke student at TUNL in the 1980s. 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 neutrinos to 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. Parts of the Van de Graaff that arrived in 1966 are still being used by TUNL physicists, but newer machines have come online as well. One of these is the free electron laser known as the HIGS (high intensity gamma-ray source), housed in a separate building behind the original TUNL building. HIGS is now producing the world’s most intense polarized gamma-ray beams. As TUNL approaches its 50th anniversary, both Roberson and Howell say that one of the most important contributions of TUNL has been its role in educating the next generation of scientists. Roberson says, “We’ve continued to be one of the more significant laboratories in the country in terms of producing students. 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, helping provide a significant national defense to the country.” Howell says, “The record speaks for itself in the outstanding scientists we have produced at the PhD level. In the last 15 years, we’ve 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. Last year, TUNL began collaborating with Duke’s high-energy program to allow some of the 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. Shafroth says, “TUNL is such a unique thing, with the three universities collaborating like that and staying friends.” He adds with a laugh, “You know, with the basketball rivalry and all so strong.” Merzbacher agrees, saying, “TUNL is the only tripartite lab in the country. There’s nothing else like it.” Mary-Russell Roberson is a freelance science writer who lives in Durham.