Betty Tsang, professor of nuclear science at FRIB, has been selected as the 2025 recipient of the American Chemical Society’s (ACS) Glenn T. Seaborg Award for Nuclear Chemistry. Sponsored by the ACS Division of Nuclear Chemistry and Technology, the Glenn T. Seaborg Award honors outstanding research in nuclear and radiochemistry or its applications.
Tsang was recognized for her contributions to studying the equation of state of dense nuclear matter and neutron stars, the production of unstable nuclei, and the dynamics of heavy-ion collisions. Equation of state describes matter in specific conditions, and how its properties change with density. Solving equation of state for a wide range of settings helps researchers understand the strong nuclear force’s effects within dense objects, like neutron stars, in the cosmos.
Throughout her career, Tsang has used nuclear collisions to understand the nature of nuclear matter created in the collisions of nuclei and neutron stars. One focus of Tsang's research is on the density dependence of the equation of state of asymmetric nuclear matter, using rare isotope beams and targets with extreme neutron and proton compositions. Tsang collides different nuclei to increase or decrease the fraction of the neutrons in the nuclear matter that is created. By focusing on “head-on” collisions and increasing their velocity, she increases the maximum densities of this nuclear matter to create densities and temperatures comparable to those achieved in the collisions of neutron stars. Her experimental results are especially timely, arriving in the wake of significant recent astronomical observations.
“In 2017, the merger of a binary neutron star system, GW170817, was detected, creating a lot of excitement in nuclear astrophysics,” Tsang said. “As two neutron stars draw near to each other, tidal forces cause them to deform. Scientists can measure these deformations through the gravitational waves emitted during the merger—waves that traveled 270-million light years to reach Earth. By analyzing these signals, which last about 100 seconds, we can deduce the reactions of neutron stars to pressure, temperature, and density.”
Observations that use optical and X-ray telescopes further enhance our knowledge of the equation of state of nuclear matter at extreme densities found in neutron star outer cores.
To complement astronomical observations, Tsang and her collaborators have analyzed experimental results from nuclear collisions over the past 20 years to determine the sensitivity of each experiment to different density ranges. By incorporating these results with astronomical data, they can extract the nuclear equation of state across a wide range of densities. This equation allows scientists to calculate neutron star properties, such as the radii of neutron stars of about 13 kilometers. The radii appear independent of the star’s mass, from one to two solar masses.
Tsang’s work also has practical applications. At Michigan State University’s High-Performance Computing Center, Tsang and her colleagues run transport simulations of nuclear collisions, which are used to help design radiation shielding for reactors, accelerators, and space missions. This research also has applications in medicine, particularly in optimizing radiation therapy doses.
Tsang has carried out experiments at accelerator facilities around the world. Much of her low-energy work, however, was performed at the National Superconducting Cyclotron Laboratory (NSCL), the predecessor to FRIB. More recently, she conducted experiments in Japan while awaiting the start of the FRIB operation.
Tsang earned her PhD in chemistry from the University of Washington, where she studied under Robert Vandenbosch, the 1981 recipient of the Glenn T. Seaborg Award.
“It is bittersweet that I received news of this honor just days after learning of my PhD advisor’s passing,” Tsang said. “Without the work of the innovative physicists who came before me and my collaborators, our efforts would not be possible. It’s through their hard work and groundbreaking discoveries that we are able to make an impact in nuclear science.”
In addition to her research, Tsang is an American Physical Society (APS) Fellow and a recipient of the Heinz-Pagels Human Rights Award. She has served as chair of the APS Committee on International Freedom of Scientists and the MSU Women’s Advisory Committee to the Provost.
“Congratulations to Betty on receiving this esteemed award,” said FRIB Scientific Director Alexandra Gade. “Her groundbreaking work involving the study of complex nuclear reactions in the laboratory not only enhances our understanding of the fundamental properties of nuclei but also gives us a glimpse of the properties of neutrons stars. This recognition is a testament to her dedication to science and the impact of her work.”
Tsang will be presented with the Glenn T. Seaborg Award at the ACS Spring 2025 meeting on March 25 in San Diego, California.
Michigan State University (MSU) operates the Facility for Rare Isotope Beams (FRIB) as a user facility for the U.S. Department of Energy Office of Science (DOE-SC), with financial support from and furthering the mission of the DOE-SC Office of Nuclear Physics.
The U.S. Department of Energy Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of today’s most pressing challenges. For more information, visit energy.gov/science.