Elucidating Nuclear Structure with Fast Neutrons and Complementary Techniques

About This Grant

The atomic nucleus, composed of protons and neutrons, is about 100,000,000,000 times smaller than is visible by the human eye. Because it is so small, it is not possible to take an ordinary photograph to investigate its basic properties, shape, and structure. Other methods must be employed to “develop a picture” of the nucleus. While we often think of nuclei as spherical in shape, more often they are deformed spheres like an onion or a football. To investigate these structures, the team at the University of Kentucky Accelerator Laboratory uses a Van de Graaff accelerator and a nuclear reaction to produce neutrons, which they scatter from nuclei of interest. The neutron scattering process produces gamma rays that can be used to construct an image of the nucleus. These images contribute to understanding how protons and neutrons interact within the nucleus to form matter in the universe. In addition, students at all levels are provided with opportunities to participate in these studies. Program participants receive hands-on experience and emerge as well-trained nuclear scientists who are capable of important contributions to national energy, medical, and security needs. The University of Kentucky Accelerator Laboratory (UKAL) specializes in producing nearly monoenergetic neutrons. Employing this probe for inelastic neutron scattering studies (INS) yields a wealth of information for nuclear structure including the population of excited states which are often inaccessible with other methods, and the measurement of level lifetimes via the Doppler-shift attenuation method. The primary goal of this work is to provide detailed spectroscopic data that lead to the understanding of the fundamental properties of atomic nuclei. The team at UKAL will continue to investigate open questions about shape coexistence and the onset of collectivity in nuclei within selected isotopic chains as well as study isotopes of interest for neutrinoless double-beta decay, 0νββ. The researchers will also perform complementary measurements in collaboration at other facilities and work together with theorists to provide interpretations of the data obtained. Perhaps the largest advantage of university nuclear laboratories is the ability of learners at all levels to gain hands-on experience with all aspects of the experimental process. These laboratories such as UKAL play a critical role in workforce development as students emerging from them will be well-trained members of the next generation of nuclear scientists necessary for meeting national needs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.