Using Fast Neutrons to Explore Nuclear Structure

Research in nuclear structure at the University of Kentucky is focussed on related topics in nuclear spectroscopy, neutron-induced reactions, and neutron scattering. Most of this work will utilize fast neutrons produced at the University's accelerator facility and the unique gamma-ray and neutron detection capabilities of this laboratory; complementary, collaborative research with colleagues at several other institutions is in progress and these collaborations are expected to continue. Neutron scattering experiments are primarily oriented toward exploring multiphonon vibrational excitations of the quadrupole and octupole types in nearly spherical nuclei, examining the separate roles of magnetic and electric dipole transitions in collective excitations, defining the roles of protons and neutrons in collective modes, and understanding nuclear shell structure and the nature of nuclear shape transitions. The characterization of phonon-coupled excitations of mixed-symmetry states, a new type of collective mode, in weakly deformed nuclei will receive a high priority. A new direction is the use of higher-energy neutrons to produce final nuclei that are not readily accessible with charged-particle fusion-evaporation reactions. Lifetime determinations with the Doppler-shift attenuation method and gamma-gamma coincidence measurements, for which the methodologies have been developed in our laboratory, will play crucial roles in many of these studies. Neutron scattering studies, which aid in elucidating the differences between neutron excitation and other probes, will complement studies of the microscopic basis of collective excitations. Carefully selected studies in other areas, e.g., nuclear astrophysics and the properties of light nuclei, which are particularly appropriate to the capabilities and facilities at the University of Kentucky accelerator laboratory will be pursued. Education continues to be an important component of all activities in our laboratory, and efforts to provide an excellent working environment for undergraduate, graduate, and post-graduate education in nuclear science at the University of Kentucky will be made.