Our research program concentrates on fundamental aspects of the nucleus as a quantum many-body system. Probes of nuclear properties can answer open questions relating to the microscopic behavior of quantum systems, as well as the macroscopic behavior of stars.
Research in nuclear structure is focused on studies of dynamics, deformations, and bulk nuclear properties. The latter includes the study of “giant resonances” to determine the incompressibility of nuclear matter, which plays an important role in determining the properties of matter at the core of neutron stars.
A pioneering focus in the Nuclear Science
Laboratory has been the development and application of short-lived
radioactive beams, and the associated study of the structure and reactions
of nuclei at the very limits of particle stability. This includes
investigations of the recently discovered “neutron halo” nuclei, exotic
systems in which a cloud of nearly pure neutron matter at very low
density surrounds a normal nuclear core.
A major research initiative for our laboratory is understanding the origin of the elements in the universe. Measurements of nuclear reaction rates and decay processes at stellar temperatures and densities comprise a strong part of the experimental effort in nuclear astrophysics. The goal is to understand the fate of matter in our universe. Research is directed towards simulating stellar nucleosynthesis in the laboratory, understanding late stellar evolution, explosive nucleosynthesis in novae and supernovae, and explaining the origin of the very high luminosity observed in stellar x-ray bursts.
Developing Accelerator Mass Spectrometry techniques for astrophysics is another research focus of our laboratory. Accelerator Mass Spectrometry has traditionally been used to detect environment tracers at or below their natural abundance level (10Be, 14C, 36Cl,…). Its main attribute is its power to accelerate and analyze ions of radioactive nuclei with extremely high sensitivity. Many aspects of this powerful technique can be used for research involving radioactive-beam physics, as well as the study of low cross-section nuclear reactions which are important in stellar evolution. That is the case where counting rates and voltage are very low and there are high isobaric backgrounds.
The major experimental facilities in the laboratory include an FN Tandem accelerator that can provide up to 11 MV terminal voltage for the acceleration of light and heavy ions; the Twinsol radioactive beam facility, based on two coupled 6 Tesla-meter superconducting solenoids for the focusing of the radioactive beam particles onto a target; a 4 MV KN and a 2 MV JN Van de Graaff accelerators capable of delivering the intense, low-energy beams necessary for recreating stellar conditions in the laboratory; a number of clover and Compton-suppressed Ge detectors for gamma-ray spectroscopy measurements; and a superconducting solenoid system for weak interaction studies.
In addition to the high level of activity within the nuclear laboratory, the nuclear group's research is complemented by experiments done at various national facilities including the superconducting cyclotron at Michigan State University and accelerator facilities at the Argonne, Berkeley, Oak Ridge, Los Alamos, and Thomas Jefferson National Laboratories. On the international scene, Notre Dame scientists also utilize the High Flux Beam Reactor at Grenoble, France, the GANIL facilitiy in Caen, France, the ISOLDE radioactive ion facility at CERN, Switzerland, and various accelerator facilities in Germany, Belgium, France, India, Italy, the Netherlands, and Japan.
We also have a lively interdisciplinary program in radiation chemistry, bio-mechanics, materials testing, and elemental analysis of archeological samples in addition to our basic science interests. Elemental analysis in archeological samples is a new program with the University of Notre Dame Snite Art Museum using the PIXE technique. We also pursue research with two industries in testing new detectors and determining the durability of artificial human body components.