New Tools for Radiative Neutron Capture in Stars and on Earth

East Texas A&M University, Commerce TX

Investigators

Abstract

Neutron capture in stars leading to the formation of heavy elements, as well as nucleon induced fission, are at the forefront of nuclear physics research. Because the neutron lacks charge, reactions with free neutrons are very difficult, and popular tools such as deuteron stripping (d,p) reactions are often used instead. The neutron inside the deuteron is bound and its energy, momentum, and angular momentum do not directly relate to the same quantities for a free neutron. Hence, the development of advanced (d,p) theory is critical for the success of many experimental programs at existing and future radioactive beam facilities. The overarching objective of this project is to advance the theory of deuteron stripping reactions leading to bound states and resonances, providing reliable connections between (d,p) reaction cross sections and the corresponding (direct or resonant) neutron capture cross sections on unstable nuclei. In this project the investigators will develop publicly available computer codes that will aid in the interpretation of low-energy experiments at radioactive beam facilities. Simple transfer reactions such as deuteron stripping (d,p) reactions carry many of the basic features of rearrangement reactions induced by heavier nuclei. They provide a unique tool for extracting nuclear information for neutron capture identified as one of the crucial inputs needed for nuclear astrophysics and applied physics studies, such as in advanced fuel cycles, nuclear energy and nuclear safety applications, and nuclear stockpile stewardship. Advanced reaction theory is the key to connecting (d,p) cross sections to neutron capture cross sections. This project is devoted to advancing low-energy reaction theory. The investigators will focus on obtaining accurate solutions of the generalized three-body Faddeev integral equations including explicitly the Coulomb interaction between nuclei. This project will provide training opportunities for students, who will have the chance to work on cutting-edge theoretical and computational developments of great importance for the future of nuclear physics.