The Enge Split-Pole Spectrograph at the University of Notre Dame

Abstract

Nuclear reactions play a crucial role in determining the nucleosynthesis that occurs in astrophysical events. The rates of many reactions that significantly impact certain nucleosynthesis processes can not be currently measured via direct means. These reactions must be constrained in another manner, such as determining the level energies and other structure properties of the compound nuclei. In order to measure level energies of nuclei relevant to nuclear astrophysics, the Enge split-pole spectrograph has been installed and commissioned at the University of Notre Dame’s Nuclear Science Laboratory. The first scientific measurement has also been performed. Structure properties of 58Cu were measured via the reaction 58Ni(3He,t)58Cu to provide the first experimental constraint of the 57Ni(p,γ)58Cu reaction rate, which impacts the production of of 44Ti, 57Fe, and 59Ni in core-collapse supernovae. Preliminary analysis of this measurement confirms the level energies of states in 58Cu that could lead to significant resonances in the 57Ni(p,γ)58Cu reaction rate, while suggesting the presence of additional states that have not been previously observed but could also lead to significant resonances.