First Measurement of the Neutron Capture Cross Sections of Stable Germanium Isotopes

Nearly half of all elements heavier than iron are created during the s-process. The s-process can be broken into main and weak components. Because the weak s-process occurs out of statistical equilibrium and the cross sections involved are small, each isotope serves as a bottleneck. Therefore the neutron capture cross sections radically affect the abundance of all isotopes downstream. Almost all stable Germanium isotopes lie along the weak s-process path and yet no neutron time-of-flight measurements of their cross sections have been made. In January 2018, the Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos Neutron Science CEnter (LANSCE) was used to measure the neutron capture cross sections of 70Ge, 72Ge, and 73Ge. A follow up experiment to measure the cross sections of the remaining stable Germanium isotopes at the same facility is planned to occur in the near future. The results of these experiments, the astrophysical impact, and future work based on these results will be discussed.