Speaker
Description
One particularly challenging piece of the stellar nucleosynthesis puzzle is the origin of the heavy elements. Elements heavier than iron are mainly produced by neutron-capture reactions within the slow and rapid neutron-capture processes (s- and r-process, respectively). The r-process is believed to take place in environments characterized by high neutron densities, such that successive neutron captures can proceed into neutron-rich regions well off the β-stability valley. It involves a large number (typically five thousand) of unstable nuclei for which many different properties have to be determined and cannot be obtained experimentally. One of such fundamental properties concerns the radiative neutron capture reaction. The radiative neutron capture is traditionally estimated within the framework of the statistical Hauser–Feshbach formalism. This approach enables the calculation of nuclear level density and energy-averaged cross section, so it provides information about the reaction rate.
The present study aims to investigate the astrophysical neutron-capture reaction rates of nuclei far from the β-stability valley. First, a systematic comparison of theoretical predictions and β-Oslo data is performed for unstable nuclei. It is followed by an analysis of purely theoretical and experimental NLD levels for the neutron-rich nuclei, as well as an examination of how astrophysical temperatures affect the reaction rates. The sensitivity of the radiative neutron-capture cross section is then evaluated in various NLD energy ranges to determine the most effective NLD energy interval.
