Speaker
Description
Nuclear level densities (NLDs) and $\gamma$-ray strength functions (GSFs) provide key inputs to Hauser-Feshbach calculations and therefore influence reaction rate predictions used in nucleosynthesis modelling and applied studies. Previous Oslo method and complementary measurements in the palladium and cadmium mass region have highlighted characteristic features of the dipole response, including a low-energy enhancement that appears to weaken or vanish, as well as a possible pygmy dipole-resonance strength. These features can significantly affect calculated reaction rates, and therefore further understanding of the evolution of these features is key.
This project aims to extract the NLDs and GSFs of the silver isotopes $^{107}$Ag and $^{109}$Ag below the neutron separation energy using the Oslo method. The talk will present these preliminary results from the first round of a larger campaign of experiments at the Oslo Cyclotron Laboratory, with the goal of characterising features in a large selection of the silver isotopic chain. This campaign will extend Oslo method data to odd-$Z$ nuclei in the palladium-cadmium-tin mass region to investigate the evolution of the pygmy dipole resonance and the low-energy enhancement.