β-Delayed Neutron Emission Studies of Neutron-Rich Palladium and Silver Isotopes

The rapid-neutron capture process (r-process) is attributed as the source of nearly half the elements heavier than iron in the solar system. The astrophysical scenario responsible is still unknown, making the specific astrophysical conditions uncertain. To gain insight into the r-process nucleosynthesis, uncertainties in the nuclear properties of the involved isotopes must be minimized. The r-process path traverses nuclei far from stability through many isotopes which have not yet been produced in the laboratory. This forces astrophysical models to rely heavily upon theoretical models of the involved nuclear physics. To help constrain parameters used in both astrophysical and nuclear models, an experiment was performed to measure properties of neutron-rich nuclei just below the N=82 shell closure. These nuclei are believed to be responsible for production of the A=130 peak in the solar r-process abundance pattern. The first measurements of β-decay half-lives and neutron branching ratios, P_n values, were performed for neutron-rich isotopes of palladium and silver.