R-process 130Cd Waiting Point

Abstract

Most of the elements heavier than Fe in the universe were produced by the so-called r-process. Its mechanism is based on a rapid neutron capture by the nuclei, so that the neutron capture rates are much faster than those of β -decay. When r-process reaches nuclei with magic neutron numbers, the neutron separation or binding energies increase and the process slows down, it has to wait for several β decays to produce heavier nuclei. These magic nuclei are the waiting points. Information about r-process are steel missing and it requires knowledge of the nuclear structure of the neutron rich nuclei. However, the nuclear properties of these nuclei are not sufficiently well understood due to the experimental difficulties in their production. The A=130 isobars with N=82 present one of the most interesting waiting points, because of their positions far from β stability and near the doubly magic 132Sn core, for which theoretical and experimental studies give important information about beta decay half-lives. In this context, we focus on the study of even-even 130 Cd waiting point nuclear properties. We have performed some spectroscopic calculations for energetic spectrum, β -decay half-life evolution in terms of temperature, using recent experimental data, by means of Oxbash nuclear structure code. The getting spectrum is in a reasonably agreement with the available experimental data. However, the calculated β-decay half-life for the studied waiting point is short in comparison with the experimental one.