Analysis of the impact of the ²⁰⁴Tl neutron capture cross section on the s-process only isotope ²⁰⁴Pb

Abstract

In the study of the slow (s) process of nucleosynthesis branching nuclei become of particular interest. These nuclei have half-lives of the order of 1-100 years, and in the stellar environment their decay rate can compete with the neutron capture rate, which effectively leads to a split of the s-process path. Due to the dependence of the decay and the neutron capture rates on the the physical conditions -temperature and neutron density-of the nucleosynthesis environment, variations in these conditions lead to a change in the abundances of the immediately following nuclei. A very interesting branching point is the s-process only 204Tl, which decays to 204Pb. In this work we show how the capture cross section of 204Tl is a key nuclear input which, in addition to being crucial in fixing the ultimate 204Pb s-process abundance, makes the latter sensible to the temperature and neutron density of the stellar environment where the s-process takes place.