Influence of neutron-capture reactions on the nucleosynthesis of strontium

The astrophysical intermediate neutron-capture process (i process) has been reinvoked in recent years to describe stellar observations that cannot be explained by the traditional nucleosynthesis processes. Despite its success, significant uncertainties still remain including the exact astrophysical conditions and site, as well as the nuclear physics input. Available i-process models strongly underproduce the abundance of strontium (Sr) compared to observational data, while successfully describing neighboring elements, like yttrium (Y) and zirconium (Zr). This discrepancy has been attributed to nuclear physics uncertainties, specifically to the unconstrained reaction rate of the neutron-capture on the isotope krypton-88. Here we present an experimental investigation of this reaction and show that our result provides a possible solution to the aforementioned Sr underproduction in i-process models. Astrophysical models underproduce the element Sr in intermediate neutron density environments (the so called i-process). The authors investigate the nuclear reactions that produce Sr and find that the new experimental reaction rates help to bridge the gap between models and observations.