Neutron Capture in Evolved Red Giants: A Review

This review traces how our understanding of Low and Intermediate Mass Stars (hereafter LMS and IMS, respectively) evolved in time, in parallel with our knowledge of slow neutron-capture phenomena (the s-process). I shall focus in particular on the main component of this nucleosynthesis phenomenon, occurring in the above mentioned stars close to the end of their lifetimes. At that stage, they ascend the Asymptotic Giant Branch (AGB), where both hydrogen and helium shells exist, burning alternatively during the phases most relevant to our discussion (the so-called TP-AGB phases). I shall outline how neutron sources were discovered to be activated there and what observational constraints and nuclear measurements have taught us about the status of our theoretical models in this field of nuclear and stellar physics research.