Nucleosynthesis in TP-AGB stars and the production of 19F

Abstract

Low-energy resonances in the reaction 18O(α,γ) have been measured using a highly efficient γ ray coincidence detector system. These resonances dominate the reaction rate for temperatures typical for TP-AGB stars (0.1–0.3 GK). Preliminary results reduce the reaction rate by up to a factor of three at these temperatures. While this leads to an enhancement of the fluorine production in TP-AGB stars, it is not sufficient to explain the observed fluorine abundances in the surface of red giants.