First Time Measurement of the 19F(p,x1) 16O Reaction at Astrophysical Energies: Evidence of Resonances Through the Application of the Trojan Horse Method

The F(p) O reaction is an important channel of fluorine destruction in H-rich environments as the outer layers of Asymptotic Giant Branch (AGB) stars. Measurements of the F(p) O reaction via the Trojan Horse Method (THM) have shown the presence of resonant structures not observed before. As a consequence, the reaction rate at astrophysical temperatures (about K) exceeds up to a factor 1.7 the one previously adopted. Here we present the result of an experiment in which THM was used to extract the Quasi-Free (QF) contribution of the H(FO)n reaction to the F(p) O channel, corresponding to the population of the first excited state of the O. Three resonances in the E energy region below about 500 keV have been observed. This result hints to an enhancement of the F(p, O destruction rate, with respect to what presently predicted.