Low-energy F18(p, α)O15 cross section measurements relevant to nova γ-ray emission

During nova outbursts the decay of F-18 is the main source of gamma-ray emission at and below 511 keV. In spite of much experimental effort, the quantity of F-18 synthesized still suffers from large uncertainties which arise mainly from the F-18 p, a)O-15 reaction cross section at low energies. We report here on a new direct measurement carried out at the Louvain-la-Neuve RIB facility of Louvain-la-Neuve using an isobarically pure F-18 beam impinging on a thin polyethylene target. Cross sections down to a center-of-mass energy of 400 keV have been obtained and the results together with previous experimental data were compared to R-matrix calculations. The effect of the relative contribution of the two low-lying 3/2(+) resonances as well as the sensitivity of the calculations to the R-matrix radius is studied in detail.