A new experiment for the determination of the F-18(p, alpha)) reaction rate at nova temperatures

The F-18(p, alpha)O-15 reaction was recognized as one of the most important for gamma ray astronomy in novae as it governs the early 511 keV emission. However, its rate remains largely uncertain at nova temperatures. A direct measurement of the cross section over the full range of nova energies is impossible because of its vanishing value at low energy and of the short F-18 lifetime. Therefore, in order to better constrain this reaction rate, we have performed an indirect experiment taking advantage of the availability of a high purity and intense radioactive F-18 beam at the Louvain La Neuve RIB facility. We present here the first results of the data analysis and discuss the consequences.a (Author)