Measurement of the cross section of 12C(α, γ)16O using the recoil mass separator ERNA

The reaction 12C(α, γ)16O plays a key role in determining the C/O ratio in the stellar core at the end of helium burning, which in turn influences the further evolution and nucleosynthesis. The determination of the cross section at the relevant astrophysical energy Ecm=0.3 MeV, which is of the order of 10−17 b, requires extrapolation of the S factor determined from data collected with high precision and accuracy at higher energy. A new experimental approach has been undertaken in order to study this reaction for the first time by the direct detection of the 16O nuclides using the recoil mass separator ERNA.