Indirect study of 13C(α,n)16O

The reaction 13C(α,n)16O is considered as the main neutron source for s-process in low-mass asymptotic giant branch stars. At low energies of astrophysical interest, the contribution of the subthreshold state 6.356 MeV of 17O to the 13C(α,n)16O cross section should be taken into account. However, the results of previous studies of this contribution lead to different conclusions. Hence, we investigated the effect of this resonance on the astrophysical S-factor through a new precise measurement of the alpha spectroscopic factor, S α, of the 6.356 MeV state using the transfer reaction 13C(7Li,t)17O at two different incident energies. The measured angular distributions and the obtained spectroscopic factors will be presented as well as their impact on C(α,n)16O cross section and reaction rate. © 2008 American Institute of Physics.SCOPUS: cp.p