Indirect measurement of astrophysical 13C(α, n) 16O S-factors

The C-13(alpha, n)O-16 reaction is believed to be the main neutron source reaction for the s-process in asymptotic giant branch (AGB) stars. The astrophysical S-factors of this reaction have been determined based on an evaluation of the alpha spectroscopic factor of the 1/2(+) subthreshold state in O-17 (E-x = 6.356 MeV) by using the C-13(B-11, Li-7)O-17 alpha transfer reaction. Our result confirms that the 1/2(+) subthreshold resonance is dominant for the C-13(alpha, n)O-16 reaction at low energies of astrophysical interest.