Microscopic analysis of the 13C(α,n)16O and 13C(α,α)13C reactions

The C13(α,n)16O and C13(α,α)13C reactions are investigated through the generator-coordinate method. Two bands with marked α+ 13C structure are found in the O17 spectrum. Experimental candidates are proposed. The microscopic C13(α,α)13C cross sections are in fair agreement with experimental data. We show that the C13(α,n)16O cross section at stellar energies is strongly affected by the 1/2 2+ (6.36 MeV) weakly bound state. The astrophysical S factor below Ec.m.=0.3 MeV is therefore significantly enhanced with respect to the extrapolations used for astrophysical purposes. © 1987 The American Physical Society.