Direct neutron capture in light nuclei

The consistent direct-semidirect capture model (CDSD) is applied to the keV energy region where the direct process is dominant. We study the influence of the correction of the form of the direct term due to a difference ΔV in the potentials used to describe the scattering and the bound single-particle state of the captured neutron. The sensitivity of the cross sections on the semidirect capture mechanism in this energy region is examined as well. We consider the 12C(n,γ) and 16O(n,γ) processes which are of astrophysical interest in the energy region of the incoming neutrons between 10 keV to 0.6 MeV where good experimental data exist. It is shown that both corrections are negligible for capture to the states where s-waves are not involved. For s-wave capture to the p-orbits the ΔV correction of the direct term is important. The data do not support the contribution of the semidirect term as described by the model in the energy region studied. (orig.)