Direct neutron capture for magic-shell nuclei.

In neutron capture for magic-shell nuclei the direct reaction mechanism can be important and may even dominate. As an example we investigated the reaction {sup 48}Ca({ital n},{gamma}){sup 49}Ca for projectile energies below 250 keV in a direct capture model using the folding procedure for optical and bound state potentials. The obtained theoretical cross sections are in agreement with the experimental data showing the dominance of the direct reaction mechanism in this case. The above method was also used to calculate the cross section for {sup 50}Ca({ital n},{gamma}){sup 51}Ca. {copyright} {ital 1996 The American Physical Society.}