Einteilchen-strahlungsübergänge im optischen modell des atomkerns

Abstract

Using the “distorted wave approximation” and employing for the nuclear interaction a complex square well potential, the single particle contribution to the radiative capture of neutrons incident on a medium weight nucleus is calculated. Numerical results are obtained for the upper end of the γ-spectrum, d σ(n, γ)/d E γ , for an incident energy of 20 MeV, and for the integrated cross section, σ(n, γ)( E n), in the energy region 10 MeV ≦ E n ≦ 20 MeV. These results agree fairly well with experimental data on (p, γ)-reactions, available in this energy region (figs. 1, 5 and 6), and a closer agreement of the integrated cross sections is obtained by adding to the single particle part the compound nucleus contribution for the process in question. The radiation from compound nucleus states contributes a non negligible amount up to about 15 MeV incident energy. The presence of an absorbing part in the potential does not change the order of magnitude of the cross section compared to the value obtained in a real potential, up to an absorption strength of V 1 = 10.5 MeV.