Cross Sections for the Production of 8- to 20-MeV Photons

Information on the production of high-energy photons, due to (n, γ) reactions for neutron energies up to ∼20 MeV, may be useful in reactor technology. Use of theoretical estimates is required to make up for the lack of measured data. For this purpose, the semidirect capture model is used. The model is refined by introducing a volume form for both the real and the imaginary parts of the nucleon-nucleus coupling interaction and its validity checked on available experimental (n, γ) data. The effective cross sections for the production of 8- to 20-MeV photons are calculated for the ¹⁴⁰Ce(n, γ) and ⁹³Nb(n, γ) reactions considering three different distributions of 4- to 15-MeV incident neutrons.