Determination of double-differential neutron cross sections of elemental chromium in the energy range from 8 MeV to 14 MeV using a DD neutron source

In neutron scattering measurements using a DD neutron source, above an incident neutron energy of about 8 MeV, the spectra of the scattered breakup neutrons and of the inelastically scattered monoenergetic neutrons superimpose each other. The disturbing fraction of the breakup scattering neutrons can be subtracted after having been calculated by a realistic Monte Carlo simulation of the scattering geometry and processes. The data for such a calculation are checked and adjusted using an additional pure breakup neutron source based on the 4He(d, np)4He reaction. By proper subtraction of the breakup fractions, double-differential cross sections can be obtained for neutron emission energies down to 1.5 MeV. This procedure is described for elemental chromium. The results are compared with those obtained using a monoenergetic 14 MeV neutron source and with the ENDF/B-VI evaluation. Conclusions for further improvements are discussed. (orig.)