Analysis of the dosimetry cross sections measurements up to 35 MeV with a ⁷Li(p,xn) quasi-monoenergetic neutron source

To improve the status of the dosimetry reaction data above 20 MeV, the activation cross sections on Bi, Au, Co and Nb have been measured at the NPI/Řež cyclotron facility with a quasi-monoenergetic p-⁷Li neutron source. The present work comprises the computational analysis of this experiment. It includes the Monte-Carlo simulation of the experimental set-up with the MCNPX code and relevant cross section data for proton and neutron induced reactions to predict the energy differential neutron flux in the irradiated foils. This approach has been validated against p-Li neutron spectra measured by different techniques. By making use of the modified unfolding code SAND-II, the dosimetry cross sections have been derived from the detected γ-ray activities. This has brought the new experimental results in the neutron energy domain between 18 and 35 MeV with estimated uncertainty at the level of 10%. They were used for validation of the activation (EAF, IEAF, IRDF) and the general purpose (ENDF) cross section files.