Measurements and calculations of neutron leakage spectra from lead slabs irradiated with 14 MeV neutrons

摘要

Neutron leakage spectra through lead slabs with thicknesses of 0.05, 0.075 and 0.125 m were measured by using a proton recoil technique and a differentiation unfolding procedure. The measure-ments were performed on an absolute basis. The results were compared with the prediction of Monte Carlo calculations by using the MNCNP-4A code and pointwise cross-sections from ENDF/B-IV and ENDF/B-Vi data fiels. The calculations employing ENDF/B-Vi data show good agreement with the experimental results, with the exception of the energy region between 5 and 10 MeV, where an under-estimation of up to 29