Validation of ENDF/B-Ⅷ thermal neutron scattering data of heavy water by differential cross section measurements at various temperatures

摘要

Temperature-dependent thermal neutron differential scattering cross sections for heavy water (D2O) were measured using a triple-axis spectrometer at the National Research Universal reactor located in Chalk River, Canada. The measurements were performed at temperatures from 22 to 85 degrees C and at atmospheric pressure, with incident neutron energies from 16 to 44 meV and scattering angles from 10 to 110 degrees. The temperature range in the measurements covered the common D2O moderator conditions (65-70 degrees C and 1 atm pressure) in pressurized heavy-water reactors. The measured results were compared with the D2O data libraries from the ENDF/B-VII.1 evaluation and the recently released ENDF/B-VIII.0 evaluation. The experimental results indicate significant improvements in the new release compared to the previous ENDF/B-VII.1 release. (C) 2019 Elsevier Ltd. All rights reserved.