Fast neutron spectra measurement in a copper using a 252Cf standard neutron source

The presented paper focuses on the measurement of fast neutron leakage spectra in the copper assembly using an intense standard 252Cf(sf) source. The neutron spectra were measured by a stilbene organic scintillation detector and compared with MCNP6.2 calculations using copper nuclear data from the ENDF/B-VIII.0, ENDF/B-VII.1, JEFF-3.3, JEFF-3.2, JENDL-4.0 and CENDL-3.1 libraries in the energy range of 1–10 MeV. Discrepancies appear in the intermediate neutron energy range between experiment and calculation. The best agreement with an experiment was achieved using ENDF/B-VIII.0 library in the region of 1–4.5 MeV. In the region of 4.5–10 MeV, the best agreement was achieved using JENDL-4.0 or CENDL-3.1 library. The largest discrepancies in the whole energy range were found for calculations involving JEFF-3.3 copper evaluations.