Measurement of leakage neutron spectra for aluminium with D-T fusion neutrons and validation of evaluated nuclear data

Abstract In the integral benchmark experiment presented here, an aluminium (Al) slab sample (300 mm × 300 mm × 100 mm) was irradiated with Deuterium-Tritium (D-T) fusion neutrons. The neutrons leaking from the sample were detected by a BC501A organic liquid scintillator through the time-of-flight (TOF) method; the neutron energy spectra were derived from the as-obtained TOF curves by considering the detector efficiency. For comparison, some leakage neutron spectra were also simulated by combining a Monte Carlo neutron transport code with evaluated nuclear data from the ENDF/B-VIII.0, JENDL-4.0 and CENDL-3.1 libraries. All the calculated values agreed with the experimental data within 10%, except for a few energy ranges. The values predicted using the ENDF/B-VIII.0 library were lower and higher than the measured ones at below and higher above 4 MeV, respectively; the data based on the CENDL-3.1 and JEDNL-4.0 libraries exhibited some larger differences in the 9.5–12 MeV range at 120 ∘ . The possible causes of these discrepancies are also discussed.