The benchmark experiment on slab iron with D-T neutrons for validation of evaluated nuclear data

Abstract

An experimental system for benchmark validation of nuclear data with slab samples has been set up at China Institute of Atomic Energy (CIAE). Neutron leakage spectra in the range of 0.8–16 MeV from iron slab samples were measured by time-of-flight technique using a D-T neutron source with the measured angle at 60° and 120°. The thicknesses of the slabs were chosen to be 5 cm, 10 cm and 15 cm. The experimental results were compared with the calculated ones by MCNP-4c simulation, using the evaluated data of iron from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 libraries.From the comparison of neutron spectra and the C/Es between the measured and the calculated results, it has been found that some discrepancies in the major reaction channels including (n, p), (n, n′) and (n, 2n) are existing. Detailed information about the neutron product distribution with the evaluated data has been presented to explain the discrepancies which turn out to the data of the above three libraries that needed to be improved as required in different energy ranges.