摘要
In 2018 the main research activities of Nuclear Data Research Group were focused on nuclear data measurements,calculations and fundamental research in heavy ion reactions.Some important results have been obtained.In order to validate nuclear data and the neutron transportation performance of the materials related to the accelerator driven subcritical system(ADS),we measured the leakage neutron spectra from multiple-slab sample assemblies using 14.8 MeV D-T neutrons[1].The measurement was performed at China Institute of Atomic Energy using time-of-flight method.Two types of assemblies comprising A-1(W+U+C+CH2)and A-2(U+C+CH2)were both built up gradually starting with the first wall.The measured spectra were compared with the MCNP simulations with ENDF/B-VII.1,JENDL-4.0 and CENDL-3.1 libraries.The results show that the experimental leakage neutron spectra for both A-1 or A-2 were reproduced well by the three evaluated nuclear data libraries with discrepancies of less than 15%(A-1)and 12%(A-2),2),except when below 3 MeV.For 2cm and 5cm uranium samples,the CENDL-3.1 calculations exhibited large discrepancies in the energy range of 28MeV and above 13MeV.
