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内容記述 |
To assess the accuracy of iron data in the latest nuclear data libraries, mainly FENDL-3.2b, for accelerator-based fusion neutron source designs, we analyzed the QST/TIARA iron experiment with quasi mono-energy neutrons of 40 and 65 MeV, and the JAEA/FNS iron experiment with DT neutrons, by using the Monte Carlo code MCNP6.2. As the results, we found the following issues: 1) the calculation result with FENDL-3.2b underestimated the measured neutron flux in the continuous energy range (10 - 60 MeV) by 40 % in the TIARA experiment with 65 MeV neutrons, 2) it tended to underestimate the measured neutron flux above 10 MeV by 20 % at a depth of 70 cm and overestimate that below 10 keV by 30 % up to a depth of 40 cm in the FNS experiment. We modified the FENDL-3.2b iron data to investigate these issues and identified underlying remarks: 1) the non-elastic and in- elastic scattering data of 56Fe in FENDL-3.2b underestimated the measured neutron flux above 10 MeV, 2) the (n, np) data of 56Fe in FENDL-3.2b overestimated the measured neutron flux above 10 MeV, and 3) the inelastic scattering and (n,2n) data of 56Fe and the inelastic scattering data of 57Fe in FENDL-3.2b caused the over- estimation of the measured neutron flux below 10 keV. These issues of 56,57Fe in FENDL-3.2b should be improved. |
