分类: 物理学 >> 核物理学 提交时间: 2024-01-05
摘要: A benchmark experiment on 238U slab samples was conducted using a deuteriumtritium neutron source at the China Institute of Atomic Energy. The leakage neutron spectra within energy levels of 0.816 MeV at 60 and 120 were measured using the time-of-flight method. The samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3, 6, and 9 cm. The leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of 238U evaluated neutron data from CENDL-3.2, ENDF/B-VIII.0, JENDL-5.0, and JEFF-3.3. Based on the comparison, the deficiencies and improvements in 238U evaluated nuclear data were analyzed. The results showed the following. (1) The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60 and 120. (2) The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120. (3) The calculated results for CENDL-3.2 significantly overestimated the measurements in the 38.5MeV energy interval at 60 and 120. (4) The calculated results with JENDL-5.0 were generally consistent with the measurement results.