CENDL库中Fe、W评价数据的改进对屏蔽积分实验计算结果的影响

利用中国原子能科学研究院核数据重点实验室中子积分实验装置，分别完成了氘氚中子与不同尺寸Fe、W样品作用的泄漏中子飞行时间谱实验测量。利用MCNP 4C程序开展了泄漏中子飞行时间谱的模拟计算，Fe和W的评价数据分别采用CENDL 32库及CENDL 31库的数据，并将两数据库模拟结果与实验结果进行对比分析，重点分析了CENDL 32库中Fe和W的数据的改进与不足。结果表明：对Fe中子评价数据，CENDL 32库在弹性散射能区、连续能级非弹性散射能区及分立能级非弹性散射能区，模拟结果均与实验结果符合较好，较CENDL 31库有明显改善；对W中子评价数据，CENDL 32库在非弹性散射能区的模拟结果与实验结果符合较好，较CENDL 31库有明显改善，但在弹性散射能区模拟结果高于实验结果，在(n,2n)反应能区模拟结果低于实验结果。CENDL 32库关于天然W的中子评价数据有待进一步改善。

Influence of Improvement of Fe and W Evaluated Nuclear Data of CENDL Library on Calculated Result of Shielded Integral Experiment

Based on the neutronics integral experimental facility at China Institute of Atomic Energy, the neutron leakage spectra from iron samples and tungsten samples of different sizes were measured by time of flight technique using D T neutron source. The leakage neutron spectra were simulated by Monte Carlo transport code MCNP 4C, using the data from the CENDL 32 and CENDL 31 evaluated nuclear data libraries. By comparing the theoretical results with the experimental results, the improvement and deficiency of Fe and W data from the CENDL 32 library were analyzed. According to the comparison results, some results were got. As for the evaluation nuclear data of Fe, the calculation results of the CENDL 32 library agree well with the measured data in the elastic scattering energy region, the continuous inelastic scattering region and the discrete inelastic scattering region, which are better than the calculation results of the CENDL 31 library. As for the evaluation nuclear data of W, the calculation results of the CENDL 32 library agree well with the measured data in the inelastic scattering region, which are better than the calculation results of the CENDL 31 library. However, the calculation results of the CENDL 32 library are higher than the measured results in the elastic scattering energy region. Besides, the calculation results of the CENDL 32 library are lower than the measured results in the (n, 2n) reaction. The CENDL 32 evaluated nuclear data of W nucleus should be further improved.