Measurement of Leakage Neutron Spectra from a Spherical Pile of Zirconium Irradiated with 14MeV Neutrons and Validation of Its Nuclear Data
Measurement of Leakage Neutron Spectra from a Spherical Pile of Zirconium Irradiated with 14MeV Neutrons and Validation of Its Nuclear Data
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DOI：
10.1080/18811248.2003.9715374
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发表时间：
2001-11
影响因子：
1.2
通讯作者：
C. Ichihara;I. Kimura;S. Hayashi;J. Yamamoto;A. Takahashi
中科院分区：
文献类型：
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作者：
C. Ichihara;I. Kimura;S. Hayashi;J. Yamamoto;A. Takahashi
为了对锆核数据进行基准验证，利用14 MeV中子源设施OKTAVIAN的飞行时间技术测量了直径61厘米的锆球的泄漏中子谱，测量范围为0.1至16 MeV。将计算结果与蒙特卡罗程序MCNP-4A的计算结果进行了比较。为了研究单个中子反应的谱依赖关系，用基于JENDL-3.2的库，用MCNP-4A程序进行了测试计算，其中部分截面值从原始值减去。通过对测量光谱和计算光谱的比较，发现两种结果基本上都能很好地预测实验。然而，详细地说，ENDF/B-VI和EFF-2.4在1 MeV以上都高估了很多。JENDL-3.2除了低于0.8 MeV和10 MeV左右外，对光谱的预测几乎令人满意。JENDL-3.2计算中发现的差异是由于(n，2n)反应的截面值及其二次能量分布(SED)所致。修改后的JENDL-3.2库的(n，2n)反应值降低，SED低于1 MeV，在整个能量范围内与实验结果吻合较好。
In order to make a benchmark validation of the nuclear data for Zr, the leakage neutron spectrum from a Zr sphere of a 61-cm diameter was measured between 0.1 and 16MeV using a time-of-flight technique with a 14MeV neutron source facility, OKTAVIAN. The result was compared with the calculation using the Monte Carlo code MCNP-4A. To investigate the spectrum dependence on the individual neutron reactions, test calculations were carried out with the MCNP-4A code using the JENDL-3.2-based libraries, in which partial cross section values were reduced from the original values. From the comparison between the measured and the calculated spectra, it was found that each of the results could predict well the experiment in general. However, in detail, both ENDF/B-VI and EFF-2.4 gave considerable overestimation above 1 MeV. The JENDL-3.2 predicts the spectrum almost satisfactorily except below 0.8 MeV and around 10 MeV. The discrepancy found in JENDL-3.2 calculation is considered due to the cross section values of the (n, 2n) reaction and its secondary energy distributions (SED). The modified JENDL-3.2 library with the reduced (n, 2n) reaction values and the lower SED below 1 MeV reproduced the experiment with better agreement over the whole energy range.