基于确定论的ZrH_(x)中H热中子散射数据评价

Evaluation of Thermal Neutron Scattering Data for H in ZrH_(x) Based on Deterministic Method

ZrH_(x)由于具有较高的H含量和较好的慢化特性,在核技术中得到了广泛的应用,然而,ZrH_(x)中H的热中子散射数据的产生大多采用了直接数值模拟的方法,并未经过基于实验数据的评价。本文提出了一种与半经验声子模型相关的ZrH_(x)中H的热中子散射数据的快速确定论评价方法,通过采用广义最小二乘法将计算机模拟的热散射数据与实验数据进行调整来完成,实验数据采用总截面测量值和反应堆基准题的有效增殖系数(k_(eff)),结果表明,经过调整后ZrH_(x)中H声子态密度光学项的能量区间发生高能区偏移,所得到的总截面值与实验数据吻合较好,调整之后的2个TRIGA反应堆临界基准题的k_(eff)计算精度得到了改进。

ZrH_(x) has been widely used in nuclear technology because of its high H content and good moderating property.However,the thermal neutron scattering data generation of H in ZrH_(x) mostly uses direct numerical simulation method,which has not been evaluated with experimental data.In this paper,a fast determinstic evaluation method of thermal neutron scattering data of H in ZrH_(x) is presented,which is related to semi-empirical phonon model.It is completed by adjusting the thermal scattering data simulated by computer with the experimental data by using generalized least square method.The experimental data are based on the total cross-section measurements and the effective multiplication coefficient(k_(eff)) of the benchmark reactor.The results show that the optical range of the H phonon density in the modified ZrH_(x) is shifted to high energy region,and the total cross-section values are in good agreement with the experimental data.The accuracy of k_(eff) calculation for the two TRIGA reactors after adjustment has been improved.