基于第一性原理的氢化锆热散射律计算分析  

Calculation and Analysis of Thermal Scattering Lawof Zirconium Hydride Based on First-principles Calculation

作　　者：祖铁军[1] 汤勇强 曹良志[1] 吴宏春[1] ZU Tiejun;TANG Yongqiang;CAO Liangzhi;WU Hongchun(School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学核科学与技术学院,陕西西安710049

出　　处：《原子能科学技术》2022年第1期106-112,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12075183,11735011);中央高校基本科研基金(xzd012019027)。

摘　　要：声子态密度是计算热散射律数据的基本参数。氢化锆(ZrH_(x))中含氢量的变化会导致晶体结构的变化,进而影响其声子态密度。国际上一般通过拟合实验数据获得ZrH _(x)中氢的参数化的声子态密度,不能体现氢化锆真实的晶体结构。本文基于δ-ZrH _(1.5)和ε-ZrH _(2),采用第一性原理计算了ZrH _(x)中氢的声子态密度,研究分析不同方法获得的声子态密度对热散射截面的影响,以及对含氢化锆的TRIGA反应堆的反应性的影响。数值结果表明,与ENDF/B-Ⅷ.0和JEFF-3.3评价核数据库中的声子态密度模型相比,用第一性原理计算得到的声子态密度模型能产生更精确的热散射截面,且显著提高TRIGA反应堆反应性计算的精度。Phonon density of states(DOS)is the basic input parameter to calculate the thermal scattering law data.Different concentrations of hydrogen in zirconium hydride(ZrH_(x))lead to various lattice structures,and then affect the phonon DOS.In the world,the parameterized mathematical formula of phonon DOS is usually obtained by fitting the experimental results,which cannot reflect the real lacttice structure of ZrH_(x).In this paper,the first-principles calculation was used to obtain the phonon DOS based on the lattice structures ofδ-ZrH _(1.5) andε-ZrH _(2).The impacts of the phonon DOS obtained by different methods on thermal scattering cross sections,and further the reactivity of several TRIGA reactors containing ZrH x were investigated.The numerical results show that,compared with the phonon DOS used in ENDF/B-Ⅷ.0 and JEFF-3.3 evaluated nuclear data files,more accurate scattering cross sections and the neutronics results of TRIGA reactors can be obtained by the first-principles calculated phonon DOS.

关 键 词：氢化锆 第一性原理 热散射律 热散射截面 NECP-Atlas 

分 类 号：TL32[核科学技术—核技术及应用]