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.
作者
祖铁军
汤勇强
曹良志
吴宏春
ZU Tiejun;TANG Yongqiang;CAO Liangzhi;WU Hongchun(School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
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)。
关键词
氢化锆
第一性原理
热散射律
热散射截面
NECP-Atlas
zirconium hydride
first-principles
thermal scattering law
thermal scattering cross section
NECP-Atlas
