中子衍射应力谱仪垂直聚焦单色器的优化设计  

Optimal simulation of vertical monochromator of neutron diffraction residual stress instrument

作　　者：王晓影[1] 李建[1] 谢超美[1] 刘荣[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《光学精密工程》2008年第10期1880-1885,共6页Optics and Precision Engineering

基　　金：中国工程物理研究院科学技术基金课题资助项目(No.20060210)

摘　　要：为提高应力谱仪样品处的中子注量率,对垂直聚焦单色器进行了优化设计。应用蒙特卡罗模拟程序MCSTAS对中子衍射应力谱仪的垂直聚焦Ge(511)单色器进行优化计算,得到了垂直聚焦单色器的高度与单晶片之间的倾角等参数的最佳值。然后,对比分析了在垂直聚焦单色器与平板单色器两种情况下样品处的中子注量率。最后,讨论了单色器起飞角对谱仪分辨率的影响。计算结果表明:单色器尺寸为50 mm×150 mm;垂直单色器在样品台中心位置的中子注入量是平板单色器的4.99倍,表明利用垂直单色器可以显著提高应力谱仪样品处的中子注量率。In order to increase the neutron flux at the sample position in a residual stress instrument, the optimal design of vertical monochromator was researched. An optimization simulation was performed for the vertical focusing monochromator Ge （511） of neutron diffraction residual stress instrument, and several optimized parameters, such as the height of the monochromator and the angle between two adjacent crystals were obtained. Then, the neutron fluxes at the sample positions in vertical and flat monochromators were analyzed contrastively. Finally, the influence of the take-off angle of monochromator on instrument resolution was discussed. The calculation results indicate that optimized monochromator dimension is 50 mm× 150 mm, and the neutron flux of the vertical monoehromator is 4.99 times as many as that of flat one. These results show that proposed vertical monochromator can improve the neutron flux considerably at sample position in residual stress instrument.

关 键 词：中子衍射 应力谱仪 单色器 垂直聚焦 中子注量率 

分 类 号：TL817.3[核科学技术—核技术及应用]