Volume measurements of 28Si-enriched spheres using an improved optical interferometer for the determination of the Avogadro constant
Volume measurements of 28Si-enriched spheres using an improved optical interferometer for the determination of the Avogadro constant
复制标题
使用改进的光学干涉仪测量富含 28Si 的球体的体积，以确定阿伏加德罗常数
DOI：
10.1088/1681-7575/aa5379
复制
发表时间：
2017
期刊：
影响因子：
2.4
通讯作者：
Hajime Inaba and Kenichi Fujii
中科院分区：
文献类型：
--
作者：
Naoki Kuramoto;Yasushi Azuma;Hajime Inaba and Kenichi Fujii
为了通过X射线晶体密度法测定阿伏伽德罗常数，1公斤硅球的准确体积测量是至关重要的。为此，改进了光学干涉仪，并用于测量两个1 kg硅球的体积，所述硅球由高度富集28 Si的硅晶体制成。球体的表观体积不考虑表面层对干涉测量体积的影响，其相对标准不确定度为2.0× 10− 8。用改进的椭圆偏振光谱仪对微球表面进行了表征。通过考虑表面层的影响，球的核心体积，其中不包括表面层，被确定。2015年，这些结果被用于确定阿伏伽德罗常数，作为国际阿伏伽德罗协调项目组织的框架。本文详细介绍了测量方法、仪器改进、数据分析和不确定度评定。
For the determination of the Avogadro constant by the x-ray crystal density method, an accurate volume measurement of 1 kg Si spheres is of primary importance. For this purpose, an optical interferometer was improved and used to measure the volumes of two 1 kg silicon spheres which were manufactured from a silicon crystal highly enriched in 28 Si. The apparent volumes of the spheres, which do not take into account the influence of the surface layers on the volume measurement by interferometry, were determined with a relative standard uncertainty of as small as 2.0× 10− 8. The surface of the spheres was characterized by using an improved spectroscopic ellipsometer. By considering the influence of the surface layers, the core volumes of the spheres, which exclude the surface layers, were determined. These results were used for the determination of the Avogadro constant in 2015 as a framework organized by the International Avogadro Coordination project. This paper provides details on the measurements, the improvements made to the apparatus, the data analysis and the uncertainty evaluation.