期刊
MEASUREMENT SCIENCE AND TECHNOLOGY
卷 20, 期 9, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/0957-0233/20/9/092002
关键词
Avogadro constant determination; kilogram redefinition; fundamental physical constants; enriched silicon-28; mass measurements; density measurements; molar mass measurements; lattice parameter measurements; volume measurements; crystal characterization; x-ray; interferometry; optical interferometry
This review describes the efforts of several national metrology institutes to replace the present definition of the kilogram by a new one based on the mass of a given number of 12C atoms. This requires the determination of the Avogadro constant with a relative uncertainty no greater than 2 x 10(-8). Since in previous attempts the most significant limiting factor has been the measurement of the average molar mass of the natural silicon, an international collaboration has been set up to produce a 5 kg single crystal with an isotope enrichment over 99.985%. The technological steps enabling the production of this high-purity Si-28 crystal are also reported.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据