학술논문
Improved measurement results for the Avogadro constant using a 28Si-enriched crystal
Document Type
Working Paper
Author
Azuma, Y; Barat, P; Bartl, G; Bettin, H; Borys, M; Busch, I; Cibik, L; D'Agostino, G; Fujii, K; Fujimoto, H; Hioki, A; Krumrey, M; Kuetgens, U; Kuramoto, N; Mana, G; Massa, E; Meeß, R; Mizushima, S; Narukawa, T; Nicolaus, A; Pramann, A; Rabb, S A; Rienitz, O; Sasso, C; Stock, M; Vocke Jr, R D; Waseda, A; Wundrack, S; Zakel, S
Source
Metrologia 52 (2015) 360-375
Subject
Language
Abstract
New results are reported from an ongoing international research effort to accurately determine the Avogadro constant by counting the atoms in an isotopically enriched silicon crystal. The surfaces of two 28Si-enriched spheres were decontaminated and reworked in order to produce an outer surface without metal contamination and improved sphericity. New measurements were then made on these two reconditioned spheres using improved methods and apparatuses. When combined with other recently refined parameter measurements, the Avogadro constant derived from these new results has a value of $N_A = 6.022 140 76(12) \times 10^{23}$ mol$^{-1}$. The X-ray crystal density method has thus achieved the target relative standard uncertainty of $2.0 \times 10^{-8}$ necessary for the realization of the definition of the new kilogram.
Comment: postprint, 22 page, 3 figures, 14 tables
Comment: postprint, 22 page, 3 figures, 14 tables