English

Improved measurement results for the Avogadro constant using a 28Si-enriched crystal

Instrumentation and Detectors 2016-01-25 v1

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 NA=6.02214076(12)×1023N_A = 6.022 140 76(12) \times 10^{23} mol1^{-1}. The X-ray crystal density method has thus achieved the target relative standard uncertainty of 2.0×1082.0 \times 10^{-8} necessary for the realization of the definition of the new kilogram.

Keywords

Cite

@article{arxiv.1512.05642,
  title  = {Improved measurement results for the Avogadro constant using a 28Si-enriched crystal},
  author = {Y Azuma and P Barat and G Bartl and H Bettin and M Borys and I Busch and L Cibik and G D'Agostino and K Fujii and H Fujimoto and A Hioki and M Krumrey and U Kuetgens and N Kuramoto and G Mana and E Massa and R Meeß and S Mizushima and T Narukawa and A Nicolaus and A Pramann and S A Rabb and O Rienitz and C Sasso and M Stock and R D Vocke and A Waseda and S Wundrack and S Zakel},
  journal= {arXiv preprint arXiv:1512.05642},
  year   = {2016}
}

Comments

postprint, 22 page, 3 figures, 14 tables