Status of the international effort on the x-ray crystal density work and its progress towards a measurement of the Avogadro constant

Author

Fujii, K. ; Waseda, A. ; Kuramoto, N. ; Becker, P. ; Nicolaus, A. ; Krumrey, M. ; Danzebrink, H.-U. ; Busch, I. ; Bettin, H. ; Mana, G. ; Massa, E. ; Valkiers, S. ; Giardini, W. ; Kessler, E. ; Dowries, S. ; Picard, A. ; Riemann, H.

Author_Institution

Nat. Metrol. Inst. of Japan, AIST, Tsukuba

fYear

2008

fDate

8-13 June 2008

Firstpage

300

Lastpage

301

Abstract

The present status of an international attempt of several national metrology institutes to determine the Avogadro constant with a relative standard uncertainty better than 2ldr10^-8 is presented. To this end, a world-wide collaboration has been set up to produce a 5 kg ²⁸Si single crystal with an enrichment factor greater than 99.985%. Technological steps for the growth of the ²⁸Si single crystal, manufacturing of two 1 kg ²⁸Si spheres, and first experimental results are reported.

Keywords

X-ray crystallography; constants; measurement uncertainty; silicon; Avogadro constant measurement; Si; X-ray crystal density; enrichment factor; standard uncertainty; Atomic measurements; Density measurement; Lattices; Measurement standards; Metrology; NIST; Optical interferometry; Optical surface waves; Silicon; Volume measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Precision Electromagnetic Measurements Digest, 2008. CPEM 2008. Conference on

Conference_Location

Broomfield, CO

Print_ISBN

978-1-4244-2399-6

Electronic_ISBN

978-1-4244-2400-9

Type

conf

DOI

10.1109/CPEM.2008.4574772

Filename

4574772