Title :
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
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;
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
DOI :
10.1109/CPEM.2008.4574772
