1.1. Background This article reports work carried out under the auspices of the Committee
on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. 1 It …

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 …

When the kilogram is redefined in terms of the fixed numerical value of the Planck constant
h, the x-ray-crystal-density (XRCD) method, among others, is used for realizing the redefined …

This paper concerns an international research project aimed at determining the Avogadro
constant by counting the atoms in an isotopically enriched silicon crystal. The counting …

The Planck constant h is one of the most significant constants in quantum physics. Recently,
the precision measurement of the value of h has been a hot issue due to its important role for …

Abstract The spacing of the {2 2 0} lattice planes of a 28 Si crystal, used to determine the
Avogadro constant by counting silicon atoms, was measured by combined x-ray and optical …

13. Relative directions of the reciprocal vector h of the diffracting planes, unit normal to the
analyser n (front mirror, with reference to the obverse layout of the analyser), and …

Precision X-ray methods for absolute and relative determination of crystal lattice parameters
(interplanar distances) are described and compared, including the X-ray divergent-beam …

Surface layer characterization is crucial for the high-accuracy determination of the Avogadro
constant using 28 Si enriched spheres to redefine the kilogram. In this paper, we measured …

X-ray interferometry established a link between atomic and macroscopic realisations of the
metre. The possibility of measuring the silicon lattice parameter in terms of optical …