Title :
Comparison of IMGC and PTB Absolute Determinations of the Si(220) Lattice Spacing
Author :
Becker, P. ; Kuetgens, U. ; Mana, G. ; Massa, E.
Author_Institution :
Phys.-Technische Bundesanstalt, Braunschweig
Abstract :
If we want to base the kilogram definition on the mass of the 28Si atom, the present uncertainty of the Si (220) lattice plane spacing has to be lowered by a factor ten. On the way to achieve this improvement, the comparison between the lattice spacing determinations obtained by combined X-ray and optical interferometry via the Si crystal standards MO*4 and WS5C of the IMGC and the WASO 4.2a one of the PTB is intended to assess the 0.16 part per million shift between the lattice spacing values recently obtained in a joint IMGC-NMIJ measurement and the past values obtained by IMGC and PTB
Keywords :
atomic mass; constants; crystal structure; interferometry; measurement uncertainty; 28Si atom; IMGC; MO*4; PTB; Si; Si (220) lattice plane spacing; WASO 4.2a; WS5C; X-ray; crystal standards; optical interferometry; Atomic measurements; Crystals; Geometry; Laboratories; Lattices; Manufacturing; Measurement standards; Metrology; Optical interferometry; Uncertainty;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2004 Conference on
Conference_Location :
London
Print_ISBN :
0-7803-8494-6
Electronic_ISBN :
0-7803-8494-6
DOI :
10.1109/CPEM.2004.305300
