| Zugriffsnummer | 24149 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Aperture correction for a sphere interferometer |
| Autor(in); Institution |
Nicolaus, Arnold; 5.4, Interferometrie an Maßverkörperungen, PTB-Braunschweig
Bönsch, Gerhard; PTB-Braunschweig, retired staff
|
| Quelle/Jahr | Metrologia: 46 (2009), 6, 668 - 673 |
| ISSN | 0026-1394 (PRINT) ; 1681-7575 |
| DOI | |
| Verlag | Bristol: IOP |
| Klassifikationscode | PACS: 06.20.Jr ; PACS: 07.60.Ly ; PACS: 61.05.cp |
| Freie Schlagworte | coefficient of thermal expansion ; enriched Si ; silicon sphere ; Avogadro constant ; sphere interferometer ; length measurement ; lattice parameter |
| Zusammenfassung | Considerations have been made to derive a correction for the diameter measurements of a sphere by means of a special sphere interferometer. This correction is caused by the finite diameter of the light source acting as the entrance 'pinhole' aperture in the light collimating system. The finite diameter has the effect that the wave which is incident on the sphere is a superposition of spherical waves which are slightly inclined with respect to each other. The resulting correction is essential for high accuracy dimensional measurements of silicon spheres to determine the Avogadro constant - a new determination of which is a contribution to a new definition of the kilogram. |
