Fused silica long term stability: case studies
Authors: Vannoni M., Sordini A., Molesini G.
Autors Affiliation: CNR-Istituto Nazionale di Ottica, Largo E. Fermi 6, Firenze 50125, Italy
Abstract: The time stability of fused silica is investigated, reporting new data on two flats that were purchased in 1981. It is found that their present shape is no more plane, exhibiting instead a concavity that is compatible with a very slow laminar flow under the action of gravity. The data are examined altogether with those of prior observations, confirming the occurrence of a relaxation process whose time constant is estimated in the order of 10 years; during such a time period, viscosity approximately increases by a factor of three. Starting from the experimental data so far collected, the computations accounting for the estimates above are given in detail.
KeyWords: Experimental data; Long term stability; Time constants; Time stability; Time-periods, Laminar flow; Optical testing; Units of measurement; Fused silicaDOI: 10.1117/12.896758Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-01-19References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here