LIGO Document E1900381-v1

FTIR - ETM09 First Contact Residue on S1 HR Surface.

Document #:
Document type:
E - Engineering documents
Other Versions:
This document captures the Sample Record and other documentation of residue observed on the S1 surface of ETM09. After applying a poured layer of First Contact to the surface on 15 Nov 2019, then peeling the layer on 03 Dec 2019, a residue remained visible by eye under "grazing incidence illumination by flashlight".

The outer edge of this residue corresponded to the just-peeled layer that had been applied on 15 Nov 2019; the inner edge of the residue and some other features corresponded to the voids previously left in first contact application for alignment, a technique which has been used with this optic but which is no longer in use.

The sampling for this single FTIR sample consisted of 3x passes over an area on the left-hand side of the S1 surface of ETM09 measuring about 6" x 3" (18 in^2). GariLynn and Stephen were present in the Downs B119 cleanroom at Caltech.

Notes and Changes:
v1 includes sample record (main document)
other files will include video taken of flashlight scanned across surface to show residue.
Related Documents:

DCC Version 3.4.3, contact Document Database Administrators