LIGO Document L1200291-v5

TRB Report: Recommendation related to the discrepancy between single version of the quad ITM suspensions and the optical layout which calls for a left and right handed versions

Document #:
LIGO-L1200291-v5
Document type:
L - Letters and Memos
Other Versions:
Abstract:
We the TFB recommend to aLIGO management the following: -

For LLO: - Due to the fact that the CP ITMy was already installed (Oct 2012) we will flip CP ITMy in-situ and cut ESD cabling this making the ESD un-available *. That we then leave LLO ITMy as is without ESD available for duration of project. This can occur as it is not known if ESD is needed on the ITM’s.

For LHO and 3rd IFO: -
Due to the fact that the H1 ITMy is not installed and 3rd IFO ITMy is yet to be built we will create another version of the Compensation Plate (CP) with the wedge angle flipped 180 degrees, so that there is a left-handed and a right-handed version, and implement this new CP version in the ITMy quad suspensions for LHO ** and 3rd IFO. Originally there was one version of the CP.

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Notes and Changes:
V5 NOW INCLUDES THE RECOMMENDATION FROM THE TRB FOR MANAGEMENT.

4/23/2014 Dennis Coyne's comments: The aLIGO project may decide to implement the change/correction for the L1 ITMy CP in order to make the ITMy ESD operational. However it does not currently appear to be necessary for completion of the project. This deviation from intended design/implementation shall be noted in the acceptance documentation so that we don't forget the discrepancy. However for the time being no correction for the L1 CPy will be pursued. The TRB's report & recommendation is accepted.

see also Integration Issue & ECR Tracker entry #20:
https://services.ligo-wa.caltech.edu/integrationissues/show_bug.cgi?id=20

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