alexan.staley@LIGO.ORG - posted 17:11, Thursday 14 November 2013 (8558)
EX findings (cables, PDs, and polarization)
(Alexa, Stefan)
This morning we had noticed a swap in QPD A and B between in-vac and the medm screens/front end. This was due to swapped cables from the isc whitening chassis to the AA chassis (in particular cable 11, 12). The cables are now properly connected.
When we shined a flashlight onto the DCPDs on ISCTEX, the readouts were all mixed up. First, we noticed that the cables inside the table to the feedthrough were swapped between the Laser-IR and the Fiber Trans. We also noticed that fiber trans and rejected where swapped between channels in the system manager. This has all been corrected for. The DCPDs now follow the specifications of T1100472-v11 from feedthrough through to the software (ie: Laser-IR: 1, Fiber Rejected: 2, Fiber Trans, 3, Spare: 4).
The BBPDs on the table were checked and are OK
We measured the 532nm polarization to be s-pol at the bottom of the persiscope.