camilla.compton@LIGO.ORG - posted 13:33, Friday 30 September 2022 (65164)
Added irises to FCGS and SQZ path on SQZT7 to check alignment after vent.
Sheila, Georgia, Camilla. WP10723, WP10727.
After we found the co-alignment of IR and green beams had shifted at some point (realigned in alog 65032), we set iris to monitor the FCGS and SQZ beams on SQZT7 after HAM7 is pumped down.
Fil turned on the HAM7/SQZT0 HV (needed for the SHG and OPO PZT), Austin took HAM7 SEI to ISOLATED. We went to local laser hazard.
After locking SHG and REFL. We adjusted the top (FCSG/SK path) periscope mirror to stop the FCGS path from clipping the bottom mirror, as it shifted with the H:M2 co-alignment adjustment (found in alog 65066).
We added an iris on the FCGS path just after the lower periscope mirror and just before the FC camera, photo. Sheila realigned the beam onto the camera by touching MG3 and MG4 (SQZT7 - D2000242). The FCSG beam looked strange. The 1st iris blocks the SK beam, photo.
We added an iris in the SQZ path just after the lower periscope mirror, photo, and used MR18 to center the beam on the camera instead of a second iris. Photo of both cameras here.
Later: we will need to realign the SK path, will do when we swap the top perescope mirror. Also will need to check FCGS is on the PD.
We keyed off the SQZ laser, Fil turned off the HV and Austin took HAM7 SEI back to DAMPED. The laser curtains fell onto the back of one of the chassis but nothing got unplugged or looked hurt, photo here, sorry!
Images attached to this report
