Naoki, Sheila, Camilla. WP 11979

Using the SQZ (ZM4/5/6) and SRM alignment of our last time in NLN, Naoki added two irises in the IR path of SQT7 so that we can keep store this alignment if we vent. This is the path of the SQZ beam heading to the IFO, reflected off beam divertor, to serve as a reference for the alignment which doesn't have good throughput in HAM5.

• First iris after periscope: location and photo.
• Second iris before trans/HD flipper mirror: location and photo.
• Beam on SQZT7 IR Trans camera: photo.

As noted in alog79128 the beam on AS_C isn’t centered in this alignment, it’s around 0.1-0.3 off center. We moved ZM4 to align to the center of AS_C (noisy as NSUM was 0.15mW), we didn't see a noticeable difference on the irises.