Yesterday by the end of the day the main path through to the pericope had been aligned on the X-arm table. This morning we started with a projection as described in https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=13975. As part of this we realigned the beam through the mask to optimize the shape on the screen.
Later today we aligned the power meter, and ISS photodiodes. The QPDs were checked and are stlil aligned. We calibrated the photodiodes and then started to calibrate the rotation stage for the output power to the CP. However we found a maximum throughput of only 2.5W. Clearly we are losing a lot of power somewhere.
The table has a second IR camera located on the optical table. Before the adjustment during the projection the beam on this looked quite uniform. After finding that we were losing power I looked at the image on this camera, which is taken using a 50% splitter mirror from the beam going to the CP. The image is attached, but appears to show that we are now not well aligned through the mask. We'll need to redo this alignment, but it is surprising that the image from the projection and the image on the table look so different. Possibly this is just the lower resolution of the camera used to image the projected beam.
Alastair Heptonstall, Greg Grabeel The projection turned out to be bad as well. Clipping had started from fairly far upstream and the only thing that had changed was the manual rotation stage being removed. The beam was steered back into alignment, but another issue came up. The beam was hitting low on the mask so the flipper mount was removed and replaced with a non-mobile but correct height mount until the flipper mount can be made to the right height.Here we can see just how bad the clipping was. 
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