Looking at the REFL baffle will tell me if our current alignment is sufficient to get the REFL beam from the first surface of PRM into HAM1. When I looked at the beam before, it was slightly clipped on the East side of the aperture of the baffle, so misaligned in yaw. I have no knowledge of the alignment state of PRM at the time I saw this clipping. When I have the beam back and a locked IMC, I'll be able to evaluate the REFL/PRM alignment. FYI - there is currently a yellow viewport cover without stickers on the East HAM2 door - this is not an invitation to remove the viewport cover without a work permit or contacting the Control Room! I will either switch the viewport cover to one that has stickers, or get the proper stickers for this cover, before we open the PSL shutter.
I and Cheryl went to the floor, MC was locked, and PRM was aligned so the IFO REFL is centered on the baffle hole before HAM1.
New "aligned" value for PRM alignment slider is [P,Y]=[-730, 0] urad.
This used to be [-830, -50] in air, the change is quite small considering the fact that we're under vacuum now.
With this data even the most serious skeptic should agree that the IO alignment is OK. We should proceed to center IM4 and MC2 trans QPDs because they're quite off-center now.