Having eliminated alignment issues in vacuum, having driven the PZT, and searched with MC1 and MC3, the remaining alignment issue was the bottom periscope mirror in the PSL.  The PZT and optics were restored to the Wednesday night values, when flashing was good, and the beam was on the IOT2L table on the REFL path, and I entered the PSL and adjusted the bottom periscope mirror while Jenne watched MC2 Trans, and the camera on HAM2 West door that I'd repositioned to view the last baffle of the second IMC in-vacuum REFL periscopes, which showed the beam position and when the beam was clipped or not clipped on the baffle aperture.

I aligned to the known good IMC using the bottom periscope mirror, and used both pitch and yaw.  Pitch needed more adjusting, yaw less.  Had pitch been the only alignment change that needed to be recovered, yaw shouldn't have needed any changes, however, in Peter's alog from Saturday (40024), he mentioned a possible alignment change from over the holidays, and on Thursday there was  a temperature excursion in the PSL, which may have combined to shift the beam from it's position from Wednesday night, which may explain why both pitch and yaw on the lower periscope mirror needed to be adjusted to optimize the alignment into the IMC.

After adjusting MC3/MC1 to get good flashing, we checked the power of the REFL beam on IOT2L, and that was 65mW, and when I measured in the PSL, the power incident on the bottom periscope mirror was 71mW, and the reflected power was 65mW (harder to read as the beam heads to the top periscope mirror).

After leaving the LVEA, I worked on the alignment using the PZT and MC1/MC3, and decided to put them all back, and I put the optics back first, and this increased the flashing as seen on MC2 Trans, and then shortly after that the HPO tripped, as I alogged here (40022).

The alignment at the end of Friday was flashing and the beam was on IOT2L, but since I'd moved the HAM2 West door camera, the beam from MC2 was not centered on the HA1 baffle (after IM1), so once the camera is restored to looking at HA1, the MC2 alignment can be evaluated.

Centering the IMC input beam on MC2 Trans and centering the beam from MC2 on HA1 baffle will restore as close as possible the beam path from the in-air IMC alignment.  This is important because this also restores as close as possible the in-air beam position and angle through the IMs, and restores the well centered beam through the IO Faraday, which is a condition we want to have under vacuum. 

I have two more cameras to place on HAM2, to look at the alignment through the IO Faraday.  The camera for the HAM2 East door is in it's camera housing and sitting on the floor between the HEPI peers.