[ericq, lydia, steve, gautam]

• We aligned the arms, and centered the in-air AS beam onto the PDs and camera
• Misaligned the ITMs in a controlled ramp, observed ASDC level, didn't see any strange features
• We can misalign the ITMs by +/- 100urad in yaw and not see any change in the ASDC level (i.e. no clipping). We think this is reasonable and it is unlikely that we will have to deal with such large misalignments. We also scanned a much larger range of ITM misalignments (approximately +/-1mrad), and saw no strange features in the ASDC levels as was noted in this elog - we used both the signal from the AS110 PD which had better SNR and also the AS55 PD. We take this to be a good sign, and will conduct further diagnostics once we are back at high power.
• Opened up all light doors, checked centering on all 6 OM mirrors again, these were deemed to be satisfactory 
• To solve the green scattering issue, we installed a 1in wide glass piece (~7inches tall) mounted on the edge of the OMC table to catch the reflection off the window (see Attachment #1) - this catches most of the ghost beams on the PSL table, there is one that remains directly above the beam which originates at the periscope in the BS/PRM chamber (see Attachment #2) but we decided to deal with this ghost on the PSL table rather than fiddle around in the vacuum and possibly make something else worse
  Link to IMG_2332.JPG
  Link to IMG_2364.JPG
• Re-aligned arms, ran the dither, and then aligned the PRM and SRM - we saw nice round DRMI flashes on the cameras
• Took lots of pictures in the chamber, put heavy doors back on. Test mass Oplev spots looked reasonably well centered, I re-centerd PRM and SRM spots in their aligned states, and then misaligned both
• The window from the OMC chamber to the AS table looked clean enough to not warrant a cleaning..
• PSL shutter is closed for now. I will check beam alignment, center Oplevs, and realign the green in the evening. Plan is to pump down first thing tomorrow morning

AS beam on OM1

Link to IMG_2337.JPG

AS beam on OM2

I didn't manage to get a picture of the beam on OM5 because it is difficult to hold a card in front of it and simultaneously take a photo, but I did verify the centering...

It remains to update the CAD diagram to reflect the new AS beam path - there are also a number of optics/other in-vacuum pieces I noticed in the BS/PRM and OMC chambers which are not in the drawings, but I should have enough photos handy to fix this.  

Here is the link to the Picasa album with a bunch of photos from the OMC, BS/PRM and ITMY chambers prior to putting the heavy doors back on...

SRM satellite box has been removed for diagnostics by Rana. I centered the SRM Oplev prior to removing this, and I also turned off the watchdog and set the OSEM bias voltages to 0 before pulling the box out (the PIT and YAW bias values in the save files were accurate). Other Oplevs were centered after dither-aligning the arms (see Attachment #8, ignore SRM). Green was aligned to the arms in order to maximize green transmission (GTRX ~0.45, GTRY ~0.5, but transmission isn't centered on cameras).

I don't think I have missed out on any further checks, so unless anyone thinks otherwise, I think we are ready for Steve to start the pumpdown tomorrow morning.