Kiwamu, Matt, Arnaud, Travis, Betsy

Today, we attempted to look at the alignment of the ITMy to the SR optics.  We immediately could find no beam at all at SR3 (not even from ITMx which had just been aligned yesterday).  So we moved back through HAM3 and 2 and discovered the bypass beam needed realignment again.  Recall that yesterday, the crew also found this path to need realignment.  Today however, we made the assumption that the ground loop hunt at MC3 possibly bumped the bypass mirrors which are inches from the cables being worked on.  After attempting to walk the 2 bypass mirrors a long ways to restore pointing on both the IM TRANS PD on the very SE corner of the table and the MC wall mark (off by ~10mm), we decided something worse must be wrong.  (Hitting both of these marks should assure that the bypass beam is lined up on top of the MC flashing path.)  We paused to check the MC flashing (lowered the PSL power back to 200mW) and then used the flashing beam lever arm between IM1 and 2 to co-align the beams.  We again used the bypass mirrors and tweeked up this alignment.  However, the beam was still off of the IM PD by ~1 cm low in pitch, and the beam was ~2 inches low going into the PR2 baffle.  At this point we decided to do more forensics in the control room.  What we can confirm:

1) The MC flashes with the MC1-3 biases set many many days ago.  This means
- The pointing from the PSL is good.
- The plane of HAM2 and HAM3 have not changed.

2) HEPI checks of level of HAM2 confirm the above.  (Although Hugh mentioned seeing a minor ~3uR rotation of the table.)

3) Sensor spectra checks of the HAUX IM1, IM2, IM3, and IM4 show healthy suspensions wrt. previous reference plots.

4) IM1 and IM2 pointing look healthy as the beam seems ~centered going in and out of the FI.

5) Biases of all 4 IMs had not been changed since the "good" alignment from yesterday.

6) Trends of IM sensors show the jostling of the ground loop hunt on HAM2 at 2pm, but no overall changes to their signal baseline.

7) IM4 ran out of range in pitch to correct the still low beam on the IM PD and PR2.

8) The misalignment happened sometime after we went laser safe at 1:20pm on Monday and today at ~11am when we unshuttered the PSL beam which was still at 1W from Monday - the IM PD never showed signal from the 1W after opening the shutter today.

Tomorrow we plan to start again, doing a more careful alignment of the bypass beam with the MC flashing beam since it was obviously difficult over the short 1m lever arm in-chamber with an IR card.  We will then attempt to realign to HAM4 using IM3 and IM4 if still needed.