[Jenne, JeffK, Patrick, Kara, Niko, JeffB]

As Jeff noted in his earlier alog 50952, I think that the Yarm alignment that was arrived at yesterday was such that the IR beam came into resonance with the beam spot on the other side of the ITMY point absorber than we usually sit at.  When all the ADS loops were closed except for PIT3 (which moves PRM to set the spot position on ITMY in pitch) and we couldn't move the PRM to get the ADS error signal close to zero without causing DHARD and other ASC loops to oscillate, I thought I'd try moving the ITMY P2L gain to get a rough idea of what value would zero the PIT3 ADS line.  It turned out that a value of +2 (which corresponds to a spot position of -5.2mm in pitch) was pretty good.  This is quite different from our old nominal ITMY P2L value of -3.0 (which corresponds to a spot position of +17.4mm in pitch). 

While at 2W I moved all of the A2L values of the test masses to move the spots and try to improve the buildups.  Recall that ITMX isn't used in-loop, but needs to be adjusted to reduce angular noise in DARM that drowns out the other A2L lines.  I was able to get a power recycling gain of 48 with a POP18 value in the high 60s, which is much better than we usually do at 2W.  I reset the green initial alignment setpoints to match these spot positions.  When we increased power to 20W, buildups still looked good, so we went ahead and increased further to the full 37W input power but this caused all of our buildups to drop quickly.  Also, the OMC ASC was saturating the OMC suspension(true with the usual QPDs and when I tried to switch over to the dither.  Haven't tried deacon.).  I had the OMC ASC loops open, and I had just started moving the spots around a bit, and we lost lock.  To prevent this, next lock I will try to move spots a bit while we are still at 20W, where the OMC SUS didn't saturate.

Upon trying to reacquire, Patrick noted that the ALS COMM beatnote was lower than normal, around -14dBm (we've been running at about -10dBm, but it really ought to be higher than that.).  We do not usually move PR3, but since the alignment of the IFO changed drastically today Patrick paused the INIT_ALIGN guardian when it was working on the green alignment and moved PR3 to get the COMM beatnote up to -3dBm.  This caused the Xarm IR portion of initial aligment to not catch lock, so I hand-moved PR2 and IM4 to compensate for the PR3 pitch move and then let the ASC take over once the Xarm caught lock. 

Earlier today we were losing lock at CARM_TO_TR because there wasn't enough light on the Yarm QPD_B.  I temporarily had put in CARM_TO_TR to move the carm offset closer to zero than normal, which allowed enough light to hit the Y QPD_B that we could make the transition.  But, after Patrick's recent initial alignment, that was moving us too close to zero so I have once again removed it and the carm offset reduction sequence is back to its normal settings.

Next lock we went to DC readout, and saw that again the POP18 and PR gain buildups were good.  We then went to 20W where I tried for a while to improve the buildups, but was not cery successful.  I did a bit, but not back to our 2W place.  And, these moves put us much closer to the locations that we had been on our test masses.  Kind of disappointing.  I went to 37W and tried a bit more spot moving, but no real changes there.  With these new spots and a small extra OMC QPD offset I was able to leave the OMC ASC engaged on the QPDs without saturating the suspension.  At this point, I am beat.  The IFO is at NomLowNoise, kind of okay range, so we can come back and address remaining issues tomorrow.

Some SDF snapshots:

• OMC - I have one extra QPD offset that seems to help keep the OMC sus from saturating.  However, with the new A2L values, this may be unneccesary.  We should try removing it tomorrow to see if it helps get some optical gain back.
• ALS X and Y - initial alignment references, still set to the place where I have good 2W buildups.  Won't match current A2L values.
• ISC X and Y - I removed the unused offsets in the TR QPDs.  They were important in O2 and before, when we were still using them at DC for the SOFT loops.  Now they just make the screen more confusing.
• Test mass suspensions - the current A2L values.  Most are pretty similar to what they had been before the camera bump situation.
• TMSX no longer needs an offset when we start increasing the power.  See note below, and Jeff's alog 50952.

A few more notes and words on Kara and my work earlier today on moving the TMSX (mentioned in JeffK's alog 50952):  When the IFO was pretty well aligned (Jeff and Niko had moved the arms in soft to get the ADS error signals except PIT3 small), Kara and I noted that both the IR and green QPDs on the TMS were quite far off center in pitch.  So, we pitched the TMS slowly to get the IR QPDs a little better centered, and in parallel moved the green QPD offsets to keep the ALS WFS error signals small.  At some point when we were pretty close, we started running the Kiwamu script that changes the green QPD offsets automatically.  It happens that when the IFO was pretty well aligned, the IR QPDs on TMSY were reasonably well centered, so we left TMSY alone and just reset the Y green QPD offsets.  Thankfully the offsets were happy to go closer to the center of the QPDs, so we avoided having to do any picoing today.

After moving TMSX to recenter the IR QPDs, I have commented out the step in increase_power that put an offset into TMSX pitch alignment.

JeffB has just put us into Observing for the night.  We can work to finish fine tuning the IFO tomorrow.  For tonight, commissioners out.