The shift started with Ryan looking into why ALSy was causing grief in the afternoon (it would later clear up on its own), but since the beginning of the EVE shift, DRMI locking has been the issue.

Have went through 2-Initial Alignments, as well as several successful PRMIs and CHECK MICH FRINGES.

DRMI Symptoms:

DRMI would start out the first few seconds with strong flashes seen on the camera and decent flashes on ndscopes, but

Then the behavior would switch to an ugly camera image which would be seen as DRMI looking like it's going to catch, but within 1-sec POP18+90 (and also the camera) would "wobble" back down to zero in a "slow flash". 

(It feels like DRMI has been like this over the weekend as well, but after some of these wobbles to zero after these "slow flashes,"  DRMI would lock.  Not the case tonight---have had zero DRMI locks going on 6+hrs.)

It feels like the alignment is decent, and no environmental issues, but it doesn't seem to trigger or start LSC control when these flashes start (hence their "slow" drop of POP18+90.). 

What's Been Tried:

• Initial Alignments (have gone through 2).
• Manual Alignment:  This was the first suggestion Sheila gave me.  After PRMI completed, took ISC LOCK to DOWN, went to MANUAL Alignment, and then on ALIGN IFO, selected SRC ALIGN OFFLOADED.  Tried this a few times.  Also tried AS CENTERING OFFLOADED followed by SRC ALIGN OFFLOADED.  For all of these ASC was not far off---leading one to think alignment was fine.
• Checked pointing on AS_C photodetector with SR2 (no real change made here) & also used SRM to make highs higher/lows lower (no change here either).
• NEXT Try Improving DRMI triggering:  Increasing gain of H1:LSC-POPAIR_B_RF18_I (&Q) _GAIN from 2 to 4  (see attached screenshot with appropriate screens)
  • Sheila mentioned this helped with a similar issue 3 weeks ago (see alog83182)
  • I went to the POPAIR RF 18 medm and changed the gains for both I & Q gains from 2 to 4 while ISC_LOCK was trying to lock Green Arms.
  • Then opened up the LSC SDF, which had the safe.snap file up (and then did a sort for this substring: H1:LSC-POPAIR_B_RF18_) and then I ACCEPTED this safe.snap with the new gains of 4 for both of these channels.

Now:  We Wait

Just before Sheila and I were going to go with this new gain, a M6.7 EQ rolled through (of course).  Probably have another 30-90 min before the ground calms down, but the hope is we'll have the same luck Elenna, Ibrahim, and Sheila had on March 4th with DRMI locking right up!