Craig, Terra, Dan
Here's some observations from today on issues with locking, overall the alignment doesn't seem great and I'm not sure what we're doing wrong:
We ran initial alignment several times today. However, during MICH dark align the WFS seem to be taking us to something other than the symmetric elephant shape we usually have. We checked the phasing of AS45_B today and it all seemed fine. We touched up BS in either PRMI or check mich fringes if it wouldn't even lock that. Seems suspicious.
DRMI has been taking a long time to lock, PRMI seems fine, flashes look good.
Doing initial alignment of the arms has also been troublesome, getting good flashes in green has been more difficult than before, Y-arm has been particularly temperamental.
Getting through ENGAGE_REFL_POP_WFS was bit of a rollercoaster each time, PRC1 and PRC2 made some large detours.
We managed to get up to nominal low noise once for a few hour lock. The final lock didn't look very good though, there was a steady 0.6Hz oscillation in the PRG/RF18/arm powers that wouldn't die down, although it was stable overzealous commissioning brought it down.
We're trying to get it locked so Terra can do some PI work, however it's not looking likely at the moment.
I upped the upper thresholds on MICH and SRCL DRMI locking from 37 to 60, since our trigger POPAIR B RF18 I is around 140 cts when locked. This seemed to moderately help with the last two DRMI locks (2 mins, 8 mins).
The increased contrast defect from the TCS pre-loading might have changed the offset on the MICH DARK wfs loop, so Mich alignment probably should be adjusted by hand until it's fixed.
We also have MICH_BRIGHT_ALIGN, which uses a dither alignment.