We have been unable to relock due to what seems to be the same issue as on June 14 (Georgia's alog49932). ALS COMM cant seem to turn up the gain on the analog LSC refl servo without lock loss. Sheila noticed that the COMM beatnote was low so we opted to try to move PR3. This allowed up to make it past the ALS COMM point, but now the OMs seem to be railed whenever DRMI manages to lock. Initial alignment has not helped with this.
After an initial alignment, DRMI will lock up fine at first but then OM1 and 2 will begin to saturate and the powers will drop in POP18 POP90. This makes me think that the light getting to the OMs is way off, and that this PR3 alignment isnt going to work. With the history cleared for the OMs, the flashes for DRMI look great and it will sometimes catch for about two seconds, but then immediately drop it.
We brought PR3 back and adjusted the ALS/POP beam steering HAM1 picomotor. I adjusted this in pitch and it brought the COMM beatnote from -11 to -4. I'm now finishing alignment and we'll see what happens.
After picoing and finishing the alignment I was able to lock DRMI quickly, but then lost it at CARM_ON_TR. When I went to relock, ALS_COMM was trying to fine tune IR but it couldn't get the power high enough. I manually took the node to search full range and then it found a good place. It just took its time getting there. The rest of the locking sequence went smoothly.