The FSS started to oscillate about 150seconds 30seconds before we lost lock. During relocking we keep losing lock at various places and there is slight motion seen in the Ref Cav Trans spot.
Images attached to this comment
thomas.shaffer@LIGO.ORG - 09:58, Thursday 13 February 2020 (55083)Lockloss, PSL
I have looked into what are normal ranges for this channel are when we are locked (over the past month and a snapshot in July, which looked similar).
It seems that we survive periods with the FSS piezo channel H1:PSL-FSS_FAST_MON_OUT_DQ sustained near 3. And survive fast spikes up 9. Seen in the attached images (sustained vs peaks).
The value of this channel on both cases the IFO lost lock that TJ found, were sustained near 6. so much higher than we normally see.
Images attached to this comment
camilla.compton@LIGO.ORG - 13:04, Friday 20 March 2020 (55697)PSL
In the week spoken about above, we had 5 locklosses that looked like this with the FSS_NPRO_TEMP and FSS_FAST (PZT) signals oscillating shortly before lockloss:
The FSS started to oscillate about
150seconds30seconds before we lost lock. During relocking we keep losing lock at various places and there is slight motion seen in the Ref Cav Trans spot.The lock loss at 0714 UTC looks similar as well. Something is seen in that channel 45 seconds before.