23:42:12UTC Pushed out of Observing by SQZ_MANAGER
We got multiple SDF Diffs appearing (attachment1 and 2), but they kept changing so the ones in the attached screenshot were the earliest ones we could get. Attachment3 shows the SQZ_MANAGER log from that time and Attachment4 shows the SQZ_FC log from that time.
Naoki and Vicky were able to relock the squeezer by manually moving the beam spot, but are running some tests before we go back into Observing.
Naoki, Vicky
Re-aligning FC2 P/Y sliders manually was able to bring squeezer back. Steps taken just now, which seemed to work (tagging OpsInfo). Screenshot of some relevent medms.
- Paused SQZ_FC Guardian manually
- sitemap > SQZ > SQZ Overview > FC SERVO (medms)
--> manually locked FC VCO GREEN by engaging (closing) the servo (red switch) on the common mode board. Can also increase common gain slider from e.g. 5 -->15/20 if alignment has trouble holding. (GRD will reset everything, so adjust gains however to hold a lock)
--> could see a weak and flashing TEM00 spot on FC GREEN TRANS camera, so adjusted FC2 P/Y sliders to maximize FC GREEN TRANS spot on the camera. This also maximized FC GREEN transmission flashes, like on H1:SQZ-FC_TRANS_C_LF_OUTPUT. - Trends screenshot shows trends when squeezer dropped. FC2 was aligned, and you can see flashes on the bright green FC transmission PD (H1:SQZ-FC_TRANS_C_LF_OUTPUT) increase. For alignment, you can use green transmission flashes on the PD, or watch the spot on the camera, which got brighter to what you see in the screenshot (note also the location of the beam spot on the camera; this is where the cavity should be).
- Un-paused SQZ-FC guardian. Then from SQZ_MANAGER, re-selected FREQ_DEP_SQZ. The squeezer went back fine after this.
- Accepted FC2 SUS SDF diffs after squeezer was back to FDS.
Will investigate why the alignment had to be manually walked (we haven't done this in 1-2 months; ASC typically takes care of FC alignment fine). Likely similar issue that Corey had last night LHO:72050; if this happens again, we can try aligning FC2 in this way.
00:05:12 Returned to Observing
We found that SQZ ASC has been OFF since 6 days ago (first attached figure). We took SQZ data 6 days ago in alog71902. During this measurement, we turned off SQZ ASC for alignment of anti squeezing. We changed the SQZ ASC flag in sqzparams to False and set back to True after the measurement, but we may forgot to reload the SQZ_MANAGER guardian. We asked Oli to reload the SQZ_MANAGER guardian when lockloss happens. We went to commissioning and manually turned on the SQZ ASC switch and went back to observing in a minute.
We also found that the SQZ ASC switch (H1:SQZ-ASC_WFS_SWITCH) and FC ASC switch (H1:SQZ-FC_ASC_SWITCH) are not monitored. We monitored them as shown in the second, third attached figure.
