Vicky, Begum, Camilla: Vicky and Begum noted that the CLF ISS and SQZ laser is glitchy.
Vicky's plot shows CLF ISS glitches started with O4b, attached.
Timeline below shows SQZ laser glitches started May 20th and aren't related to TTFSS swaps. DetChar - Request : Do you see these gltiches in DARM since May 20th?
- Pre-April 25: no glitches
- 25 April: TTFSS issues, Removed Chassis S2300258, Installed Chassis S2300259 (alog 77418); also caused SQZ rack glitch: 77424 / FRS 31061
- 25 April - 7 May: no glitches apart from on Tuesday April 30th
- 7 May: Reinstalled repaired TTFSS. Removed Chassis S2300259, Installed Chassis S2300258 (77688)
- 7 May - May 20th: Glitches stay small
- May 20th 22:00UTC (Monday): First glitch shown on detchar summary page /20240520/sqz/glitches/
- Day shift summary: 77941 included PR2 spot move, but don't expect glitches could be IFO alignment dependent.
- Lots of glitches since May 20th. These glitches aren't constant and seem to get better and worse on different days, in general got worse since May 20th.
Summary pages screenshots from: before glitches started, first glitch May 20th (see top left plot 22:00UTC), bad glitches since then.
Missed point:
- 9 May: TTFSS issues, Removed Chassis S2300258, Installed Chassis S2300259, 77734 later saw the issues were from fiber polarization not the chassis.
In addition to previous report, I must note that glitches started on May 9th and continued for several times even before to May 25th.
Glitches are usually accompanied by the increased noise in H1:SQZ-FIBR_EOMRMS_OUT_DQ and H1:SQZ-FIBR_MIXER_OUT_DQ channels.
Andrei, Camilla
Camilla swapped the TTFSS fiber box 78641 on June 25th in hopes that this will resolve the glitches issue.
However, it made no difference: Figure (see from 20:40 UTC, as it is when TTFSS box was swapped).
