DRAFT - REPORT  IN PROGRESS - will be finalized at the end of the shift
ITF found in LOW_NOISE_3 in SCIENCE mode. 

Figure 1. There are lots of glitches that are related to B1 photodiode saturations. Are these channels related to one of the family of glitches?

ITF found in LOW_NOISE_3 and in Science Mode. It kept the lock for the whole shift.

INJ
The value of the flag mean_PSL_PMC_TRA_DC trend is decreasing (see attached plot #1). Experts informed of the issue.

TCS
At 11:53 UTC the Guardian chiller system was triggered, swapping the WI chiller with the Backup one.
I've contacted the TCS Oncall (Cifaldi) to inform her of the issue, for the moment the WI Chiller is still switched off but the temperatore of the CO2 laser is stable (see attached plot #2).

I did a survey of the glitch populations present in the Virgo strain data, starting from the end of January 3, after the injection problems were resolved: #65902. In Figure 1 I report the glitchgram (GPS time vs. frequency at the peak of the glitch trigger, with colorscale and markersize representing the SNR) of the triggers in the analyzed period.

Besides the usual 25-minute glitches, visible as continuous triggers between 40 and 50 Hz, the other glitch families are:

• Scatterd Light glitches from bad weather and high microseismic noise, visible as low-frequency trigger clusters on Jan 8-11 (as reported by the operators in entries #65945, #65954, and #65964) Jan 13-14 (#65970).
• A family of glitches very loud (SNR > 200) and very fast glitches, with central frequencies in the bucket 60-400 Hz, has appeared since January 8.
• At a higher frequency, a third family of glitches, weaker than the previous one, seems to have appeared starting from January 19 (and possibly after the injection system failure: #66002 and #66004).

I tried to investigate the origin of these glitches by repeating the correlation analysis via UPV+VetoPerf reported by Nicolas' in #65906.

At this link the complete result of VetoPerf, which I summarize:

• V1:SDB1_OMC1_Peltier_cmd_0 and V1:SDB1_B1_f1_i_DCn_0 seem to act as a veto for a fraction of the glitches with SNR ~1000 in the bucket. However, most glitches in this region did not report any useful channels as vetoes, with the channel list used. More detailed investigations are needed, especially if this very loud family of glitches persists.

• The fainter glitch family started yesterday appears similar to, but significantly less severe than, that identified on January 2: #65902. The resulting correlated channels are the same as found by Nicolas in #65906, specifically INJ_* and SIB2_* channels. In the attached gif the glitchgram before and after applying the veto: note that the majority of triggers after January 19 disappear. We will continue to monitor these glitches but they will likely go away once the INJ issues are fully resolved, as happened earlier inJanuary.

The attached plots show the number of channels related to each DAQ stages (FbmFE, FbmMain, FbmAlp and FbmSt ) according the ITF_LOCK state  since the beginning of 2025 .

There is 5 events of missing channels since the beginning of 2025

• 2025-01-03-05h04m-UTC  - ITF_LOCK_index: 1  : ~30s of incomplete data
• 2025-01-10-01h10m-UTC  - ITF_LOCK_index: 109 : ~60s of  incomplete data
• 2025-01-10-04h44m-UTC  - ITF_LOCK_index: 135 : ~23s of incomplete data
• 2025-01-15-04h15m-UTC  - ITF_LOCK_index: 135: ~78s of incomplete data
• 2025-01-15-17h38m-UTC  - ITF_LOCK_index: 40: ~23s of incomplete data

Most of the time, it seems that

• all or a part of  the TolmFrameBuilder servers  running in the rtpcs are unable to transmit theirs frames
• idem for the Imaging servers
• all or a part of the SlowFrameBuilder servers running of the olsever50 are unable to transmist theirs requests or  receives the replies too late

Up to now , the reasons of these events remain unknown

The detail of each event  is avalaible in  the related attached file

ITF found locked with Autoscience activated. It remained locked for the whole shift.

Guard tours (UTC):

- 18:55 - 19:30

- 21:30 - 22:05

- 00:30 - 01:05

- 03:25 - 04:00

The ITF kept SCIENCE mode all the shift.

20:02 UTC: S250119cv

Guard tour (UTC):
13:30 - 14:05
16:05 - 16:42

Today, I found ITF in SCIENCE. 22:46 UTC iTF unlocked. 23:33 UTC ITF back in SCIENCE.

Guard tours (time in UTC)

• 21:40-22:15;
• 0:35-1:10;
• 3:25-4:00;

ITF found DOWN in TROUBLESHOOTING mode due to the failure of INJ system. Gosselin and Chaibi fixed it at 16:00 UTC (see dedicated OnCall intervention entry). 
While we waited for the correct values ​​of PMC transmitted power and RFC low power, I contacted the TCS expert to check the Power_DAS_IN which in the meantime had dropped out of the threshold. D. Lumaca check the powers and performed a small waveplate rotation. I centered the DMS threshold in the new value.

Relocked at 17:50 UTC after the usual cross-alignment in ACQUIRE_DRMI (SR - 2urad ty-). SCIENCE mode set.
18:37 UTC unlocked (TBC). Autoelocked at 19:29 UTC. AUTOSCIENCE.

21:00 UTC - CALIBRATION mode for:
- CHECK HREC
- ISC injections (inject_SSFS.py)

Guard tour (UTC):
13:10 - 13:49
16:00 - 16:40
19:25 - 20:08

The following report has been submitted to the On-call interface.

On-call events -> Injection System

Title: SL cristal controller failure

Author(s): gosselin, gherardini

Details:

This morning I have been called by Fabio because the slave laser switched off. After investigation it seemed that the culprit was one of the temperature controller.
I came on site and went in EER with Fabio. It appeared that the controller for the crystal 1 was indeed not working. We started to swap it with a spare one. Setting the good parameters is not an easy task. The procedure is explained in the log entry 62780.
Some additional info about this procedure for the next time it occurs :

- To access the first menu one need to switch the PID ON and the 5 first seconds push simultaneously the two buttons on the right.
- When in the first or second menu, DO NOT push simultaneously the two buttons on the right. It makes the PID enter in a default mode with the display not properly working. To access the third menu it is better to switch it off, wait more than 10 s and then push on the simultaneously the two buttons on the right.
- LOC = 10 to deblock
- Not sure about the adress parameter but should be 1 2 3 or 27.

PID :
#Z131010... 008... => faulty one that was installed
#562 => display in default mode.
#560 => Installed now

When we finished with the PID controllers and checked that they were correctly working, we noticed that even if they were sending corrections the temperature of the pumping diodes and the crystals were not changing.
We suspected that the power supply of the peltiers was not working properly. With the help of Walid from remote we did some test and finally noticed that it was off... When arriving in the morning it was ON and working properly. Maybe the security chain somehow switched it off at some point of our intervention.

With the power supply ON again I started to increase the pumping diodes of the SL but the security triggered again. Most likely because the temperature of crystal reached 25 degrees. There might be an alarm not correctly set in the crystal 2 PID. I set the set point to 24 degrees (as it was this morning) and managed to recover the SL at full power.

I also recovered the neovan and slightly after the PMC relocked. We had to wait about 2 hours for everything to thermalized before going on with the lock acquisition (see plot).

To be noticed that, with the same parameters, the power at the output of the neovan is lower than this morning. 0.345 instead of 0.36 (see plot 2). This would need to be investigated later.

* Note that any files attached to this report are available in the On-call interface.

Nicola called me because the flag from TCS_NI_CO2_PWRIN got RED. At 16.30 UTC, I connected and checked the CO2 powers (since trouble shooting mode was set for INJ activities - 66001, 66002). The NI CO2 DAS inner ring was a little lower than reference: I made a really small waveplate rotation to bring the level to the reference one.

Since the DMS flag continued to remain in RED condition, I asked Nicola to center the thresholds around the current value of TCS_NI_CO2_PWRIN.

ITF found in Science mode with wind activity .

It unlocked at 22:14 UTC (wind activity sudden increasead); at the next relock I had to manually realign NE mirror.

Science mode was set at 23:06 UTC; it remained in Science for all the shift.

Guard tours (time in UTC)

19:19-19:45; 21:55-22:30; 0:55-1:30; 3:35-4:10; 5:00-5:30

Today, I found the ITF in CARM_NULL_1F, and the status was BAD_WEATHER due to strong wind activity. The ITF was in SCIENCE mode at 14:19 UTC. It was unlocked at 14:48 UTC and returned to SCIENCE mode at 15:39 UTC. From 17:34 to 17:35 UTC, the ITF was in ADJUSTING mode to allow P. Ruggi to restore the positions of NE and WE. The ITF remained in SCIENCE mode for the rest of the shift. 

Today we have move the end mirrors by 3mm in the horizontal direction in a common way. The displacement of the mirrors was done around 10:30 UTC when the interferometer was unlocked, and the mirrors have been returned to their normal position with a 1 hour long ramp starting from 17:35 UTC. In the middle of that tests the wind speeds were high preventing stable locking for several hours.

Figure 1 shows the trend of data during that test. On the first longer relock around 14:30 UTC, the power in the arms was higher by a few percent and so was the DARM optical gain. But this was not reproduced at the following lock. Looking at the time when the mirror position was returned in a smooth way from 17:35-18:35 there has been no change in arm power nor in DARM optical gain. This would mean that the change in power seen during offset changes on the mirrors is due to a point absorber on west end.

Figure 2-4 compare the beam camera images for three different times, figure 2 on Wednesday when the offset on the beam centering was put in place, figure 3 this morning at the normal mirror position without offset, and figure 4 in the middle of the day with the mirror moved by 3mm. The camera image barycenter was indicating that on Wednesday and today the beam was moving in opposite directions, but looking at the camera image the beam is moving in the same direction (once with the mirror and once by itself). What maybe confusing the image barycenter is the bright spot in the bottom left corner of the image which must be some reflection in the viewport, which changes brightness. So the mirrors were moved in the correct direction.

Looking at the camera images the aluminium markers on the baffle are much brighter on WE than on NE. This could be the explanation of why there are more issues with scattered light on WE, if there is more scattered coming there, for example from WI (or scattered light from WE reflected by WI back towards the baffle on WE).

During the ~30 minutes before the unlock we had the B1 PDs saturating in several occasions, causing SR and Range glitches (with the average wind speed not changing dramatically). However, only at the very end (when the truck moved around CEB) we can see a sharp increase in the seismometers' signals, and the corresponding large increase in the F0 corrections on the CEB suspensions; the PR and BS ones saturated right before the unlock (Figure and zoom).

The unlock around at 9:58 UTC may not have been caused by the truck trailer and excavtor but by the sudden increase in wind speed.

Figure 1 shows that in the preceeding 20 minutes there were two steps in SR alignment. These are usually caused by saturation of B1 photodiodes audio signals, which spoils the dither based SR alignment signals, causing a kick in the SR alignment. Usually after a few kicks like these during bad weather the interferometer unlocks.

ITF found in LOW_NOISE_3 in SCIENCE mode. 
Under request of C. Fabozzi, In agreement with Run and Commissioner coordinators, at 09:51 UTC I set ITF in ADJUSTING mode in order to allow the passage of a truck trailer with excavator around the central area (north direction) at a walking step.
Unfortunately it caused the ITF unlock and the opening of SPRB_SBE loop. Properly closed via VPM.
After the unlock Ruggi performed a COMMISSIONING activity moving end mirrors ~3 mm, with ITF in LOCKED_ARMS_IR. Acivity concluded at 10:50 UTC.
Wind activity increasing (fig1). Relocking in progress, BAD_WEATHER mode set.

In this weather conditions ITF reached LN3 without particulary difficults but it also unlocks without particulary difficults...

SBE
10:29 UTC - SQB2_SBE loop opened due to the misalignment of vertical position. Recovered via stepping motors.
DMS reports a residual drift of horizontal actuators so I left the horizontal loop opened.
Expert informed.

ITF found in relocking phase.

Science mode was set at 22:44 UTC; it remained in Science mode all the night.

Guard tours

18:50-19:25; 21:30-22:00; 0:20-0:55; 3:25-4:00

Today, I found ITF in LOCKED_ARMS_IR, and the status was BAD_WEATHER due to strong wind activity. At 16:25 UTC, we managed to relock at LOW_NOISE_2, and at 16:40 UTC, COMMISSIONING activities started. 19:10 UTC ITF back in SCIENCE. 19:34 UTC ITF unlocked and back in SCIENCE at 20:25 UTC. 

21:54 UTC ITF unlocked, left in relocking acquisition.

preliminary entry. detailed report will be posted tomorrow.

given the models that we recently designed, today we worked on the blending strategy for BStx loop in full bandwidth, in order to investigate the coupling with the PRtx loop at 1.2 Hz.

• we tested a new blending HP-LP (higher order with poles at 3.11 Hz). We tried it in LN2, by hand. The full bandwidth transition worked fine, but the 1.2 Hz oscillation is still there.
• by looking at the data we think that the calibration weights between the LF and HF signals might be wrong of about a factor 3. We performed some lines injections at 1.6 Hz and 5.8 Hz both on BS and PR driving. We will use this measurements to better characterize the loops.
• with the new blending we explored new weights for B4 branch, by reducing it of about a factor 10 (situation similar to have only a Low-passed B1p error signal in loop). In this case we didn't noticed any major change in the signals, and also on the amplitude of the 1.2Hz. We also increased the weight of almost a factor 2 with respect to the nominal one, with the result of slightly get worse with the 1.2 Hz instability (note that in the past, the same test with the former blending at 2 Hz, caused a higher increase of the oscillation). 

data have to be better analyzed but we think we can improve the situation working also on the main controller for BStx.

at the end of the activity we reversed everything and we put the nominal weigths and the usual belnding filters.

Following the measurement made during the maintenance, here are plots of the evolution of the power from 0.3W to 2.2 W for each PCal sensors.
The first 3 plots are without the control loop and the next 3 plots are With the control loop.

ITF found relocking (CARM_NULL_1F) in TROUBLESHOOTING mode. Unfortunately at 06:20 UTC it unlocked at ACQUIRE_LOW_NOISE_3 probably due to the strong wind activity (TBC).
The issue on ALS seems to be solved, so I exit from TROUBLESHOOTING mode and set directly BAD_WEATHER mode, ITF unlock sistematically at LOCKING_CARM_MC_IR. ALS expert tuned a bit ALS alignment.
ITF reached LN3. SCIENCE mode set at 08:53 UTC but unfortunately ITF unlocked at 09:15 UTC.
With commissioners we decided to keep ITF in LOCKED_ARMS_IR waiting for the wind to calm down.
BAD_WEATHER mode.

Other
(16-01-2025 07:30 - 16-01-2025 08:30) From remote
Status: Ended
Description: ALS
ITF unlocked sistematically at LOCKING_CARM_MC_IR. According with ISC crew we agreed that it could be a problem correlated with ALS alignment.
Van de walle is looking on it...