Reports of 59143
Virgo Runs (O4b)
gherardini - 22:53 Tuesday 23 July 2024 (64772) Print this report
Operator Report - Afternoon shift

The work on SDB1 went on all the afternoon, activity stopped at 19:30UTC; other activities:

- SUSP: measurement on NE suspension from 14:30UTC to 17:15UTC (Boschi);
- ENV: environmental noise investigation in central building from 14:30UTC to 16:30UTC (Fiori, Paoletti, Tringali):

I left the cavities locked on the infrared.

Sub-system reports

Other
at 16:44UTC the SNEB position loop was opened by the guardian, controls properly closed.

SUSP
SDB1 suspension controls opened at 14:15UTC.

Images attached to this report
AdV-DET (Commissioning)
demagny, gouaty, spinicelli, nardecchia, magazzu, gherardini, pasqualetti, menzione, vacuum team - 22:37 Tuesday 23 July 2024 (64768) Print this report
SDB1 intervention: Day 1

This morning we took some alignment reference before starting the intervention on SDB1, using the NI single bounce beam.

We started by re-enabling the OMC temperature control. In order to avoid the loop to oscillate we reduced the gain from 50 to 20 at line 641 of the OMC configuration file:

ACL_FILTER_SET    OMC1_Peltier_stab_flt    4    20    1e-4    8        # gain under vacuum 50

The OMC temperature stab loop is enabled from ~7h27 utc.

Tower opened around 7h30. Nitrogen flux at graduation 1.0 on the regulator of the nitrogen bottle.

We tried to close the B5 drift control but it was not working. Looking at the B5 camera we see only scattered light patterns and no clear beam.

We tried to enable the High band width control, which initially seemed to help to reduce the bench motion, until the bench got excited. So we switched if off.

Air flux for the overpressure in the tower was put off at 08h45 utc to reduce the bench residual motion.

We adjust SDB1 angular position to center the beam on B1p camera. This is helping a lot in getting rid of secondary beams initially seen on the camera. We adjusted some temporary angular setpoints at -30 in TX (old value written in the config file was 30 urad) and at 0 in TY (old value 90 urad) to achieve the beam centering on the camera.

OMC shutter opened at 09h14 utc, then we opened also the B1_PD1 and B1_PD2 photodiodes.

Taking reference for B1p and B1s images in these conditions (see Pictures 1 and 2) :

B1p: Pos X: 0.507 mm, Pos Y: 0.218 mm, Fit X: -0.0078 mm, Fit Y: 0.176 mm

B1s: Pos X: 0.059 mm, Pos Y: 0.0613 mm, Fit X: -0.024 mm, Fit Y: 0.061 mm

OMC temperature scan started at 9h40 utc (B1p power between 4.5 and 5 mW)

TEM00 power: 1.2 mW (22.587 °C) (see Fig.3)

order 1: 0.54 mW (22.605 °C) (see Fig.4)

order 2: 0.45 mW

Scan stopped at 10h00.

Closing OMC shutter, Photodiodes B1_PD1 and photodiode B1_PD2 closed at 10h10 utc

Hartmann beam alignment check:

Ilaria took a measurement with the Hartmann wavefront sensor in the NI  configuration, but no beam was seen on the camera (see Figure 5). Andrea relocked the arms to realign the input mirrors, done at 10h50. After that we scanned the SDB1 angular setpoints to try to improve the Hartmann beam, but moving the SDB1 bench did not change the image observed on the HWS camera.

We decided to check the Hartmann beam inside the detection tower. Before accessing the tower Antonio closed the north arm valve so that no beam was reaching the detection, and the tower overpressure was restarted.

We observed the injected Hartmann beam on SDB1, with the bench suspended and controlled in air. The beam is clearly visible between the dichroic mirror and the parabolic mirror MMT_M2. We will use this beam to check that the beam dump is well positionned at the end of the work.

Start of SDB1 tower intervention:

We blocked the bench. Then we checked the functionning of the spare translation stage foreseen for the OMC shutter. The translation stage was working fine with commands sent from the VPM process SDB1_Rot, which allowed us to validate the cabling of these device. Then we proceeded with the replacement of this translation stage on the OMC shutter. After replacement of the translation stage, we tested again the functionning of the shutter. Initiially we found it was stuck in the open position, probably because of the pressure we applied on it during the remounting. After sending a couple of commandes to move the shutter by some fixed number of steps, the shutter was unstuck. We were then able to perform several cycles of shutter opening and closing without any issue. We leaver it in the closed position.

We closed manually the fast shutter and checked that its surface is clean. Then fast shutter was reopenned.

We then started to install an auxiliary fibered laser for alignment reference. This activity will be pursued tomorrow morning.

Images attached to this report
Virgo Runs (O4b)
amagazzu - 16:03 Tuesday 23 July 2024 (64767) Print this report
Operator Report - Morning shift

ITF found in LOCKED_ARMS_IR and in Upgrading Mode. At 6:00 UTC I set the ITF in Maintenance mode to allow the planned activities for the morning. Here a list of the action performed so far and their currest status:

- Preparatory work and Cleaning in Clean room for SDB1 Intervention (Menzione, Ciardelli, Gargiulo);
- Cleaning of Central Area (External firm managed by Menzione, Ciardelli);
- Replacement of SQB1 Hameg (Berni);
- Nitrogen refill with truck on site (External firm managed by Bazzi);
- Removal of NNC array and SAS accelerometer at WEB / NEB (Tringali);
- At 6:43 UTC, TCS Chiller Refill (Ciardelli);
- At 11:45 UTC, TCS Thermal camera reference (Magazzu);

At around 7:55 UTC the preparatory was concluded at, at 8:05 UTC, I set the ITF in NI Single Bounce configuration. DET Single bounce SDB1 check concluded at 10:05 UTC, DET-HWS beam clipping.
At 12:35 UTC the DET Crew moved inside the Central Building to verify the Hartmann sensor. Activity still in progress.

SBE
- During the night the value of SPRB_ACT_F0V increased above threshold. From 6:30 UTC to 6:39 UTC I acted on the related Motor3 to return the value around zero.
- At 7:01 UTC the Vertical loop of SQB1 Opened. From 7:22 UTC to 7:32 UTC I manually acted on the related Motor4 to return the LC_Y value close to its setpoints. Loop closed again at 7:28 UTC.

INJ
Since yesterday at 21:19 UTC the process Lnfs100 was reported as not working from DMS and VPM. I tried to restart the process via VPM but, upon further inspection, I found the process still alive on its machine (olserver129). This issues prevented the completion of fModErr at 6:31 UTC because INJ_MAIN was not able to gather data from the related process . At 6:52 UTC I manually killed the process and restarted it via VPM, after restarting FbsISC the data were available again.

SUSP
From around  2:23 UTC the flag max_Sc_SR_MAR_COIL_FLAG_50Hz_60 started to report an issue with the SR Marionette. From 9:14 UTC to 10:50 UTC I switched on the related Stepper Motors using PduServer to allow Ruggi to recover the mirror.

Images attached to this report
AdV-NNC (WEB)
Tringali, Paoletti - 14:47 Tuesday 23 July 2024 (64770) Print this report
WEB crane maintenance

Due to the crane maintenance on Tuesday 30th, some NN sensors (geophones and microphones) have been disconnected and displaced.

AdV-NNC (NEB)
Tringali, Paoletti - 14:46 Tuesday 23 July 2024 (64771) Print this report
NEB crane maintenance

Due to the crane maintenance on Tuesday 30th, some NN sensors (geophones and microphones) have been disconnected and displaced.

AdV-COM (automation)
bersanetti - 12:50 Tuesday 23 July 2024 (64769) Print this report
Comment to Automation set-up for the commissioning break (64764)

For the SINGLE_BOUNCE_NI configuration, I disabled the engagement of the SDB1 drift control.

Virgo Runs (O4b)
amagazzu - 8:19 Tuesday 23 July 2024 (64766) Print this report
Operator Report - Initial Status

ITF Mode: UPGRADING
ITF State: LOCKED_ARMS_IR
Quick Summary: SDB1 Venting in progress (see report #64765); DET and SR/BS Vacuum Large Valve closed; ISYS in standard state; SDB1 ID and LC open, all other Supension Loops closed; SDB2 Position Loop open to allow the tower Venting (see report #64761), SPRB F0V actuator close to saturation, alll other SBE Loops closed; Process Lnfs100 not working since yesterday at 21:19 UTC.
Activity ongoing: Preparatory work and cleaning under towers for SDB1 intervention (Menzione, Ciardelli, Gargiulo); Replacement of SQB1 Power Supply (Berni);

Images attached to this report
Virgo Runs (O4b)
menzione - 22:52 Monday 22 July 2024 (64761) Print this report
Operator Report - Afternoon shift

Upon arrival I found ITF in Commissioning Mode and in SINGLE_BOUNCE_WI.

At 13:39 UTC I set Upgrading Mode.

At 14:00 UTC I started the planned operations before the break of the vacuum of SDB1:
- ITF in DOWN, relock IR cavities, DOWN again.
- Verified that DET_MAIN metatron node status was in SHUTTER CLOSED, DET metatron node set in PAUSE.
- SDB2 suspension control opened via VPM process SDB2_SBE > Open Position Loop.
- Angular control loops of SDB1 opened via VPM process SDB1_LC > Marionette > Open Angular Loop.
- Suspension control loops of SDB1 (ID) opened.
- OMC temperature control switched off via VPM process SDB1_OMC > Temp Stab cmd > Disable (-1)

During the operations, the SQB1_SBE loop opened. According with SQZ expert, I closed it.

15:30 UTC ITF relocked in LOCKED_ARMS_IR. Still there.

Vacuum
SDB1 venting in progress (Vacuum team).

Susp
SR measurements done from 14:30 to 15:00 UTC (Boschi).

SQZ
Under request of DeLaurentis I recovered the vertical position of SQB2 via stepping motors.
I tried also to recover the FCIM loops but the horizontal position was far from the correct working point. According with DeLaurentis we decided to ask Bertolini to check on it tomorrow morning.

Images attached to this report
Vacuum (Detection)
Vacuum, Menzione - 19:00 Monday 22 July 2024 (64765) Print this report
DT tower venting

Today around 16h LT we started venting the DT tower

Notes:

  • the SR-BS valve is closed to block the beam and to provide isolation redundancy
  • the cleanroom supply air has been set to 'normal mode'
  • the tower air supply system is ON
  • extra noise is now produced in the CEB hall
AdV-COM (automation)
bersanetti, menzione - 18:24 Monday 22 July 2024 (64764) Print this report
Automation set-up for the commissioning break

This afternoon I put in operation a few modifications to the Automation, necessary for the planned interventions:

  • the node DET_MAIN has been verified to be in SHUTTER_CLOSED, then it was put in PAUSE and detached from the Management chain from ITF_LOCK (see #64761);
  • the node OMC_LOCK has been tentatively put in SHUTDOWN, but the state was not reached as the temperature control was already off and safe; it has been put in PAUSE and detached from ITF_LOCK;
  • ITF_LOCK has been modified in order to not act or check both DET_MAIN and OMC_LOCK, with some addition regarding the TCS; namely:
    • Removed WI and NI CH from DOWN and FMODERR_TUNED;
    • Removed DET_MAIN and OMC_LOCK from NodeManager;
    • commented the DET_MAIN block around line 390 in DOWN; forced self.FAST_SHUTTER_DEAD = False (which should not be used anyway);
    • commented the DET_MAIN block around line 430 in DOWN; forced state requests of other nodes in all cases outside such block;
    • commented the DET_MAIN block around line 592 in DOWN;
    • commented the state request to OMC_LOCK in DOWN;
    • commented all the execution statements of the shutter decorators for the paths: SINGLE_BOUNCE_[NI,WI], LOCKED_ARMS_IR, PRWI, SRNI, SHORT_MICH, MISALIGNED_END_MIRRORS; all other paths should be considered unsafe.

After the start of the SDB1 venting and the (unrelated) operation on SR we relocked the arm cavities, with no apparent issues. The diff file for ITF_LOCK.py is attached.

Non-image files attached to this report
Comments to this report:
bersanetti - 12:50 Tuesday 23 July 2024 (64769) Print this report

For the SINGLE_BOUNCE_NI configuration, I disabled the engagement of the SDB1 drift control.

AdV-TCS (CO2 laser projector)
nardecchia - 15:59 Monday 22 July 2024 (64763) Print this report
Comment to HWS-INJ measurement for WI DAS outer ring reference (64752)

This morning, a new measurement has been performed with HWS-INJ to confirm the measurement already done on Saturday 20th (64752).

All the actions are listed below:

-Manual unlock at 09.05 UTC.

-HWS-DET SLED switched OFF  

-HWS-DET SLED switched ON

The waveplates have been rotated to maximize the power on the outer ring line.

-09.05: WI OUT flip mirror closed 

-09.28:  WI CH flip mirror closed 

[No CO2 beams on CP].

ITF left with arms locked on IR for ~ 2 hrs

11.19 UTC: ITF in WI single bounce.
                  The illumination of the HWS before starting measurement is shown in fig.1 

11.21 UTC: HWS-INJ acquisition started (Folder 20240722T1321)
11.29 UTC: WI outer ring flip mirror opened (after WF 8).
13.25 UTC: HWS-INJ measurement interrupted

Two examples of HWS-INJ maps extracted from the two different measurements (today and Saturday) are shown in fig. 2.  
The measurement done during the heating phase also confirms what was observed in the previous measurement done during the cooling one, namely the vertical misalignment of the HWS beam on the CP.

Images attached to this comment
AdV-DAQ (Data Acquisition and Global Control)
casanueva, masserot - 15:49 Monday 22 July 2024 (64762) Print this report
LSC_Etalon_Acl running with Acl v1r27p17

The LSC_Etalon_Acl has been restarted with the latest Acl version  v1r27p17  at 2024-07-22-13h42m51-UTC  .

This new release allows

  • to reduce the logfile report of the ACL_CONST_CH variable updated by an Cm server
  • to perform a real Long DOUBLE(128bits) computation for an ACL_FILTER_CH channel
Virgo Runs (O4b)
gherardini - 14:58 Monday 22 July 2024 (64755) Print this report
Operator Report - Morning shift

This morning the science mode stopped at 8:13UTC to start the commissioning break; the work focused to take reference position data with hatman sensors (#64759), the ITF was manually unlocked at 9:04UTC; the work is still in progress.

Sub-system reports

SBE
SWEB position loop properly closed after adjusting the F1 vertical position with stepping motor.

Images attached to this report
AdV-COM (AdV commissioning (1st part) )
ruggi - 13:11 Monday 22 July 2024 (64760) Print this report
Unlocks due to Sc_NE_MIR_Z_CORR_LN huge value

A recurring typology of unlock has been identified. The pattern is always the same: the correction sent to NE MIR (Sc_NE_MIR_Z CORR_LN) passes in a couple of samples from to a normal value to a huge value (> 1e6) with no evident reason. The first event happened on April 27th; in 3 month one can count 12 of such events (fig 1). An example can be seen in fig. 2: when the correction get crazy, DARM is still good.

The correction sent to the DACs is an high-passed version of the locking signal computed by LSC (LSC_NE_CORR) and received by the DSP (Sc_NE_MIR_LSC_CORR). Comparing the two signals, which should be equal apart from a feq samples of delay, one can notice a small difference starting exactly at the time of the event (fig 3). My interpretation is that something fails in the communication to the DSP, but this is barely visible in the data because the DSP works at 40 kHz and the DAQ probes are re-built at 10 kHz. Supposing a sample at zero and doing the same filtering done by the DSP, a big value comes out, but not big enough the replicate the DSP output. We should imagine a different kind of corrupted data, or some other failure of the DSP computation. Moreover, a keep sample is already active in the DSP code.

In fig. 3 the time distribution of the events is shown. In the last month the rate has been about one event every three days. Experts should investigate, but given the low rate of unlocks, I would avoid too invasive intervetions, because things could even get worse...

Images attached to this report
AdV-TCS (Wavefront sensing)
nardecchia, spinicelli, gherardini - 11:37 Monday 22 July 2024 (64759) Print this report
HWS-DET reference before SDB1 intervention

This morning Piernicola went to the DET area to replace the HWS with the CCD.
Beam images have been acquired in different ITF configurations (see attached figure).

Images attached to this report
Virgo Runs (O4b)
Montanari - 6:58 Monday 22 July 2024 (64757) Print this report
Operator Report - Night shift

ITF found in Science, BNS Range ~55Mpc

SBE
At 01:50UTC the SWEB vertical position control loop opened by the guardian.
At the beginning I thought of taking the opportunity to restore the vertical position (adjusting mode between 02:07UTC and 02:21UTC) but then, given that with the loop open the sensitivity was still good and the BNS range too, to avoid risking an unlock I decided to leave the control open waiting for next one to restore it.

Guard Tourd (UTC):
21:20 - 21:50
23:20 - 23:50
01:30 - 02:00
03:20 - 03:50

Images attached to this report
Virgo Runs (O4b)
berni - 22:58 Sunday 21 July 2024 (64756) Print this report
Operator Report - Afternoon shift

ITF found in Science mode.

From 14:41 UTC to 15:44 UTC ITF in Troubleshhoting to fix the problem of the ACS MC; see ACS section.

 

ACS

At around 14:00 UTC the ACS on-call came on site; we went in the MC "intercapedine" and we found a broken belt for the fan of the chiller 1. At 14:41 UTC I switched to Troubleshooting mode in order to do fixing; at around 15:40 UTC we were able to restart the chiller1. The temperatura quickly returned inside the allowed thresholds, see attached plot.

 

SBE

The DMS is reporting that the vertical correction of SWEB is going to saturate; to be restored at the next unlock.

 

Guard tours (time in UTC)

13:16-13:46; 15:06-15:37;18:00-18:30; 20:05-20:35

Images attached to this report
Virgo Runs (O4b)
gherardini - 15:01 Sunday 21 July 2024 (64751) Print this report
Operator Report - Morning shift

The ITF kept the lock all the shift, science mode stopped from 12:06UTC to 12:08UTC due to squeezing disengage.


- guard tours (UTC):
4:52 --> 5:22
7:16 --> 7:46
9:17 --> 9:47
11:16 --> 11:47

Sub-system reports

Air Conditioning
at around 11:15UTC the MC hall temperature started to increase quite fast with some alarm from MC air conditioning system, after about half an hour the temperature slowly decreased (see plot); ACS on-call informed, situation under monitoring.

Images attached to this report
Virgo Runs (O4b)
Montanari - 6:56 Sunday 21 July 2024 (64754) Print this report
Operator Report

ITF in Science for the whole shift

Guard Tours (UTC):
21:30 - 22:00
23:30 - 00:00
01:30 - 02:00
03:30 - 04:00

Images attached to this report
Virgo Runs (O4b)
berni - 22:55 Saturday 20 July 2024 (64753) Print this report
Operator Report - Afternoon shift

ITF found in Commissioning mode for the activity HWS-INJ measurement for WI DAS outer ring reference.

The activity concluded at around 14:00 UTC; then the ITF was left 1h in locked arms to wait for the thermalization.

At 15:11 UTC I started to relock the ITF; the ITF relocked after a few attempts.

At 16:33 UTC ITF in Science mode.

At 18:22 UTC, after a glitch, I set Calibration mode to run the planned calibrations:

  • inject_asc_test.py
  • CALIBRATED_DF_DAILY

At 18:54 UTC ITF back in Science mode.

 

Guard tours (time in UTC)

13:00-13:30; 15:00-15:30; 18:00-18:30; 20:00-20:30.

Images attached to this report
AdV-TCS (CO2 laser projector)
nardecchia, gherardini, berni, lumaca, bersanetti - 16:34 Saturday 20 July 2024 (64752) Print this report
HWS-INJ measurement for WI DAS outer ring reference

In order to acquire some references before the WI CO2 laser replacement, three different HWS-INJ measurements have been performed.

Measurement #1

The illumination of HWS-INJ before starting the measurement #1 is shown in fig.1.

The list of the actions are listed below:

06.55 UTC: ITF manually unlocked and and arms locked on IR
07.53 UTC: WI single bounce configuration
07.58 UTC: START HWS–INJ acquisition  (Folder 20240720T0958)
08.08 UTC-08.12: Increase of the WI OUTER ring power. Completed at WF 14 .

Without piston and tilts, the OPL induced by the increase of the outer ring power is clearly visible in the HWS map. Unfortunately, the OPL is not visible without removing them (see fig.2). Since removing piston and tilt causes the centering information to be lost, between WFs 43-46, I rotated the waveplate to inject the total available power on the outer ring line. I completed this action at 08.46 UTC. I was able to increase the WI pickoff from 0.806 W to 0.904 W , thus the outer ring power from 2.2 W to 2.5 W. The situation didn't improve. To maximize the S/N ratio of the measurement, the only way is to perform the HWS-INJ measurement in the ON/OFF condition of the outer ring. In order to exclude any possible misalignment of the HWS beam on the CP, the WI CH power has been increased (between 10.02 and 10.04 UTC, WFs 120-122) [WI CH pickoff from 0.909 W to 2.8 W].
The OPL induced by CH appears in the HWS-INJ map, removing and without removing the tilt but the measurement result was not so clear (see fig. 3).
At this point, to avoid wrong interpretation of the results of the CH centering, a second acquisition has been performed (measurement #2).

I asked Fabio to relock the arms on the IR and put the ITF again in WI single bounce to perform a measurement during the cooling phase.
Then, I started a new measurement where the reference was taken with the outer ring at the steady state of maximum available power and CH at high power. The differential measurements were performed by closing the flip mirror of CH.

Measurement #2

The illumination of the HWS-INJ before starting this second measurement is shown in fig.4.

Here the list of actions:
10.53 UTC: HWS-INJ acquisition started (Folder 20240720T1253)
11.01 UTC: WI CH flip mirror closed (WF 9)

The OPL due to CH switching off appeared well visible in the map (see fig. 5). Thus, the HWS-INJ beam is quite well aligned in the horizontal direction, not so good in the vertical one.

At this point, I proceeded with the last measurement with HWS-INJ, taking the outer ring at the maximum available power as a reference condition. The differential measurements have been performed by closing the WI OUT flip mirror (measurement #3).
Between the end of the CH measurement and the beginning of the new one (to allow the thermalization of the CH off), the ITF has been left with the arms locked on IR.

Measurement #3
HWS-INJ illumination before starting the measurement is shown in fig. 6.

Here the list of actions:
12.11 UTC: HWS-INJ acquisition started (20240720T1411) in WI single bounce
12.18 UTC: WI OUTER flip mirror closed (WF 7)
13.48 UTC: HWS-INJ measurement interrupted (WF 93)

In this measurement, the HWS maps are more clear, the outer ring OPL is visible in the blue area in the lower part of the map (see fig. 7). 

Unfortunately, the HWS beam is quite misaligned in the vertical direction, making it extremely difficult to identify the centering coordinates.

At the end of the shift, I resettled all CO2 nominal powers (completed at 14.11 UTC).

Images attached to this report
Comments to this report:
nardecchia - 15:59 Monday 22 July 2024 (64763) Print this report

This morning, a new measurement has been performed with HWS-INJ to confirm the measurement already done on Saturday 20th (64752).

All the actions are listed below:

-Manual unlock at 09.05 UTC.

-HWS-DET SLED switched OFF  

-HWS-DET SLED switched ON

The waveplates have been rotated to maximize the power on the outer ring line.

-09.05: WI OUT flip mirror closed 

-09.28:  WI CH flip mirror closed 

[No CO2 beams on CP].

ITF left with arms locked on IR for ~ 2 hrs

11.19 UTC: ITF in WI single bounce.
                  The illumination of the HWS before starting measurement is shown in fig.1 

11.21 UTC: HWS-INJ acquisition started (Folder 20240722T1321)
11.29 UTC: WI outer ring flip mirror opened (after WF 8).
13.25 UTC: HWS-INJ measurement interrupted

Two examples of HWS-INJ maps extracted from the two different measurements (today and Saturday) are shown in fig. 2.  
The measurement done during the heating phase also confirms what was observed in the previous measurement done during the cooling one, namely the vertical misalignment of the HWS beam on the CP.

Images attached to this comment
Virgo Runs (O4b)
gherardini - 15:02 Saturday 20 July 2024 (64719) Print this report
Operator Report - Morning shift
This morning science mode stopped at 6:54UTC to start commissioning activity (WI CO2 centering measurement with hartman sensor); ITF unlocked manually, Ilaria worked with the ITF set the WI single bounce configuration and arms locked on the infrared from time to time to keep mirrors aligned, the work is still in progress...
Images attached to this report
Virgo Runs (O4)
menzione - 6:23 Saturday 20 July 2024 (64750) Print this report
Operator Report - Night shift

ITF found in LOW_NOISE_3_SQZ and in Science Mode.
At 23:54 UTC ITF unlocked (TBC). Relocked at first attempt. Science Mode set at 00:39 UTC.

DAQ
BaDAQ process crashed. I tried to restart it via VPM without success.

Guard Tours (UTC):
22:00 - 22:30
22:55 - 23:25
02:00 - 02:30
03:40 - 04:00

Images attached to this report
Virgo Runs (O4b)
irace - 22:56 Friday 19 July 2024 (64749) Print this report
Operator Report - Afternoon shift

Upon arrival, I found the ITF locked and in SCIENCE mode.

At 15:36 UTC the ITF unlocked. It relocked at the first attempt and returned to SCIENCE mode at 16:22 UTC.

 

Guard tours (UTC):

- 17:45 - 18:15

- 19:25 - 19:55

Images attached to this report
Detector Characterisation (Broadband noise)
fiori, tringali, paoletti - 17:37 Friday 19 July 2024 (64747) Print this report
Comment to Bump structure around 63 Hz (64575)

A comparison between B4 and Hrec. After July 16 the bump reappeared in B4 with similar characteristics, while in Hrec it is less much less evident.

Figure 2 compares Hrec, B4 and SPR accelerometer spectra at a time on June 29 and a recent time of July 18. The two times have been chosen such that the amplitude of the B4 bump is similar. 1hour average is used for both. The amplitude of the vibration noise, as measured by the SPR accelerometer, is similar for both times. The amplitude of the bump in Hrec is lower. The indication from this plot is that the coupling to B4 has not changed while the coupling to Hrec has reduced. We do not know what might have caused this reduction.

In Hrec, note the line at 62.4 Hz which seems to have a slow amplitude modulation (Figure 1).

Images attached to this comment
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