Today, starting in the morning we dismounted the IPATSiA setup from WE and brought it to TCS room in the central building. We tested the picomotors and discovered that the picomotor of the horizontal DoF of the last mirror (that points towards the payload) is not working (so it has to be moved by hand).
In the afternoon,we started the shift by ending the installation of the setup around the WI tower. However, we had some problems related both to the cabling of the sensors and the chiller used (the TCS spare, stored in the TCS chiller room).
At first, we couldn't get the temperature probe working (it seems related to the module ENV-TCSR2, to be investigated). We then decided to continue checking only the power, but unfortunately the chiller used could barely reduce the T of the water by 0.5 degree in ~1h.
To avoid any damage to the laser, we only used it for small period, checking the alignement towards the mirror. We moved by hand the picomotors in order to put the CO2-PA into the center of the mirror.
We ended the shift at around 18:20 in order to have the time to relock.
To be noted: when trying to get IPATSiA working, i.e. with us close to the tower, the ITF kept unlocking sistematically, that even if we weren't moving. We should understand wether this is a problem related to the several devices switched on or only to the human presence.
Different interventions were performed during today's maintenance.
-
Timing_DSP:
Underthreshold values were observed for Sc_SR and Sc_NI.
By rebooting the Sc_SR master board, we successfully resynchronized the DSPs with the GPS time.
The same procedure was applied to the Sc_NI master board; however, in this case, it was necessary to manually upload the hrd file, as data were not available after the reboot.
However, the timing issue still remains on Sc_NI and should be investigated jointly with DAQ team. -
WI, NI, PR vertical accelerometers centering:
The positions of the WI, NI and PR vertical accelerometers sensing elements were re-centered with motors
ITF found in LOW_NOISE_3 and in Science Mode wIth Autoscience On.
All times are UTC.
MAINTENANCE Mode set at 6:00. Activity during maintenance:
- Cleaning standard tour + FCIM and FCEM (Ciardelli/Menzione);
- 6:23 TCS Chiller refil (Ciardelli/Menzione);
- From 6:25 to 6:36 OMC Lock (Operator);
- From 6:40 to 7:02 OMC Scan (Operator);
- From 6:36 Excavator started working on flags basement;
- 7:09 ISC_Fb TolmFrameBuilder, see #67875 (Masserot);
- From 7:19 to 7:36 SR DSP Timing Issue (Palaia, Piendibene);
- From 7:13 to 9:26 INJ HVAC Injections, see #67876 (Soldani, Paoletti);
- 7:40 bashrc_Virgo, see #67878 (Carbognani, Seder);
- From 7:49 to 8:12 TCS Camera Reference (Operator);
- From 8:40 to 9:03TCS CO2 Power Check (Operator);
- From 8:53 to 9:45 NI DSP Timing Issue (Palaia, Piendibene);
- 9:33 TCS NI CO2 CH power adjustment (Cifaldi);
MAINTENANCE ended at 10:30.
EARTHQUAKE Mode set at 12:13,
EARTHQUAKE Mode ended and Autoscience engaged at 12:41.
ITF left in LOCKING_OMC_DARM_B1_PD3 with OMC unable to lock;
TCS CO2 Power Checks:
| CH [W] | INNER DAS [W] | OUTER DAS [W] | ||
| WI | Pickoff | 0.278 | 0.026 | 0.293 |
| NI | Pickoff | 0.697 | 0.056 | 0.507 |
Due to a change in the AC setpoint caused by the recent hardware replacement (see entry #67766), NI and PR filter temperatures were out of range. Since CEB temperature is now stable, DMS thresholds have been updated accordingly.
The modification introduces configuration changes specific to the new AL9 support.
Verification confirms that the existing CL7 environment remains unaffected by this update.
Today we tested some settings of the INJ HVAC system, in order to evaluate the noise increase inside the INJ lab.
This is the timetable (UTC) of the operations:
- 07:39:40 Set to "person present in lab" mode (leave all systems in automatic mode)
- 07:56:00 Switch back to "no one in lab" mode – 15 min
- 08:10:30 Keep extraction (return air) flow rate constant + increase supply air fan to 33 Hz
- 08:20:30 Keep extraction flow rate constant + return supply air fan to baseline value (~23 Hz)
- 08:30:20 Keep supply air flow rate constant + increase extraction fan to 30 Hz
- 08:45:20 Keep supply air flow rate constant + return extraction fan to baseline value (~20 Hz)
- 08:56:30 Increase both supply and extraction fan frequencies simultaneously by 10 Hz
- 09:10:30 Restore all parameters to initial conditions – end of test
A detailed analysis will follow.
It is worth noting that some acoustic noise was detected inside the INJ lab by the microphones. This could be a consequence of the maintenance operations carried out on the platform inside the CEB.
Also note that during the automatic setting at 07:39:40 UTC, only the supply fan was adjusted by the system.
Here the computation of the angular noise budget computed with the injections done on 29 September: all couplings look higher than in the recent past, especially DIFFp (both) and PR_TX, which looks impacting at low frequency. To be noted that this measurement was done before the recent PR MAR rebalancing.
The gwas pipeline makes use of adaptive decomposition (pytvfemd) to decompose a target time series (in this case, h(t)) affected by glitches, into oscillatory modes referred to as intrinsic mode functions (IMFs). The envelope of such IMFs, the instantaneous amplitude IA, is known to be well correlated to the predictor of the noise source (in this particular case, Sc_WE_MIR_Z). I attach results (glitch.png) obtained using the gwas pipeline, you should be able to reproduce results from this entry by running (minigwas is for single time intervals, gwas is for daily analysis using Condor):
./minigwas --gps 1441584048 --target V1:Hrec_hoft_16384Hz --seconds 60 --fs 100 --channels /users/longo/Desktop/single/sc_we_mir_z.txt --opath /users/longo/Desktop/ --thr -1 --imfs 1,2 --combos 1 --fl 25 --bwr 0.1 --bsp 26
where the .txt file contains the channel name V1:Sc_WE_MIR_Z (it can contain a long list of channels if you wanna do a "brute force search").
If I didn't make mistakes, having obtained the folder with the output of minigwas, running the glitch.py script I'm attaching you should be able to replicate the figure I'm posting. The pipeline is available on pypi, so you should be able to install it (feel free to email me if needed) by doing:
pip install gwas_tools (https://pypi.org/project/gwas-tools/)
git clone https://git.ligo.org/stefano.bianchi/gwpipelines
and editing gwas and minigwas, setting the right environments. To use gwas, you should also install pytvfemd (https://pypi.org/project/pytvfemd/) which is the Python version of tvf-EMD, developed by Stefano Bianchi.
As the glitch considered here was not persisting over the whole 60s interval considered, I selected relevant times of interest by hand after running the pipeline. This way, a higher correlation can be obtained using tvf-EMD (0.78).
Two nice features to add to minigwas could be:
1) the possibility to pass a channel name directly as input, without having to write a .txt file
2) the possibility to refine the analysis, focusing on smaller time intervals, while still allowing to run one single scan on a longer stretch of data (what I did by hand in this case). This, if glitches are separated in time, I think could increase obtained correlation.
If you're interested in the method you can see these papers:
Guillermo Valdes et al 2017 Class. Quantum Grav. 34 235009 https://doi.org/10.1088/1361-6382/aa8e6b
Alessandro Longo et al 2020 Class. Quantum Grav. 37 145011 https://doi.org/10.1088/1361-6382/ab9719
Alessandro Longo et al 2022 Class. Quantum Grav. 39 035001 https://doi.org/10.1088/1361-6382/ac4117
Stefano Bianchi et al 2022 Class. Quantum Grav. 39 195005 https://doi.org/10.1088/1361-6382/ac88b0
Alessandro Longo et al 2024 Class. Quantum Grav. 41 015004 https://doi.org/10.1088/1361-6382/ad0db0
Alessandro Longo et al J. Appl. Phys. 138, 090701 (2025) https://doi.org/10.1063/5.0273058
As trial to reduce the SUSP_Fb input data flow, this morning the data related to the TCS_ADC_Moni1 ADC7674 are now sent ot the ISC_rtpc instead of the SUSP_rtpc
- operation performed at 2025-10-07-07h09m53-UTC
ITF found in ACQUIRE_LOW_NOISE_3 and in Prepare_Science Mode. Back in Science Mode from 21:07 UTC.
It unlocked at 0:59 UTC, back in Science Mode from 1:43 UTC.
ITF left locked.
13:00 UTC ITF found in SCIENCE
13:16 UTC Etalon corrections reset
13:17 UTC ITF in SCIENCE
13:45 UTC EGO truck passage near CEB
15:30 UTC ITF in COMMISSIONING
15:34 UTC inject_lsc.py started
15:36 UTC data loss (SUSP_Fb). Injections stopped
15:41 UTC injections restarted (ended 15:57 UTC)
16:00 UTC ITF in CALIBRATION (measurements with ITF unlocked)
16:03 UTC CALIBRATED_DELAY (ended 16:18 UTC)
16:21 UTC CALIBRATED_PRWI (ended 19.03 UTC)
17:14 UTC while executing READY_DF_INtoEND_LN, signal from LSC_B7_DC was a flat line and NARM_LOCK showed usermsg "Waiting for arm power estimation". Contacted ISC on call expert, NE/NI mirrors had rotated when CALI node was put in DOWN up to a point that NARM was completely misaligned. Once realigned, ITF was kept in LOCKED_ARMS_IR for a few minutes to stabilize, as instructed by the expert.
17:45 UTC started again READY_DF_INtoEND_LN. Couldn't achieve the state and LN1 in time to run CALIBRATED_DF_INtoEND_LN - Measurement of actuators response for NI,WI mirrors skipped
18:24 UTC seismic noise on B4, B7 and B8, seismon flag red, locking attempt failed. B1p_QD1 and B1p_QD2 galvo loops opened and were closed
19:12 UTC ITF in SCIENCE
19:34 UTC unlock, followed by unlocks at CARM_NULL_1F and LOCKING_CARM_NULL_3F (three times), B1p_QD1/2 Vbias rearmed
Guard Tours (UTC)
17:52 - 18:30
20:54 -
ISC
(06-10-2025 19:02 - 06-10-2025 19:40) From remote
Status: Ended
Description: NARM misalignment during calibrations, multiple unlocks
Actions undertaken: NARM showing no triggers (WARM showing no problems) after CALIBRATED_PRWI. Realigned
Status: Ended
Description: Repeated unlocks
Actions undertaken: 400 Hz oscillation spotted on mirrors
The unlocks between CARM_OFFSET_STEP_3_OF_3 and CARM_NULL_3F, at UTC 20:01:16, 20:10:44, 20:19:49 all look the same (Fig.1).
PRCL, MICH, SRCL and several AA loops experience a very fast oscillation (400 Hz), further modulated by another one at 60 Hz over a few tenths of a second. The same oscillation is visible on the Z correction of the IMC.
Considering that these are rather anomalous frequencies for ISC loops, the IMC control might be the cause.
I was called because the North arm was too misaligned to show flashes.
I corrected the alignment of the test masses and re-locked the arm.
This morning the ITF unlocked at 10:14UTC, it relocked at the first attempt (science started at 11:03UTC); science mode stopped from 9:14UTC to 9:15UTC for adjusting (tune etalon stet point).
Sub-system reportsISC
- 9:14UTC: NI etalon set from 20.4 to 20.2, 86400 sec ramp time.
- 9:14UTC: WI etalon set from 20.8 to 20.63, 86400 sec ramp time.
ITF found in LOW_NOISE_3 and in Science Mode. ITF left locked.
Guard Tour (UTC)
22:05 - 22:41
0:38 - 1:03
3:08 - 3:42
DAQ
At 1:11 UTC the value of Hrec_Range_BNS jumped to 0 for around a minute due to missing data of SUSP_Fb.
13:00 UTC ITF found in SCIENCE, range oscillating between 8 and 50 Mpc, wind activity and sea activity flags red
13:16 UTC unlock, seimson flag also red.
13:38 UTC ITF set in BAD_WEATHER
17:41 UTC ITF in SCIENCE
19:35 UTC unlock (no ENV flags red), unsuccessful relock at LOCKING_CARM_NULL_3F twice
20:47 UTC ITF in SCIENCE
Guard Tours (UTC)
13:06 - 13:34
15:51 - 16:24
19:45 - 20:25
Air Conditioning
(05-10-2025 15:30 - 05-10-2025 17:20) On site
Status: Ended
Description: NEB air compressor 1 malfunction (see attached screenshot)
Actions undertaken: Entry 67865: Status of air comp 2 granted to be able to carry on through the night, air comp 1 broken and leaking oil was safely shut down, technician to be called tomorrow (Romboli)
Figure 1. The etalon control actuation has been saturating for the past 10 days for WI and past few days for NI. This is most likely due to the temperature in the CEB, that was decreased by ~1 degree by the change in temperature controller, and in addition to the decrease in outdoor temperature.
At the earliest occasion the temperature of both and WI and NI etalon set point should be reduced by one fringe for each of them to cope with the lower ambient temperature.
The following report has been submitted to the On-call interface.
On-call events -> Air Conditioning
Title: NE air compressor failure
Author(s): romboli
| Called at: 17:40, 05-10-2025, by: Zaza |
| Remote intervention: Started: ; Ended: |
| On-site intervention: Started: 18:25, 05-10-2025; Ended: 19:10, 05-10-2025 |
| Status: Resolved |
| Operator when issue resolved: Zaza |
Details:
I received a call from the operator regarding a drop in air pressure at the NE. I consulted with D. Soldani and we verified that even if one compressor was broken, the compressed air should be supplied by the twin compressor, even though the alarm flag indicated only one of the two compressors. I arrived on site and indeed, one of the two compressors was out of power and had a significant oil leak. I took steps to shut it down, disconnect it from the air circuit, and verify that the twin compressor was working properly. The technician will be called immediately tomorrow morning to repair it.
* Note that any files attached to this report are available in the On-call interface.
ITF found locked at LN3 in SCIENCE mode.
ITF unlocked probably due to the strong sea activity (plot1) at 21:59 UTC. Relocked at first attempt but with a bad BNS range. SCIENCE mode at 22:50 UTC.
It unlocked again at 01:09 UTC. After few unsuccessfully lock attempts, I set BAD_WEATHER mode.
ITF found in LOW_NOISE_3 and in Science Mode.
At 19:30 UTC I set the ITF in Calibration Mode and started the planned measurements:
From 19:30 UTC to 19:38 UTC - Check Hrec (CALIBRATED_DF_DAILY);
From 19:38 UTC to 19:53 UTC - ISC injections (inject_lsc.py);
ITF back in Science Mode from 19:57 UTC and left locked.
Guard Tour (UTC)
13:29 - 14:05
15:54 - 16:33
18:35 - 19:11
DAQ
At 16:26 UTC the value of Hrec_Range_BNS jumped to 0 for around a minute due to missing data of SUSP_Fb.
ITF in Science mode for all the shift.
ISC
Red flag for NI Etalon, experts informed by mail.
Guard tours (time in UTC)
21:20-22:00; 1:00-1:40; 1:30-2:10
ITF found locked at LN3 in SCIENCE mode.
13:23 UTC - S251003at
At 17:02 UTC ITF unlocked due to a strong earthquake occurred in Russia with Mag. 6.2, (fig1). EARTHQUAKE mode set.
At 18:04 UTC ITF relocked at first attempt at LN3 after a realignment of N cavity (NE ty+) and the usual cross-alignment in ACQUIRE_DRMI (SR tx+).
SCIENCE mode set.
Guard tour (UTC):
17:47 - 18:20
