Shift in progress
ITF found in LOW_NOISE_3_SQZ and in Science Mode.
At 18:30 UTC I set the ITF in CALIBRATION Mode to perform the planned measurements:
ITF back in Science mode from 19:16 UTC.
Guard Tour (UTC):
14:05 - 14:55
15:57 - 16:32
DAQ
The process FCIM_MotSwitch stopped working at around 17:41 UTC. Process restarted via VPM at 17:44 UTC.
The ITF kept science mode all the shift.
Guard tours (UTC):
05:55 --> 06:30
08:00 --> 08:35
09:48 --> 10:33
11:55 --> 12:30
Nice find. Figure 1 and 2 made using omicron-plot show that these glitches in the WI MAG started at the same time as the glitches in h(t) around 20:00 UTC, and that they have not been happening the day before, and have been happening since then. There are magnetic glitches between 150Hz and 200Hz that have stopped a few hours before the glitches at ~30Hz started. The two might be related.
Figure 3 shows that this glitches are not visible on the NI MAG. So it is likely that the issue is close to the WI.
Next steps should be:
UPV + VetoPerf point to the following channels (without the _0 which is added in UPV to label the corresponding veto):
V0 → V1:ENV_WI_MAG_W_0, vetoed clusters: 454 (80.927 %)
V1 → V1:ENV_WI_MAG_N_0, vetoed clusters: 452 (80.570 %)
V2 → V1:ENV_WI_MAG_V_0, vetoed clusters: 452 (80.570 %)
V3 → V1:TCS_WI_CO2_ISSIN_0, vetoed clusters: 172 (30.660 %)
V4 → V1:ENV_CEB_ELECTRIC_0, vetoed clusters: 121 (21.569 %)
See https://scientists.virgo-gw.eu/DataAnalysis/DetCharDev/users/narnaud/UPV/20240428_glitches/V1:Hrec_hoft_16384Hz/perf/vp.html#V0 -> Click here to expand -> Time-frequency trigger distribution: before/after veto.
In attachment the Omicron plots of h(t) and V1:ENV_WI_MAG_W, for comparison.
ITF found in LOW_NOISE_3_SQZ and in Science Mode.
From 13:07 UTC to 13:08 UTC I set the ITF in ADJUSTING Mode to allow Nardecchia to turn the WI waveplate (see report #64116).
At around 17:50 UTC I was contacted by the LIGO Livingston Control Room, which reported that both LIGO ITF would postpone the planned calibrations by 24 hours. In agreement with the Commissioning coordinator, the planned Hrec calibration and LSC injections are postponed until tomorrow afternoon.
ITF left locked.
Guard Tour (UTC)
13:01 - 13:29
15:01 - 15:29
17:50 - 18:20
19:41 - 20:20
A new noise is seen in the external magnetometer starting April 22 19:56 UTC. Figures 1 and 2. The noise has been detected and studied by Renato and Federico. Here is a report of the investigation so far.
The noise is impulsive, as seen in Figures 3,4,5. Observed in the time domain it consists of a carrier at about 8Hz switching on-off with a cycle of approximately 4.4s (0.23 Hz): on for 2.2s and off for 2.2s.
The noise is seen by all magnetometers site-wide. Internal magnetometers sees it a factor up to about 10 larger than the external "N" magnetometer, in Figure 6 and Figure 7 (the EXT_N magnetometer is the gray spectrum in all 3 plots). Magnetometers that see it a bit more intense are those close to NI, WI and WE towers.
A close look to the narrow spectral structure of the noise shows that it does not follow the mains, in Figure 8.
These hints suggest a DC-powered PWM source (Federico).
Bruco runs using ENV_NI_MAG_V as target, and EXCLUDING all magnetometers (ENV_*MAG*) channels, show that this disturbance is not coherent with any other ENV channel (https://scientists.virgo-gw.eu/DataAnalysis/DetCharDev/bruco/users/fiori/ENV_NI_MAG_V_1397853318_ENV/) with the exception of a small coherence with the ENV_CEB_ELECTRIC. In particular no coherence, nor evidence of the noise is seen in all IPS and UPS probes. No coherence is also measured with any other Virgo signal (https://scientists.virgo-gw.eu/DataAnalysis/DetCharDev/bruco/users/fiori/ENV_NI_MAG_V_1397853318/). While s is a good news for the interferometer, it does not help much locating the source.
Measurements will be done also to check for possible external sources, like it was for galvanic currents in the natural gas pipelines (https://logbook.virgo-gw.eu/virgo/?r=55542).
Nicola called me because the WI CO2 laser changed its state (see figure 1).
To address the change in the WI outer power, I first rotated the WI outer ring waveplate to recover the nominal power to be injected into the ITF (11.59 UTC-12.00.26 UTC ) (ITF in ‘adjusting’ mode). Then, I adjusted the WI chiller set point to return the laser to its usual operating point, in particular I decreased it by 0.01 degrees, from 19.02 to 19.01 (12.21.04 UTC). The BCK chiller set point has been changed accordingly. This action did not solve the problem; in fact, the direction turned out to be wrong.
Thus, at 12.41 UTC, I increased the chiller set point from 19.01 to 19.03 degrees.
Finally, the standard situation has been restored (see fig.2).
Upon arrival I found ITF in Science Mode (LN3_SQZ).
At 09:12 UTC ITF unlocked due to an earthquake in Japan with Mag 6.5 (fig2). L1, H1 already down.
ITF relocked, Science Mode back at 10:16 UTC.
ISC
The DMS reports a mistuning of B4_56MHz (LSC_SSFS_Err_DPHI) since few days. To be check. Plot (1). ISC expert present onsite informed.
TCS
After the relock the DMS notified a Power_DAS_OUT_is_out_of_range for WI CO2 and Beam_is_inside_ITF for CH PICKOFF (plot3). I alerted TCS OnCall.
At 11:59 and at 12:57 UTC I set in ADJUSTING for two minutes in order to allow Nardecchia to turn the WI plate and the WI chiller temperature setpoint.
Guard Tour (UTC)
05:03 - 05:29
07:01 - 07:27
10:56 - 11:24
As observed by Federico, the metronix magnetometer in MCB is having an issue starting from 2023 October 2 UTC 00:03:03 (Figure 1). The signal looks corrupted (Figure 2). This does not seem an issue with the ADC and neither with the driving electronics, since other channels sharing the same boards are fine. We will investigate further at next maintenance.
This fauty condition was not signalled by the DMS DeadChannel since the associated rms was smaller than the set threshold. The rms threshold has been updated (0.35 to 1 nT) and this channel temporary shelved.
Figure 1. From about 20:00 UTC yesterday there are many glitches in h(t) around 30Hz. The glitches between 18:00-19:00 UTC are normal, these are due to injections to measure coupling to h(t) of various of degree of freedom. What happens starting from ~20:00 UTC is in science mode, and needs understanding.
Figure 2 The SNR of these glitches has grown from ~15 to ~30 over 1 hour, and has been relatively steady since then. There were several unlocks since the problem started and the glitches have continued at the same SNR after the relocks.
UPV + VetoPerf point to the following channels (without the _0 which is added in UPV to label the corresponding veto):
V0 → V1:ENV_WI_MAG_W_0, vetoed clusters: 454 (80.927 %)
V1 → V1:ENV_WI_MAG_N_0, vetoed clusters: 452 (80.570 %)
V2 → V1:ENV_WI_MAG_V_0, vetoed clusters: 452 (80.570 %)
V3 → V1:TCS_WI_CO2_ISSIN_0, vetoed clusters: 172 (30.660 %)
V4 → V1:ENV_CEB_ELECTRIC_0, vetoed clusters: 121 (21.569 %)
See https://scientists.virgo-gw.eu/DataAnalysis/DetCharDev/users/narnaud/UPV/20240428_glitches/V1:Hrec_hoft_16384Hz/perf/vp.html#V0 -> Click here to expand -> Time-frequency trigger distribution: before/after veto.
In attachment the Omicron plots of h(t) and V1:ENV_WI_MAG_W, for comparison.
Nice find. Figure 1 and 2 made using omicron-plot show that these glitches in the WI MAG started at the same time as the glitches in h(t) around 20:00 UTC, and that they have not been happening the day before, and have been happening since then. There are magnetic glitches between 150Hz and 200Hz that have stopped a few hours before the glitches at ~30Hz started. The two might be related.
Figure 3 shows that this glitches are not visible on the NI MAG. So it is likely that the issue is close to the WI.
Next steps should be:
ITF found in Science mode.
Sstarting from 22:40 UTC a series of local earthquakes unlocked many times the ITF:
The ITF was back in Science mode at 1:42 UTC, still in Science at the end of the shift.
Guard tours (time in UTC)
from 21:50 to 22:20; from0:00 to 0:30; from 2:00 to 2:30; from 4:00 to 4:30
In this afternoon shift science mode stopped from 16:00UTC to 19:02UTC for daily calibration and commissioning (PRCL offset scan and ISC noise injections) and for troubleshooting from 14:45UTC to 14:48UTC to solve the problem with Hrec; the ITF unlocked during the commissioning and it relocked at the first attempt.
- guard tours(UTC):
17:40 --> 18:10
19:40 --> 20:10
ISC
- 18:24UTC: LSC injections (inject_lsc.py);
- 18:40UTC: ASC injections (inject_asc_test.py);
because of a lack of time injections on SSFS and PSTAB not done, it will be run tomorrow afternoon;
Other
from 14:07UTC to 14:45UTC we had a strange behavior of Hrec with the range going up and down randomly and the sensitivity too, it was because of a test done by Alain on a test version of Hrec that by mistake was writing in a wrong shared memory.
Offline Hrec test setup
While installing an offline Hrec test setup in the CascinaTest Cm domain, this afternoon I duplicated the Hrec configuration, updating the FD_IN parameters but forgotten to update the FDOUT ones .As consequence, when I started this offline server on the same host where the online Hrec server is running (olserver52), there were some troubles with the Hrec online data .I didn’t realize it was creating problems as I was working with offline data and in the CascinaTest Cm domain. When I realized this , I contacted the Control room and I fxed the issue .
This issue started at 2024-04-26-14h08m02-UTC and was fixed at 2024-04-26-14h40m34-UTC
Doing a PRCL offset scan to minimize the frequency to amplitude coupling at the input of the interferometer: https://git.ligo.org/virgo/commissioning/commissioning-tasks/-/issues/12
Starting after the calibration measurements between 16:00 and 16:15 UTC. The steps are done at a speed of ~1 unit of PRCL per 20 second.
16:22 UTC (5min) PRCL_SET = 1.0
16:28 UTC (5min) PRCL_SET = 2.0
16:35 UTC (5min) PRCL_SET = 4.0
16:42 UTC (5min) PRCL_SET = 6.0
16:51 UTC (5min) PRCL_SET = 0.0
17:00 UTC (5min) PRCL_SET = 6.5
17:07 UTC (5min) PRCL_SET = 6.2
17:16 UTC (5min) PRCL_SET = 12 - interupted by unlock just after 17:18:40 UTC
just after reaching LN3
18:10 UTC (5min) PRCL_SET = -6.0
18:17 UTC (5min) PRCL_SET = 0.0
Figure 1 summarizes the scan done up to the unlock, PRCL_SET ~ 6 correspond to zeroing the frequency to amplitude conversion by the interferometer as seen on B2. It also shows that adding the offset in PRCL reduces the 6MHz gain as seen on B4 12MHz by 2%.
Figure 2 compares the time with the frequency noise coupling to minimized (blue) to the normal situation (purple). The B2 noise is 10 times lower between 1Hz and 3Hz, and it is also lower above 1kHz where the frequency noise is dominant. In between B2 is dominated by the pole at ~500Hz noise, subtracting it using B5 or B4 could reveal more clearly the improvement in coupling of frequency noise to B2 at other frequencies. There is no wideband impact on the h(t) noise.
Figure 3, 4, 5 show that the frequency noise lines (227Hz, 1111Hz and 3345Hz) are a factor ~30 lower on B2, and about a factor 2 lower in h(t).
Figure 6 my impression is that the coupling of frequency noise to h(t) becomes lower because for SSFS_LF the I and Q quadratures become more overlapped, so the BS TY minimizes both at the same time, and for SSFS_LINE the I and Q quadratures (that are very correlated), become of equal magnitude but opposite sign.
I wonder what it means that the frequency to amplitude noise coupling is zeroed, while the sideband gain decreases. Does it mean that the sidebands are not well tuned to the length of PRCL, and we need to choose to have carrier well resonant or sidebands well resonant?
Figure 7 the coupling of frequency noise to B2 has been quite stable since the beginning of the run
Figure 8 shows the PRCL offset scan done just after the unlock. This scan went with the same magnitude but in the wrong direction for the frequency to B2 noise coupling, and this time it increased the B4 12MHz mag signal by ~1.3%. So it points towards the current working point being in between being good for sideband gain and being good for the frequency to amplitude coupling at the interferometer input. That would intuitively make sense if the sideband frequency doesn't match the PRCL length, and the RF error signal that is the between sideband and carrier finds a working point in between being good for the carrier and for the sideband.
Last Tuesday the balancing of BS MAR Z actuation has been corrected in order to remove a small residual coupling vs TY, observed in windy condition. New data with some wind has been acquired and compared to older data with the same wind (fig 1). The effect is visible in fig 2: a very similar Z correction produced a much smaller BS TY fluctuation. A benefit in terms of CMRF fluctuation is also visible (fig 2). After the adjustment of the balancing, no coherent coupling from Z CORR to TY CORR is measurable anymore (fig 3).
Offline Hrec test setup
While installing an offline Hrec test setup in the CascinaTest Cm domain, this afternoon I duplicated the Hrec configuration, updating the FD_IN parameters but forgotten to update the FDOUT ones .As consequence, when I started this offline server on the same host where the online Hrec server is running (olserver52), there were some troubles with the Hrec online data .I didn’t realize it was creating problems as I was working with offline data and in the CascinaTest Cm domain. When I realized this , I contacted the Control room and I fxed the issue .
This issue started at 2024-04-26-14h08m02-UTC and was fixed at 2024-04-26-14h40m34-UTC
ITF found in LOW_NOISE_3_SQZ and in Science Mode, it kept the lock for the whole shift.
given that the past injections performed on CARM SLOW loop through the automatic script in /virgoDev/Automation/scripts/LSC/inject_lsc.py were not sufficiently accurate (fig.1), today we increased of a factor 5 the noise amplitude. If this noise amplitude is not enough, we could increase it even further, there should be margin, see fig.2 and 3.
Looking at the ISC_Fb logfile, one can find these 2 messages:
According to these 2 messages, as the frame building is done at 5Hz, it seems that
This plot at its zoom show the LSC_PR_Z_CORR and Sc_PR_MIZ_LSC_CORR for the 2024-04-26-02h22m33 event where
Related the 2024-04-13-19h35m32 Sc_PR event
ISC_Fb logfile report
This plot show the LSC_PR_Z_CORR, Sc_PR_MIZ_LSC_CORR and others Sc_PR channel for this event where
Errata corridge: the plot of the squeezing level and the BLRMS of the first CC scan (t_start = 16:52 UTC) was erroneously equal to the one of the second CC scan. I attach the correct plot.
ITF found in Science mode.
The ITF unlocked at 2:22 UTC and the unlock seems to be correlated to a problem of DAQ/PR; see attached plot and the log file of ISC_Fb:
2024-04-26-02h22m33-UTC>ERROR..-[TfbSource::StoreData] producer Sc_PR: overflow at GPS 1398133371.999912050 (received 2021 / expected 2000) (1323 times)
This kind of behaviour is something similar to what already reported in the entry: 63958.
At the next relock the lock of the CITF took more than 30 minutes (I also performed the manual prealignment twice); once the CITF was locked LN3_SQZ was achieved at the first attempt and Science mode was set 3:58 UTC.
Gurad tours (time in UTC)
From 21:30 to 22:00; from 23:30 to 0:00; from 1:30 to 2:00; from 3:15 to 3:34.
The ITF kept the lock all the shift, science mode stopped from 16:00UTC to 18:45UTC for calibration.
- guard tours(UTC):
13:01 --> 13:44
15:06 --> 15:34
17:50 --> 18:20
19:51 --> 10:22
Calibration
- 16:01UTC: Measurement of checkHrec, NE,WE,BS,PR,SR optical responses, and sensitivity (CALIBRATED_DF_SENSITIVITY);
- 17:48UTC: Measurement of actuators response for NE,WE actuators and NI,WI,BS marionettes (CALIBRATED_DF_PCAL);
DAQ
VPM stopped to work at 15:38UTC, process restarted.
A question is if the optical gain for differential signals created inside the CITF is different from the DARM optical gain as a function of SR alignment. The 56MHz optical gain which involves being recycled by SR is not affected by the SR misaligment, because the ~1.5urad SR misalignment is small compared to the ~12m length of the CITF, and the CITF is marginally stable. Is it the same for differential perturbations created by the BS?
Figure 1 shows a lock acqusition, with SR aligned at the beginning (pole at 400Hz) and then 10 minutes later misaligned (pole at 200Hz)
Figure 2 shows three times, 21:10 UTC with SR still aligned (purple), 21:20 UTC with SR misaligned (red), 21:30 UTC with SR aligned (blue)
Figure 3 zooms on the BS drum mode (1872Hz VIR-0476A-16 https://tds.virgo-gw.eu/?content=3&r=12696). It is decreasing over the 10 minutes of SR misalignment, but then in the following 10 minutes is decreases again by the same fraction in h(t). Hence this decrease is not a change in optical gain, but just the drum mode damping. Meanwhile on B1 the first step is clearly larger, as the optical gain at high frequency changes due to the SR misalignment. So it seems the optical gain evolves the same way as the DARM gain. And there is no strange effect that the SR recycling work differently for perturbations created in the CITF and perturbations created in the arms.
Shift in Progress
ITF found in LOW_NOISE_3_SQZ and in Science Mode, it kept the lock for the whole shift.
Guard tour (UTC):
7:02 - 7:29
9:01 - 9:27
11:01 - 11:28
DAQ
During the shift the VPM stopped working three times (9:19 UTC, 9:57 UTC, 10:52 UTC). In all cases, it was possible to restart the VPM following the procedure provided by Pacaud.
I attach the plots for the two CC phase scans performed during the shift of yesterday. I was not able to produce the BNS range plot for the second scan, which is anyway visible in Fig.4.
The second scan started at 18:11 UTC, with the same duration times of shot and CC scan as of the first one.
