ITF Mode: LOCKING, AUTORELOCK_FAILSAFE engaged
Quick Summary: IMC and RFC locked; all Suspension loops closed; all SBEs loops closed;
Activities ongoing: maintenance.
ITF Mode: LOCKING, AUTORELOCK_FAILSAFE engaged
Quick Summary: IMC and RFC locked; all Suspension loops closed; all SBEs loops closed;
Activities ongoing: maintenance.
Upon arrival I found ITF locked at LN3.
The planned activity on - Electronics and Software switch-off unnecessary devices (Nocera), VAC - warm up test on SDB1/SDB2 B1 viewport (Pasqualetti) started at 15:00 UTC and went on without problems till the end (at 19:00 UTC).
After the scheduled interventions, the ITF unlocked a couple of times for unknown reasons (TBC). Relocked easily at first attempt in both occasions.
No particular operations to report.
ITF left in AUTORELOCK_FAILSAFE - LOW_NOISE_3_SQZ.
Apologies if this is not the right section for this post.
In the preparation for O4, a switch-off campaign with the goal of getting rid of all potential noise sources we can live without is currently underway.
This afternoon, starting shortly after 18.00 local time the following units have been switched off/disconnected:
INJ - EIB Picomotors and Phase Camera piezo driver
SAT - all motor driver units on all towers (CEB, NE, WE)*
TCS - all HWS (INJ, DET, NI, WI, NE, WE) power supply, point absorber power supply and amplifier (TCS Room), CO2 piezo dfriver power supply (TCS Room), and PR-NI RH power supply.
* as requested, all NI cables have been plugged back in their respective units
Unless the ticks fool me, at 20 Hz the ASD is "a little more than" , and at 40 Hz something between and . This means a power-law exponent between
and "a little less than" .
At these frequencies, the glitch ASD could be affected by the noise background. We can move upward and repeat the estimate around the frequencies of the maximum intensity identified by omicron triggers, which is around 40 Hz. For example, from Didier's plot, the ASD is about at 30 Hz and at 70 Hz. This leads to a power-law exponent of -2.72.
This is somewhat midway between a step function, as explained by Michal, and an impulsive force, like a Dirac delta, whose response would have produced a power law with exponent -2. And, just looking at the math, an exponent of -2.5 could be the response of a "hyperbolic-step-function" of the form
...whatever may produce it.
This afternoon we switched off the controller of the main turbo at NE, suspected of somehow producing disturbances even when the pump is stopped .
Following a request from the commissioning team, today we warmed up the B1 viewport area by a few degrees Celsius, applying an heating band on the minilink and keeping + ~ 7°C for about 10 min (picture).
Timing: 17:05 LT started heating (one person in DET lab), finished at approx. 17:15 LT . Then left in free-cooldown
Since 2024-03-18-16h23-UTC the DET_B1p_DC, DET_B{2,4,5,7,8}_DC channels are stored with _DS suffix in the RAW and RAW_BCK streams
There was a missed update in the code of Metatron following this CALnoise configuration change: the NE,WE_PCAL_permline4 do not exist anymore, and the PCal lines around 995 Hz are now on NE,WE_PCAL_permline2. This line must be switched off when injecting noise on the PCal in order not to saturate the laser power. This has been fixed today in CALI_common.py, function disable_pcal_lines_HF(). ALso, in the file injector_classes.py, this function was called two times (one time with two calls to cm_send(CALnoise, 'AcParamSet'), the second one 1 s after the first one). It is now called only once, and without doubling the call to AcParamSet.
This morning the scope was to re-commission the scripts that inject noise on the LSC / ASC / SSFS loops. The LSC script was already ready, so we just run it to check that it was working properly. All the injections showed coherence with Hrec (SRCL wsa slighlty worse than the others, on Wednesday we would like to try a nosie injection at slightly lower frequencies 5-50Hz). The script can be found and launched at: /virgoDev/Automation/scripts/LSC/inject_lsc.py. Today's injections GPS can be found at /virgoData/NoiseInjections/LSC/LSC_injection-1394783415. Notice that during these injections the Galvo of B4 QD1 opened. To be checked if it was a coincidence or if this happens consistently.
Next activity was to inject noise in the angular loops closed on QPD error signals (Commp, DIFFp and PR) in order to adjust the amplitudes of the noise injected. Note that BR TX loop is also measurable but we mispelled the DOF name in the function to perform the injection (to be repeated on Wednesday)
Clean data: Same for the LSC noise injections.
ASC noise shape = Butterworth bandpass between 5 and 50 Hz.
GPS time stamps of the injections:
- 8.21.15 UTC + 120 sec, DIFFp TX inj ampl 8e-6.
- 8.32.10 UTC + 120 sec, DIFFp TX inj ampl 1e-4.
- 8.55.00 UTC + 120 sec, PR TX inj ampl 1e-4.
- 9.06.15 UTC + 120 sec, PR TY inj ampl 2e-4.
- 9.22.30 UTC + 120 sec, COMMp TX inj ampl 9e-4.
- 9.33.40 UTC + 120 sec, COMMp TY inj ampl 1e-3.
We also wrote a symmetric code in order to inject noise in these loops, and we tested it. It can be found at: /virgoDev/Automation/scripts/ASC/inject_asc_test.py. The .txt file with the measurements is stored in the folder 'virgoData/NoiseInjection/ASC/ASC_injection-*GPS*.txt'. We would like to finish with the BS TX on Wednesday, and then inject noise through the driving to the remaining angualr DOFs (SR and softs).
As side activity we performed an OLTF measurement of the BS TY loop through the DSP (HF brench, optical lever sensing), in order to have a response of the roll-off of the loop tf.
Noise shape: bandpass 'bpass.flt' centered at 3.5 Hz.
- 9.54.30 + 120 sec, BS TY inj ampl 5e.3
We tested again the control filter for BS TX tested last thursday. This time, it was possible to appreciate the effect of the filter (gain more at 200 mHz). GPS of the test:
- 10.36.00 + 120 sec, clean data with standard filter.
- 10.39.30 + 120 sec, test with new filter (txCorrAA2.flt).
We left the new filter as default. In Fig.s 1 is reported the measurement of the HF brench of the open loop of the BS TY, while in Fig.2 is plotted the spectra with the response of the new control filter for BS TX (red) with respect the current one (blue).
FInally, we tried to inject noise to the SSFS. The first thing we did was to comment the "define SSFS_FLT_NOISE" in order to be able to change the filters online, and then we restarted SSFS_phi, SSFS_noise and SSFS_Ctrl. We relocked and we started to try to make nosie injections. After some trials, we managed to inject noise around the UGF, and we already created a dedicated script that can be found: /virgoDev/Atomation/scripts/LSC/inject_ssfs.py. On Wednesday we would like to add two more dedicated noise injections at lower frequencies.
We will work on the script to produce the noise budget online.
An explanation for the spectral shape of the glitch is that it is a step function (which has a 1/F shape) applied to the mirror (which has a 1/F^2 response due to the pendulum), which makes in total a 1/F^3 shape.
Looking at the spectrum or at the time-frequency shape of the 25' glitches may give some hint about their origin.
The attached plot shows the spectrum of h(t) when one of those glitches occured.
The h(t) ASD is 3e-21 at 20 Hz and 3e-22 at 40 Hz.
It means that, when the glitch occurs, h(t), below 100 Hz, behaves like 1/f^3.33
I guess that a kink on the NE or WE marionnetta actuators would produce a 1/f^4 glitch in h(t)
And a kink on the NE or WE mirrors actuators would produce a 1/f^2 glitch in h(t).
Just a remark: the mystery noise is 1/f^0.66 and 3.33+0.66 = 4. But this is just numerology!
Has anyone a good explanation for the glitch spectrum shape 1/f^3.33 ?
An explanation for the spectral shape of the glitch is that it is a step function (which has a 1/F shape) applied to the mirror (which has a 1/F^2 response due to the pendulum), which makes in total a 1/F^3 shape.
Unless the ticks fool me, at 20 Hz the ASD is "a little more than" , and at 40 Hz something between and . This means a power-law exponent between
and "a little less than" .
At these frequencies, the glitch ASD could be affected by the noise background. We can move upward and repeat the estimate around the frequencies of the maximum intensity identified by omicron triggers, which is around 40 Hz. For example, from Didier's plot, the ASD is about at 30 Hz and at 70 Hz. This leads to a power-law exponent of -2.72.
This is somewhat midway between a step function, as explained by Michal, and an impulsive force, like a Dirac delta, whose response would have produced a power law with exponent -2. And, just looking at the math, an exponent of -2.5 could be the response of a "hyperbolic-step-function" of the form
...whatever may produce it.
The shift was dedicated to the planned ISC activity (control noise budget) carried out by Casanueva and Pinto.
Due to the activity, the ITF was unlocked several times and it was relocked by the ISC crew.
The ITF was left locked in LOW_NOISE_3 state.
Sub-system reportsCalibration
7:05 UTC - Daily calibration (CALIBRATED_DF_DAILY) successfully completed (end time 7:25 UTC).
DAQ
10:45 UTC - SSFS fastDAC flag red, signaling that a reconfiguration is required (FASTDAC_mezzanine_reconfiguration_required). Experts informed.
DET
7:40 UTC - B4 QD1 galvo soft guardian opened, vertically and horizontally, due to too large corrections. I restored its functioning by manually closing the B4 QD1 galvo loop at 8:20 UTC.
The BNS range has been slowly oscillating on daily time scale in recent days. The attached plot shows BNS range and Etalon temperature over time from March 3rd to this morning. BNS range seems to nicely follow the Etalon temperatures, in particular when NI and WI temperature oscillate in phase.
I've added the "INF_TCSroom_TE" channel to the previously shown data of the glitch period. Fig. 1 shows the most correlated temperature channels with the glitch period. The channels have been time shifted according to what Francesco extracted (https://logbook.virgo-gw.eu/virgo/?r=63479).
The shif of this new channel is around 7 h before the glitch period making it even earlier than "INF_NI_BOTTOM_TE1" by almost 3 h. Although, the correlation seems smaller compared to the "BOTTOM_TE1" channel.
Fig. 2 shows a close-up of these channels.
After restricting the CLEAN data to its first 80 s (txt file updated accordingly), a correct projection can be computed, and it is attached.
Looking at the kick during calibration found by Michal, it happens when stopping the injections of lines on NE and WE mirrors, see figures. The lines were properly stopped with a ramp on WE, but there is something weird happening on NE: a sudden stop of some lines at 7h03m14s, while some are properly decreasing with a ramp.
Looking at the logs of the injection script and of CALnoise, we must have found the source of this issue. In order to stop the injections, we reloaded the CALnoise configuration, and just after, without wait time, we also forced to apply the updated parameters (command cm_send(CALnoise, 'AcParamSet') ), while the reload of CALnoise already force the update. So the second command forced to apply the parameters during the on-going transition, and for some lines which were already being in transition, it resulted in a sudden amplitude set to 0.
The call of this second command has been commented in the file CALI_common.py in Metatron (function reset_CALnoise). This function was called at the end of every calibration injection. So, every time we stopped the calibration injections. such a kick may have happened, or not, depending on the exact time of the command sequence.
2024-03-16-07h04m13-UTC>INFO...-AcSineWaveChSet> line79 0V@0Hz(-9223372036854775808ns), time 1394607872, lDphi 0, phiT0: 0 - fType fast - offset 0 - rampTime 1s - line 0/98.7 2024-03-16-07h04m13-UTC>INFO...-AcEngStateSet> state 2(4) - nload 324/324(0) - nLoadFake 0 - cntLoad 44532024-03-16-07h04m13-UTC>INFO...-AcCompGpsLoadSet> GPS1394607872/0 - stsGps 12024-03-16-07h04m13-UTC>INFO...-AcRootParamSet> done at GPS1394607871 - with reset(1) - nLoad 0, nLoadApply 0, nApplyOnly 0 received from Cm - Load expected at GPS1394607872/1394607871+1 , rtn Ok - setTime 0.002751s2024-03-16-07h04m13-UTC>INFO...-AcCmParamSet> received from inject_checkHrecMir_script - cmd 0 - nApply 1 2024-03-16-07h04m13-UTC>WARNING-AcRootParamSet> GPS1394607871 - last Load GPS1394607872 wait completion- nLoad 0, nApply 0 received from Cm2024-03-16-07h04m14-UTC>INFO...-AcSineWaveChSet> line02 - previous ramp not complete remains 0.9949s2024-03-16-07h04m14-UTC>INFO...-AcSineWaveChSet> line02 0V@15.33Hz(65231572ns), time 1394607873, lDphi 0.00963212, phiT0: 0.565487300669226 - fType fast - offset 0 - rampTime 0s - line 15.33/18.2 2024-03-16-07h04m14-UTC>INFO...-AcSineWaveChSet> line03 - previous ramp not complete remains 0.9949s2024-03-16-07h04m14-UTC>INFO...-AcSineWaveChSet> line03 0V@23.33Hz(42863266ns), time 1394607873, lDphi 0.0146587, phiT0: 0.565471744535376 - fType fast - offset 0 - rampTime 0s - line 23.33/23.2
ITF Mode: LOCKED, AUTORELOCK_FAILSAFE engaged
ITF State: LOW_NOISE_3_SQZ
Quick Summary: IMC and RFC locked; all Suspension loops closed; all SBEs loops closed;
Activities ongoing: none.
In the following lock, lines and servos have been turned back on at 00:20:30 UTC.
In the following lock, lines and servos have been turned back on at 00:20:30 UTC.
We concluded the campaign of near field magnetic injections of elog 63540:
We performed the full set of environmental injections by using the ENV_MAIN node (ITF was in LOW NOISE 3 SQZ)
We tried to perform the "same" colored noise injections in CEB by using the "AcousticInjectionCEB" process in the VPM (pointing to the new executable /virgoApp/EnvSweepts/v2r1p1/... )
Conclusion: we need to test again the ENV_MAIN after these fixings. About 1 hour is needed.
The shift was dedicated to the planned ENV Activity, magnetic and acoustic injections, carried out by Tringali and Fiori.
Upon reaching the site I found the ITF in LOW_NOISE_3_SQZ, it unlocked at 9:50 UTC and 11:12 UTC due the the human activity around the NE Suspensions. It was possible to relock the ITF after few attempts.
Activity still in progress, ITF left locked.
"NE mysterious noise"
One additional event occurred March 16 at 22:23 UTC and caused an unlock: Figure 1 (trend), Figure 2 and Figure 3 (spectrogram of accelerometers). The frequency of the turbo pump line (547Hz) did not seem to be affected at all (Figure 4).
At that time, according to Antonio's and Fabio's reports: the main turbo pump was switched off and the spare turbo pump was on, the accelerometer named ENV_NE_BOTTOM_ACC was placed on the main turbo (see picture in Figure 5).
Figure 6 compares the spectrum of this accelerometer (orange) with similar accelerometers on the NE big flange (blue) and on the NE cryo trap (green). The signal seen by the accelerometer on the main pump indeed detected a large signal.
We moved the accelerometer named ENV_NE_MIDDLE_ACC on top of the spare turbo pump. See picture in Figure 7.
We switched off the external cooling fan of the main turbo.
Extra glitches in accelerometer ENV_NE_ACC_Z: in Figure 2, we notice several fast glitches which are not seen by the other accelerometer. Need further investigation.
ITF Mode: LOCKED, AUTORELOCK_FAILSAFE engaged
ITF State: LOW_NOISE_3_SQZ
Quick Summary: IMC and RFC locked; all Suspension loops closed; all SBEs loops closed; B5 QD1 glavo open since 23:57 UTC.
Activities ongoing since this morning: No activities ongoing.
At the beginning of the afternoon we had some problem with the lock due to a series glitches at the NE tower (see plot); so I went to the north end building and stayed there for a while to hear "in person" some of these events, I caught two of them, they clearly came from the big vacuum turbo pump mounted on the north side of the tower, while I was there I moved the pzt accelerometer from the tower base to the top of the vacuum valve in front of the turbo pump; in the meantime the ITF relocked up to LOW_NOISE_3 and the work on laser phase noise injection restarted, the ITF unlocked at 18:15UTC again because of the NE so I called Antonio to switch off the pump; ITF relocked in LOW_NOISE_3 at 19:48UTC; unlocked at 20:40UTC, this time because of the PR suspension? (2nd plot).
I left the ITF locked in LOW_NOISE_3_SQZ state with the failsafe engaged.
Calibration
- 20:06UTC: start injection PCAL high frequency lines.
SBE
at 18:27UTC the SNEB position loop was opened by the guardian, controls properly closed.