Reports of 57916
Detector Operation (Operations Report)
berni - 16:00 Monday 04 March 2024 (63480) Print this report
Operator Report - Morning shift

This morning I found the ITF down with the RFC not able to relock; I contacted the INJ on-call.

At around 8:30 UTC Piernicola was on site and he was able to fix the problem; the problen occurred at around 5:37 UTC after an unlock when Fmoderr moved the MC FO Z in the wrong direction.

The ITF was then relocked in LN3 at the first attempt (10:14 UTC); the planned ISC started from this point.

 

TCS

At 7:00 UTC the WI chiller stopped to work; the backup chiller was properly put in operation by the "guardian". With Nicola we went in TCS room we reamerd the WI chiller and putting in loop the backup chiller. The WI CO2 laser was not affected by this misbehaviour.

 

HVAC

An external firm fixed the problem at the ACS COB.

 

Images attached to this report
AdV-ISC (Commissioning up to first full interferometer lock)
mantovani - 15:57 Monday 04 March 2024 (63481) Print this report
SR ty set point and SRCL set point scans

This morning I've done a very slow scan of SR ty set point, see figure 1. I found the best value in terms of sensitivity to be 160Hz (I could try to go lower).

While for the SRCL set point, figure 2 and 3, it is visible that as soon as I add an offset the CMRF (both low and high frequency) increase spoiling the sensitivity. At very low SRCL set Hrec started to become crazy. Moreover it is visible that the largest OG LF is at the standard SRCL set point.

All these scans have been done very slow to let all the other loops to follow.

Figure 4 is the trend of all the tests.

Images attached to this report
AdV-SAT (Suspension control upgrade)
Boschi - 15:57 Monday 04 March 2024 (63482) Print this report
Comment to Fan speed level of Sc_NI crate (63457)

At 13:10 UTC Sc_NI fan speed level has been reverted back to 5 while Sa_NI has been increased to 15, for noise hunting purposes.

AdV-ISC (Steady state longitudinal control conceptual design)
mwas - 14:59 Monday 04 March 2024 (63478) Print this report
SSFS noise coupling and arm asymmetric length

The west arm has been measured to be ~3cm shorter than the north arm (VIR-1085A-21). This causes the 56MHz TEM00 to resonate at different frequencies in the north and west arm. A question is if it causes issues with noise couplings.

Figure 1 shows the fitted coupling of CARM to DARM at a time of good sensitivity.

Figure 2 is the corresponding noise budget.

A 3cm length asymmetry over 3km length arm creates a 1e-5 coupling of CARM to DARM. This makes sense intuitively, and is confirmed by optickle simulations. So that asymmetry is comparable to what is measured once BS and SR are misaligned in LN3. Before misalignments the measured CARM to DARM coupling can easily be a factor 10 higher.

So the ~3cm arm length difference is not a major contribution to SSFS noise coupling. The other simple noise coupling is due to the BS AR coating, which creates a 3e-6 CARM to DARM coupling, the two could cancel each other if the west arm was ~1cm longer than the north arm. Something to keep in mind for the far future that we could use the difference in arm length to fine tune CARM to DARM couplings if we ever get to a situation where the coupling starts to be smaller than 1e-5.

Images attached to this report
AdV-ISC (Commissioning up to first full interferometer lock)
mantovani - 8:33 Monday 04 March 2024 (63477) Print this report
MICH2DARM and SRCL2DARM couplings during SR misalignment @ LN2

Now the MICH SRCL and PRCL lines are on in the misalignemnt phase of the SR in LN2 (in order to spot variation of alpha and more in general for the couplings).

In figure 1 the MICH2DARM and SRCL2DARM couplings are shown in function of the DCP frequency. It can be seen that MICH varies its coupling while SRCL (apart from a change in the coupling, which could be due to the new controller, to be checked when it has been loaded) is quite constant.

It should be worth, at the end of the thermal tuinings, to re-check alpha in the final position of SR.

Images attached to this report
AdV-ISC (Commissioning up to first full interferometer lock)
mantovani - 8:25 Monday 04 March 2024 (63476) Print this report
Glitch rate vs NI RH and NI Bottom TE

As it has been observerd in the past the NI tower temperature can drive the glitch rate. In order to better localize the source of the glitch I've tried to measure the delay between the two probes that seems to be more correlated with the glitch rate and the glitch itself.

In figure 1 and 2 the NI RH te and NI Bottom TE are shown. It is visible that the change of temperature of the RH is delayed wrt the glitch rate behavior of about 270mins while the bottom TE influences the glitches with a delay of 270mins. All these values are indicative and found minimizing the R of the superposition between  the two curves.

It is not clear at all if this can help in the localization.

Images attached to this report
Detector Operation (Operations Report)
berni - 8:19 Monday 04 March 2024 (63475) Print this report
Operator Report - initial report

ITF Mode: LOCKING (Autorelock Failsafe engaged);
Quick Summary: RFC not locking; all Suspensions Loops closed; all SBE Loops Closed; WI TCS chiller down;
Activities ongoing since this morning: None

Images attached to this report
AdV-TCS (Ring Heater)
nardecchia, spinicelli, menzione, sorrentino - 23:07 Sunday 03 March 2024 (63474) Print this report
Locking issues-not solved

During the afternoon, the ITF unlocked sistematically trying to lock the OMC. The fringe appeared too bright [0.22-0.28 mW].

At 17.16 UTC, the SR RH power has been settled at 23.13 V (P=7 W) form 6.6 W.

During the SR RH thermal transient, we tried to decrease B1p by acting on the DAS. 

The effects on the fringe were vey poor, thus at the end of the shift, we reset the DAS powers at the nominal ones.

Images attached to this report
Detector Operation (Operations Report)
menzione - 22:59 Sunday 03 March 2024 (63473) Print this report
Operator Report - Afternoon shift

Upon arrival I found ITF locked at LN3.
Under request of Spinicelli and Nardecchia, at 14:57 UTC, we unlocked and tried to relock ITF, but unfortunately the bad weather conditions prevented a stable lock. Including an earthquake with Mag 6.4 occurred in Australia (fig. 1)
During one of the unlock, SDB1 moved from it's usual position. At 15:06 UTC I had to fixed setpoint and recovered the floating setpoint at CARM_MC_IR. In the same lock acquisition the galvo of B1pQD1 remained opened, I open/closed it via VPM.

According with the crew, we left ITF in CARM_NULL_1F (AUTORELOCK_FAILSAFE) after the usual cross-alignments in ACQUIRE_DRMI.

Parallel activity:
Firewall hardware upgrade by Computing team concluded at 17:30 UTC. 

Sub-system reports

DAQ
18:13 UTC - SPRB_MotSwitch and SIB2_MotSwitch VPM process crashed. Properly restarted via VPM.

Images attached to this report
Detector Operation (Operations Report)
mwas - 18:47 Sunday 03 March 2024 (63472) Print this report
Comment to Operator Report - Morning shift (63471)

Figure 1 shows a simple analysis of the arm scan done with cold arms this morning. The marke shows the position of the 56MHz TEM00 in the north and west arms. There is a carrier HOM in between the two. When the interferometer gets hot the carrier HOM should move by ~0.005 of an FSR towards the right, the HOM in the north arm will then get close to the 56MHz TEM00, but still above it. There is not much room for tuning the EM RH in this position, increasing the correction will make the carrier HOM interfer with the 56MHz in the cold west arm, while decreasing the EM RH correction will make the carrier HOM interfer with the 56MHz in the hot north arm.

/users/mwas/TCS/analyzeFSR_20240303/analyzeFSR.m

Images attached to this comment
Detector Operation (Operations Report)
amagazzu - 15:57 Sunday 03 March 2024 (63471) Print this report
Operator Report - Morning shift

Upon reaching the site I found the ITF in LOCKING_ARMS_BEAT_DRMI_1F, I went back in LOCKED_ARMS_BEATING and, from 7:09 UTC to 7:39 UTC, performed a FSR Scan (function CARM_SET_scan_FSR(15)). After this set of measurements was completed I started to relock the ITF and, after two attempts, it was possible to reach LOW_NOISE_3 at 9:52 UTC, but the lock lasted only until 10:01 UTC. It was possible to reach LOW_NOISE_3 again at 11:20 UTC, but the lock lasted only until 11:27 UTC. 
For the following attempts, we left the ITF in LOW_NOISE_2 from 12:28 UTC to 13:42 UTC, also while locking Spinicelli updated the DARM gain.
ITF left locked.

No DMS alerts were received during the shift.

Other activities carried out during the shift
- Cascina firewall hardware upgrade (Cortese, Kraja), still in progress

Sub-system reports

DAQ
- USGS found crashed and stopped working at 10:24 UTC. Process restarted via VPM;
- DMSserver crashed at around 11:41 UTC. Process restarted via VPM at 11:47 UTC.

Comments to this report:
mwas - 18:47 Sunday 03 March 2024 (63472) Print this report

Figure 1 shows a simple analysis of the arm scan done with cold arms this morning. The marke shows the position of the 56MHz TEM00 in the north and west arms. There is a carrier HOM in between the two. When the interferometer gets hot the carrier HOM should move by ~0.005 of an FSR towards the right, the HOM in the north arm will then get close to the 56MHz TEM00, but still above it. There is not much room for tuning the EM RH in this position, increasing the correction will make the carrier HOM interfer with the 56MHz in the cold west arm, while decreasing the EM RH correction will make the carrier HOM interfer with the 56MHz in the hot north arm.

/users/mwas/TCS/analyzeFSR_20240303/analyzeFSR.m

Images attached to this comment
AdV-COM (1/√f noise)
mwas - 10:31 Sunday 03 March 2024 (63470) Print this report
Comment to Polarization measurements with B5 (63347)

As discussed in VIR-0200A-24, the beam splitter amplifies the angle measurement of polarization noise by a factor sqrt(40) instead of 40. As the polarization angle is between electromagnetic fields and not powers. Hence the upper limit on polarization noise in LN3 are actualy  ~8e-10 rad/rtHz.

Detector Operation (Operations Report)
amagazzu - 8:13 Sunday 03 March 2024 (63469) Print this report
Operator Report - Initial Status

ITF Mode: LOCKING (Autorelock Failsafe engaged);
ITF Lock_State: LOCKING_ARMS_BEAT_DRMI_1F;
Quick Summary: ISYS in standard state; All Suspensions Loops closed; All SBE Loops Closed; COB Farm temperature fluctuating (expert informed of the issue);
Activities ongoing since this morning: FSR Scans

Images attached to this report
AdV-TCS (Ring Heater)
nardecchia, spinicelli, magazzu, menzione - 23:30 Saturday 02 March 2024 (63468) Print this report
Lock acquisition vs SR RH tuning

This morning several lock issues have been experienced.The ITF is always unlocked in one of the steps: acquire LN1-LN1-acquire LN2.

After some checks performed by Piernicola and some trials to adjust the NI DAS outer ring power without succeeding,  at 14.30 UTC, the SR RH power has been increased up to 7 W (23.13 V). At this point, we know that ITF is workable.

Finally, at 16.27 UTC, the ITF reached LN3 (Piernicola adjusted the DARM gain). 

The maximum BNS range reached ~ 2 hrs after increasing the SR RH power, suggesting a better WP at a slightly higher power than 7W (the curvature induced by the RH has an overshoot). Thus, at 18.32 UTC, SR RH power has been increased up to 7.2 W (23.46 V) to investigate this hypothesis. 

To test the lock acquisition, the ITF has been manually unlocked at 20.48 UTC

Than, we were not able to relock ( the ITF unlocked during the OMC lock).

The ETM RH scan has been postponed.

Images attached to this report
Detector Operation (Operations Report)
menzione - 23:00 Saturday 02 March 2024 (63466) Print this report
Operator Report - Afternoon shift

Upon arrival I found ITF relocking and Spinicelli still investigating about the unstability of the lock.
We reached a stable LN3 only at 16:28 UTC. Then ITF kept the lock for the whole shift an the planned TCS on  ETM RH tuning went on without major problems with Nardecchia from remote.
According with Sorrentino and Nardecchia we decided to postpone the FSR and arms scans.

Under request of Nardecchia at 20:48 UTC we unlocked manually and relock. 

ITF left in AUTORELOCK_FAILSAFE.

No particular operations to report.

Images attached to this report
Detector Operation (Operations Report)
amagazzu - 16:02 Saturday 02 March 2024 (63465) Print this report
Operator Report - Morning shift

Upon reaching the site I found the ITF relocking. I started the planned weekly calibration from DOWN State, here the timetable of the actions performed.

7:01 UTC - Measurement of the TF between CAL and Sc channels (CALIBRATED_DELAY);
7:09 UTC - Measurement of actuators response for PR and BS mirrors (CALIBRATED_PRWI);
8:00 UTC - Measurement of actuators response for SR mirror (CALIBRATED_SRNI);

I attempted to relock to perform the rest of the calibrations, but the ITF systematically unlocked while reaching LOW_NOISE_1. Spinicelli and Nardecchia started to investigate the issues, relock in progress. 

Sub-system reports

DET
At around 14:40 UTC, while the ITF was in CARM_NULL_1F, B1p QD1 galvo was opened (float corrections). At 14:48 UTC, from VPM using the process SDB2_Quadrants, I opened and closed the loop.

Oncall events

ISC
(02-03-2024 10:50 - ) From remote
Status: On-going
Description: The ITF kept unlocking while at LOW_NOISE_1, with the locks lasting only few minutes.
Actions undertaken: I contacted the ISC oncall (Spinicelli) who, from remote, attempted to relock the ITF.

Images attached to this report
Detector Operation (Operations Report)
amagazzu - 8:14 Saturday 02 March 2024 (63464) Print this report
Operator Report - Initial Status

ITF Mode: LOCKING (Autorelock Failsafe engaged)
ITF Lock_State: LOCKING_ARMS_IR
Quick Summary: ISYS in standard state; All Suspensions Loops closed; All SBE Loops Closed; COB Farm temperature fluctuating (expert informed of the issue);
Activities ongoing since this morning: Weekly Calibrations

Images attached to this report
AdV-TCS (Ring Heater)
nardecchia, gherardini, sorrentino - 23:35 Friday 01 March 2024 (63462) Print this report
SR RH tuning- afternoon

This afternoon, we checked the effect of the SR RH power decrease (63456).

The ITF locked in LN3 at 15.50 UTC and unlocked at 17.06 UTC.

The ITF relocked at LN2 at 17.40 UTC but it has been manually unlocked at 18.11 UTC because of an earthquake compromising the lock.

The ITF relocked at LN2 at 19.47 UTC. We left the ITF in this state for approximately 30 minutes to observe the behavior of the DCP before proceeding to LN3.
During this lock, I also tried to investigate some changes of NI DAS powers to improve the CD but the results were confusing and, despite this, we never reached the BNS range of this night lock.

So, discussing also with Fiodor, at 22.13 UTC, in LN3, we settled 6 W (21.41 V) on the SR RH, which is halfway between 5 W and 7 W.

The main ITF signals since yesterday morning are shown in the attached figure.

 

Images attached to this report
Detector Operation (Operations Report)
gherardini - 23:05 Friday 01 March 2024 (63463) Print this report
Operator Report - Afternoon shift

The TCS tuning went on in the afternoon; after the decreasing of SR ring heater power done at the end of the morning shift and waiting about two hour of thermalization the ITF was locked up to LOW_NOISE_3 without problems, Ilaria worked on the DASs tuning for the rest of the shift, the work is still in progress, I left the ITF locked in LOW_NOISE_3 with the failsafe engaged.

Sub-system reports

SBE
at 14:52UTC the SNEB position loop was opened by the guardian, controls properly closed.

Images attached to this report
AdV-COM (automation)
bersanetti - 22:06 Friday 01 March 2024 (63461) Print this report
New channel: DQ_META_ITF_LN3_NOMINAL

As a result of the SR alignment scheme in LOW_NOISE_3 (see #63386), I added a new channel, named DQ_META_ITF_LN3_NOMINAL, which is pushed to the DAQ by the ITF_LOCK node. It can have three values:

  • -1: the interferometer is not in LOW_NOISE_3;
  •  0: the interferometer has entered the LOW_NOISE_3 state; at this point SR is still aligned and the DRMI lines are still on; the alignment scheme of SR is changed;
  •  1: SR has finished being misaligned (target DCP has been reached), and the DRMI lines are turned off; this is the steady state intended for LOW_NOISE_3.

The channel is available since today at 18:14:31 UTC.

AdV-NNC (NEB)
Allocca - 19:46 Friday 01 March 2024 (63459) Print this report
Tiltmeter characterization and sensitivity

The tiltmeter transfer function has been measured by injecting noise on both the actuators couple, in order to verify that the response doesn't change from one couple to the other.

ACT2 = 2V --> GPS = 1393261900; D = 1200;

ACT2 = 0V --> GPS = 1393001500; D = 600;

In figure 1 the OLTF resulting from the two noise injections with the model superimposed.

In a quiet period the OL sensitivity of the tiltmeter has been measured (figure 2) and, dividing by (plant-1) the ground tilt is derived (red trace). Its ASD results to be about 2.5 nrad/sqrt(Hz) at 100 mHz, and is of the order of 1e-10 rad/sqrt(Hz) and below in the frequency band 1-20 Hz. This is compatible with what has been measured in the past months (figure 3), when the resonance frequency of the system was 23 mHz instead of 7 mHz.

What was noticed by Paolo is that, for a particular perturbation (maybe a nearby truck) the signal as read by the tiltmeter @2.6Hz has the same amplitude as read by the Optical Lever (figure 4).

Further analysis ongoing.

Images attached to this report
AdV-SAT (Suspension control upgrade)
Paoletti, Boschi - 17:20 Friday 01 March 2024 (63458) Print this report
Comment to Fan speed level of Sc_NI crate (63457)

Having a look at the microphones, we see that there was a first speed increase of +10% at 14:11:00 UTC (from 270 Hz to 300 Hz) when the control was set from "5" to "10."

Then another +10% (from 300 Hz to 330 Hz) at 15:40:00 UTC due to a further speed increase from "10" to "15."

The best witness is ENV_EQB2_MIC

AdV-SAT (Suspension control upgrade)
Boschi, Paoletti - 16:05 Friday 01 March 2024 (63457) Print this report
Fan speed level of Sc_NI crate

At 15:15 LT fan speed level of Sc_NI crate has been increased from 5 to 10 to investigate the 25-min-glitches. It will be reverted to previous value after the weekend.

Comments to this report:
Paoletti, Boschi - 17:20 Friday 01 March 2024 (63458) Print this report

Having a look at the microphones, we see that there was a first speed increase of +10% at 14:11:00 UTC (from 270 Hz to 300 Hz) when the control was set from "5" to "10."

Then another +10% (from 300 Hz to 330 Hz) at 15:40:00 UTC due to a further speed increase from "10" to "15."

The best witness is ENV_EQB2_MIC

Boschi - 15:57 Monday 04 March 2024 (63482) Print this report

At 13:10 UTC Sc_NI fan speed level has been reverted back to 5 while Sa_NI has been increased to 15, for noise hunting purposes.

Detector Operation (Operations Report)
menzione - 15:57 Friday 01 March 2024 (63455) Print this report
Operator Report - Morning shift

Upon arrival I found ITF LOCKED on IR.
I recovered the lock up to LN2.
The planned TCS/ISC activity on thermal tuning for optical gain, DCP, and CMRF (Mantovani, Palma, Taranto) started at 07:30 UTC and went on without problems only till the unlock of 09:36 UTC.
The lock was very unstable so I contacted DET expert who is still investigaring of the unlocks at DC_READOUT. 

 

Sub-system reports

DAQ
14:15 UTC - USGS process crashed / restarted via VPM.

Oncall events

DET
(01-03-2024 13:30 - 01-03-2024 ) From remote
Status: On-going
Description: unlocks at DC_READOUT

Images attached to this report
AdV-TCS (Ring Heater)
mantovani, palma, taranto, menzione - 15:48 Friday 01 March 2024 (63456) Print this report
SR RH tuning

The goal of the shift was to tune the SR RH by increasing its power and monitoring the DCP.

Last night there was a successful LN3 (started at 21.03 UTC) which confirmed the ITF’s workability, after the step back of the ETM RHs’ powers (63445), in the TCS configuration which is summarized in the two following tables.

CO2 powers:

 

Reference

CH [W]

INNER DAS [W]

OUTER DAS [W]

W

on the ITF

0.047

0

1.27

on the pickoff 

0.291

0

0.208

N

on the ITF

0.116

0.340

3.68

on the pickoff 

0.715

0.055

0.60

 

RHs powers:

NE RH [W]

WE RH [W]

SR RH [W]

4.7

6.3

7

 

 

 

 

The cavities’ power remained stable at approximately 485 mW, with the sidebands showing an increasing trend, particularly the 56 MHz. Meanwhile, the contrast defect was decreasing and the BNS range was oscillating around 54 Mpc. The USB and LSB of 56 MHz on B4 were still separated, albeit to a lesser extent than in previous locks. The main ITF signals of this lock are shown in Fig. 1.

After that lock, there were various unlocks due to the high gain of the DIFFp TY. Consequently, this morning Maddalena reduced the gain by 50%.

At 8.44 UTC ITF locked at LN2.

At 09.15 UTC: SR RH increase up to 9 W (26.23 V)

At 9.37 UTC: ITF unlocked and it was difficult to relock again. There were several unlocks before reaching DC READOUT, as already happened on Sunday (63398).

In agreement with the commissioning coordinator, the idea was to decrease the SR RH power in order to scan a different WP in the opposite direction, since the ITF did't work properly after the power increase up to 9 W.  At 13.50 UTC we manually unlocked the ITF in order to start the Fast Response for the SR RH.

Thus, at 13.51 UTC we decreased the SR RH power from 9 W (26.23 V) to 4 W (17.48 V).

The effect of this action will be evaluated in the afternoon shift.

Images attached to this report
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