Reports of 40821
AdV-AEI Squeezer Integration (General)
vardaro - 0:09 Friday 22 March 2019 (45344) Print this report
Squeezer Phase scan and tuning

I performed a phase scan to investigate the sqz and asqz level after the tuning of the ITF (log file attached)

The measured squeezing level in DARM and in HREC is about -3dB whereas the measured asqz level is about 5.6dB (black lines in fig1)

The maximum squeezing level correspond to a CC phase of 0.6 rad, whereas the minimum of the mag is 0.9 rad.

I left the squeezer with these phase parameters and the AA dither line amplitude equal to 0.007. After the tuning the ITF unlocked. After the relock the squeezing level was 3dB see attached plot

Images attached to this report
Non-image files attached to this report
Virgo Runs (ER14)
berni - 22:57 Thursday 21 March 2019 (45343) Print this report
operator report - afternoon shift
The whole shift was dedicated to ITF tuning; the ITF kept the lock for all the shift.

Nothing else to report.

DetChar
STATE_VECTOR - DQ_VetoThr_VETO_RATE_SNR5_OVERFLOW grey flag; experts informed.

Pending
Calibration: run CALIBRATED_MIRTOMAR before switching to Science mode.
AdV-COM (AdV commissioning (1st part) )
nardecchia, allocca, bersanetti, casuaneva, chiummo, fafone, mantovani, rocchi, ruggi, tacca, vardaro - 22:46 Thursday 21 March 2019 (45340) Print this report
Working point tuning - Back to 50 Mpc
As described in the entry # 45333, yesterday afternoon/night we performed the first steps for the tuning of ITF.
In order to have the referente for the maximum power of the sidebands we switched off TCS (20.01 UTC) and locked the ITF in SSFS state to allow the cooling down of the ITF.
After half an hour we locked in LN3 and the maximum value measured by SPRB_B4_112_MHz_mag was 0.008 mW.
The ITF unlocked quickly due to a bad alignment. Then he locked again after the tuning of the alingment parameters performed by Diego, Paolo and Annalisa.
The sidebands started to degrade, so we turned on the DAS with the following values:
1) 21.50 UTC-> NI IN: 350 mW WI IN:70 mW
NI OUT: 700 W WI OUT:140 mW

The sidebands started immediately to increase and settled around 0.066 mW.

At this point we changed the power applied on both DASes focusing on the increase of sideband and to minimize B1p without considering the very bad CMRF.
So:
1) 23.53 UTC-> NI IN: 350 mW WI IN:120 mW
NI OUT: 700 W WI OUT:240 mW

-> no big effects observed in B1p and sidebands. Bad CMRF.

2) 00.23 UTC-> NI IN: 350 mW WI IN:0 mW
NI OUT: 700 W WI OUT:0 mW

-> disaster, everything spoiled.


3) 00.42 UTC-> NI IN: 350 mW WI IN:120 mW
NI OUT: 1.4 W WI OUT:240 mW

-> good point for the night (BNS range 48 Mpc with squeezing). But bad CMRF.

Paolo, Diego and Annalisa tuned the alignment during all steps.
During the night the ITF had a bad behaviour due to the BS alignment loop left open accidentally.

All signals during the steps are visibile in Fig. 1.

=========================================================================================
During the morning Julia, Maddalena and John worked on the comparison between the DF and CMRF (#45337).

Then we continued the activity started yesterday on the tuning of the ITF with TCS.
We changed the power applied on both DASes:

1) 10.29 UTC-> NI IN: 500 mW WI IN:120 mW
NI OUT: 1.4 W WI OUT:240 mW

-> no big effects observed in B1p and B4. Bad CMRF.

2) 11.56 UTC-> NI IN: 500 mW WI IN:120 mW
NI OUT: 1 W WI OUT:240 mW

-> no big effects observed in B1p and sidebands. Bad CMRF.

3) 14.29 UTC-> NI IN: 500 mW WI IN:120 mW
NI OUT: 1.7 W WI OUT:240 mW

-> B1p and 56 MHz signal improved. Bad CMRF.

4) 15.38 UTC-> NI IN: 500 mW WI IN:120 mW
NI OUT: 1.7 W WI OUT:120 mW

-> 56 MHz increased, B1p improved. BNS range 49 Mpc with no squeezing. Bad CMRF.

5) 17.06 UTC-> NI IN: 600 mW WI IN:120 mW
NI OUT: 2.04 W WI OUT:0 mW
-> This last step has been performed to apply a differential effect in order to improve the CMRF.
Good effect on the CMRF without spoiling the dark fringe.
The range reached 50Mpc but the CMRF was not so good as Feb. 5th (55Mpc).
So we performed another step to minimize the CMRF:
6) 17.06 UTC-> NI IN: 600 mW WI IN:120 mW
NI OUT: 2.5 W WI OUT:0 mW

-> Good CMRF and B1p but decrease of 56 MHz sideband.
So we decided to come back a bit by applying:
7) 17.06 UTC-> NI IN: 600 mW WI IN:120 mW
NI OUT: 2.25 W WI OUT:0 mW

-> Good CMRF, good B1p and good 56 MHz sideband power!

All signals during the steps are visibile in Fig. 2.
Julia tuned the alignment working point and we left the ITF in this configuration.
The comparison of sensitivity curves among Feb 5th, yesterday night after the tuning and today at the end of the work is in fig. 3.
Images attached to this report
AdV-AEI Squeezer Integration (General)
vardaro - 21:58 Thursday 21 March 2019 (45342) Print this report
Comment to Squeezer working point (45325)

Phase scan (figure 1)

  • squeezing level -2.4 dB, antisqueezing level 5.3 dB.
  • Red line Darm 1350-1750 Hz, Blue Line: Darm 2600-2800 Hz, Yellow Line Hrec 2600-2800 Hz, Violet line Hrec 1350-1750 Hz, Green 2650-314 0Hz 
  • The green line is a BRMS computed with window of 1s whereas the other BRMSs are computed with 20s windows
  • The phase scan in DARM is less visible than in HREC: this was due to the bad CMRF of the ITF, so we had a lot of frequency noise
  • The phase noise was performed in a not good alignment condition so the maximum squeezing level was 2.4 dB
  • This is visible observing the B1_PD1_mag 3.0e-3V when was misaligned and 3.5e-3 V when I realigned it exploting the dither loop
  • The brms channel computed with 1 s windows is faster than the other, so it allow to computed better the phase distance between mag and sqz (0.33 rad)

Night Injection (figure 2)

  • The night injection, after the realignment started with -2.8 dB of squezzing in the bandwidth between 2650-3140Hz
  • After 6 hours the sqz level was decreased to -2.2 dB, but this was probably due to a 56MHz RIN, see B1s2 DC photodiode (second line of the plot)
  • After the locking seems that for long time we injected antisqueezing, but this can be due to hrec not updated or a bad working point of the itf. The phase error signal of the slow CC loop was in a good position and not drifted (third line)

Coherent control phase noise (figure 3)

I performed the CC phase noise calibration with two different methods

Method 1:

  1.  open shutter, CC open,
  2. Measure the Aplitude of the fringes and from them obtaining the V/rad
  3.  PD1cal =  0.00399 V/rad,   PD2cal =  0.10984 V/rad

Method 2:

  1.  Open shutter, Close CC,
  2.  perform a phase scan
  3.  plot SQZ_B1_PD{1,2}_Q as a function of the CC phase,
  4.  fit the linear part of the curve 
  5.  PD1cal =  0.00388 V/rad,  PD2cal =  0.11375 V/rad

The two methods are consistent. I computed the rms phase noise of the CC between 0.05Hz and 25 kHz and I obtained 20 mrad in loop (PD1) and 23 mrad out of loop (PD2).

Images attached to this comment
Interesting data (Interesting data)
fiori, dandrea, soldani, paoletti - 17:25 Thursday 21 March 2019 (45339) Print this report
Comment to CEB Ghost all nights (45261)

Massimo and Davide ideed found the timer that was responsible of the daily 1s switch off of the CEB hall air conditioner. After an attempt to reprogram it which failed (the conditioner continued with the periodic switch off) today the timerhas been electrically bypassed.

Environmental Monitoring (Environmental Monitoring)
fiori, paoletti - 16:47 Thursday 21 March 2019 (45338) Print this report
Comment to EIB and LB microphones OFF because of failure of conditioning unit (45318)

The problem was in the power adaptor that broke. ELE team replaced it. Now the system is back in operation. The ENV_LB_MIC and ENV_EIB_MIC channels can be unshelved in DMS.

AdV-ISC (Alignment design requirements)
mantovani, casanueva, brooks - 15:01 Thursday 21 March 2019 (45337) Print this report
Comparing minimum CMRF and minimum B1p power BS operating points

This morning (March 21 0730UTC) the BS loop was found open (as it was highlighted by the logbook entry from the nigth before, 45333). The BS_TX and TY were put in a configuration for minimum B1p.

Then we wanted to compare the two configurations: Low B1p and low CMRF.

Thus a sweep was conducted to determine the best working point for the BS TX and TY in terms of CMRF.

In a well functioning ITF the two working points should coincide. However, these two metrics were inversely proptional with the position of BS_TX and TY. Two set points were determined for each requirement. At each setpoint, the position of DIFFp TX TY and PR TX TY were tuned for minimum power on B1p and maximum power on B4_2f (also B5) respectively.

  1. Minimum CMRF: BS_TX: -0.013 BS_TY : -0.006
  2. Minimum B1p power: BS_TX: -0.017 BS_TY : 0.005

The attached plot (190321_BS_TY.png) shows a the behavior of the CMRF, B1p, and B4_2f  through a scan of BS_TY at a gps of 1237189790 for 30 minutes. It is shown that for the minimum CMRF the setpoint of BS_TY should be around -0.006, althought B1p power is at a maximum for this angle. Conversely, the minimum B1p power is for BS_TY > 0.002 and the CMRF is steadily increasing in this region.

The second plot is compares the two set points. The blue line is the low CMRF working point and the purple line is the low B1p working point. For the low CMRF, there is a lower difference between HrecClean and Hrec, 0.5 Mpc, which means low 56MHz RIN coupling. The low B1p shows 2 Mpc of difference. There is negligible difference in the B5 56 sidebands power between the two setpoints. The B4 sidebands are slightly lower for low CMRF. The structures from the detection are visible in the low CMRF Hrec, meaning that diffuse light is visible on the detection bench (which means not optimal alignment). Moreover, on the low CMRF working point the alighnment is less stable as shown by a larger fluctuation of power on the dark fringe.

To conclude, the low B1p point is more stable and robust. But it spoils the squeezing injection effect (high frequency noise). The low CMRF is not a stable working point.

Images attached to this report
Virgo Runs (ER14)
Nenci - 14:58 Thursday 21 March 2019 (45336) Print this report
Operator Report - Morning Shift

This morning I found the ITF locked in Science Mode, the activity scheduled (ISC) started without troubles.

7:46 UTC - Commissioning Mode activated.

13:58 UTC - ITF left locked in LowNoise3. All the subsystems worked properly, no particular problems or events to report.

Virgo Runs (ER14)
Sposito - 11:09 Thursday 21 March 2019 (45335) Print this report
Comment to Operator Report - Afternoon Shift 18 March 2019 (45298)

Some details of the INF interventions:

On 18th March, I went in the Cleaning Lab (where is the tank of the ultrapure water) to check the leak of water reported by M. Perciballi. Once there I contacted D. Soldani for instructions. He instructed me to close all 5 valves in order to stop the leak. ~ 19.30 UTC I did it.

Images attached to this comment
Virgo Runs (ER14)
Gherardini - 6:55 Thursday 21 March 2019 (44420) Print this report
Operator report - night shift 20/1
The afternoon activity on ITF and TCS tuning went on in the first part of the night, stopped at ~2:30UTC; the ITF unlocked just after few minutes of science because of the MC local control issue (1st plot), after the relock the ITF behaved very bad with powers unstable, very bad sensitivity and a clear misalignment visible on B1p camera (2nd plot), so at some point I decided to manual unlock and relock to see what happened; also this lock is not good with the same behaviour.

- guard tour (UTC)
3:35 --> 4:10
5:10 --> 5:45
Images attached to this report
AdV-COM (AdV commissioning (1st part) )
bersanetti, vardaro, ruggi, tacca, valentini - 4:16 Thursday 21 March 2019 (45334) Print this report
WE Violin Modes excited

Following today's (Mar 20th) activities on the WE suspension, we could not relock OMC2; looking at the DARM spectrum I found out that the violin modes of the WE payload were quite excited, making B1 to saturate. We tried then to damp them with the already used mechanism and GUI interface:

  • this is the first time we did that after the DSP->Acl migration of the ASC code, which reshuffled also the channels related to this issue;
  • the GUI in the user menu is out of date for the same reason; we checked out and used the updated version from SVN, which we should also push in /virgoApp as soon as possible;
  • we managed to lock up until LOCKED_OMC1_B1s2_DC, where we did the damping;
  • we did not do an extensive campaign to damp everything, but just the main offenders (2, 4 and 6, see Figure); 4 and 6 damped quite quickly (at least to reasonable levels) with standard filters, low gains and actuating on TX; unfortunately we did not manage to damp mode 2, with either of the two filters, either sign of the gain and trying also to actuate on TX or Y degrees of freedom;
  • after this, although the modes were still quite high, we managed to relock in LOW_NOISE_3 and started the work on TCS.
Images attached to this report
AdV-COM (AdV commissioning (1st part) )
Allocca, Bersanetti, Nardecchia, Ruggi, Tacca, Vardaro - 3:17 Thursday 21 March 2019 (45333) Print this report
TCS tuning and ITF working point optimization - short summary

Tonight we worked at the optimization of the TCS working point, tuning accordingly the ITF alignment working point step by step. Hereafter a short summary of what we did (a longer and more detailed log will be posted tomorrow):

  • started with the TCS OFF and locked the ITF in LN3. The BS loop was left open.
  • switched on both the DASes at lower values with respect to the previous ones. The BS loop was closed after we found a good working point
  • increased the power on the WI DAS 
  • switched off the WI DAS
  • switched back on the WI DAS and increased the power on the NI outer ring

We optimized the alignment working point by maximizing the sidebands on B4 and minimizing B1p. The new values of the offsets have been saved in metatron. The CMRF seemed to improve a bit when the NI outer ring was switched on, but it was not possible to find an alignment working point minimizing the CMRF at the same time.

 

Virgo Runs (ER14)
berni - 22:59 Wednesday 20 March 2019 (45331) Print this report
Operator report - afternoon shift

The shift started with the ITF unlocked, and WE loops open; the closing of the loops took some time because one accelerometer was not working well. Valerio was able to fix the problem.

After that, at around 16:00, we started to lock with the aim to test the lock acquisition after the activity active common mode noise subtractor.

Unfortunately, we encountered two problems:

1 - lock of the cavity; fixed by Diego deactivating the IB automatic alignment.

2 - pass LOW_NOISE_2; after investigation, we discovered that the WE violin modes had been excited.

After some time we were able to dump them and to reach LOW_NOISE_3 at 19:52 UTC.

At 20:00 UTC started the commissioning activity ITF/TCS tuning; activity still in progress at the end of the shift.

INJECTION

IB left in drift control; IMC_AA red flag on DMS.

SBE

from 14:46 UTC to 15:56 the SWEB position loop has been open because the WE loops were open.

DOWNTIME EVENTS (time in UTC)

- from 15:00 to 16:00, ITF in troubleshooting, because one WE IP accelerometer was not working well; Valerio fixed the problem.

- from 17:00 to 19:37, ITF in troubleshooting (from 17:27), because the ITF was not able to pass LOW_NOISE_2 due to WE violin modes excited; Diego was able to dump them.

Injection system (Mode cleaner autoalignment)
bersanetti - 22:55 Wednesday 20 March 2019 (45332) Print this report
IMC Alignment in Drift Control

Today I noticed that the 8.65 Hz resonance was rising up, making the lock difficult; I disabled the full-bandwidth alignment in the INJ_MAIN node and the resonance disappeared. The IMC_AA flag is therefore red in the DMS.

Images attached to this report
AdV-SAT (Suspension control upgrade)
Paoletti, Passuello, Magazzu', Nocera - 16:21 Wednesday 20 March 2019 (45330) Print this report
Comment to Modification on NI and WI Coils cabling/connection (44973)

The test (active common mode noise subtractor) has been done this morning, but had no visible effect in 50Hz and 150Hz lines.

We have then decided to roll-back everything (END mirrors as well INPUT mirrors); now the situation is the same as before Feb 22nd (see entry 44973)

Virgo Runs (ER14)
Nenci - 15:32 Wednesday 20 March 2019 (45329) Print this report
Operator Report - Morning Shift

This morning the ITF was locked in Science Mode, the shift was characterized by an high wind activity who, sometime, prevented the achieving of LowNoise 3. However the work scheduled (SUSP - Test 50 Hz noise eater) has been carried on without troubles.

Suspension - 10:02 UTC - during the Suspension work at the NE the guardian opened "F7_DC_ON", I properly restored the standard working condition.

12:40 UTC - ITF manually unlocked in order to undo the electronics work for the 50Hz done for the input and end mirrors.

AdV-AEI Squeezer Integration (General)
berni, vardaro - 13:22 Wednesday 20 March 2019 (45328) Print this report
Squeezer DMS line

We tuned the threshold of the squeezer DMS Line in order to avoid red flags when the subsystem is not required. 

PLL

  • Internal PLL: can be red in each ITF state to notify problem in the Squeezer rest position
  • External PLL: the flag can be red from ITF in LOCKED RECOMBINED

Squeezer

The 4 sub-flags can be red from LOW NOISE 2 

SQZ_AA

  • the first 5 subflags: SQZ_AA_SLOW__AA_LOCK_SWITCH, SQZ_AA_SLOW__CamFarX_ERR, SQZ_AA_SLOW__CamFarY_ERR, SQZ_AA_SLOW__CamNearX_ERR, SQZ_AA_SLOW__CamNearY_ERR can be red from LOW_NOISE_1
  • the last 4 subflags: mean_SQZ_MIRROR1_X_cmd_1kHz_50Hz_60, mean_SQZ_MIRROR1_Y_cmd_1kHz_50Hz_60, mean_SQZ_MIRROR2_X_cmd_1kHz_50Hz_60, mean_SQZ_MIRROR2_Y_cmd_1kHz_50Hz_60 can be read in each ITF state

Shutter and SQZ_INJ

the flags can be red from LOW_NOISE_3

A remark, when the CMRF of the ITF is not well tuned (a step above 3.5 kHz in hrec) the subflag brms_LSC_DARM_20_2_2600_2800 of SQZ_INJ can be red even if we are correctly injecting vaccum squeezed state with the right CC phase

AdV-DET (Photodiodes + demodulation boards (longitudinal control))
mwas - 8:28 Wednesday 20 March 2019 (45327) Print this report
A guees at the improvement in PD quantum efficiency few new HQE photdiodes

Figure 1 shows the ITF optical gain before installation of the two B1 photodiode, and Figure 2 after installation of the two new HQE B1 photodiode.

There is a factor 2 difference, which I guess is due to some mistake in the ITF gain computation that didn't take into account properly the change from 1 to 2 photodiodes. Correcting for that the optical gain seems to have changed from 2010e6 to 2170e6, or an increase of 8%. Given that the optical gain scales as the square root of the detection efficiency, this correspond to a 16% increase in the detection efficiency. So the old photdiodes had a quantum efficiency of ~83%, and the improvement with then new HQE photodiodes is slightly larger than expected. Of course, looking at these data the optical gain can change by 5%, probably due to misalignment and other working point issues. But it is highly unlikely that this magically improved while changing the photodiodes, so the improvement should be due to the new PDs.

Images attached to this report
Virgo Runs (ER14)
Gherardini - 6:57 Wednesday 20 March 2019 (44421) Print this report
Operator report - afternoon night 19/3
The afternoon activity on ITF, TCS and SQZ tuning went on in the first part of the night (#45324, #45325); before starting the science mode I ran the MIRtoMAR calibration (Loic request), unfortunately it triggered an unlock (see plot), the ITF relocked at the first attempt, science mode started at 1:36UTC.

- calibration
1:08UTC, marionette calibration (CALIBRATED_DF_MIRtoMAR) --> failed: ITF unlocked during the injection

- guard tour (UTC)
1:25 --> 2:00
3:35 --> 4:05
5:10 --> 5:40
Images attached to this report
AdV-COM (AdV commissioning (1st part) )
estevez - 6:35 Wednesday 20 March 2019 (45326) Print this report
Comment to ITF working point tuning (45324)

I switched back the PCals on around 5h31 UTC.

AdV-AEI Squeezer Integration (General)
vardaro - 2:48 Wednesday 20 March 2019 (45325) Print this report
Squeezer working point

After the ITF working point tuning i switched on the squeezer and I tuned it:

I increased the AA dither line by a factor 5 and I found the AA working point. New set points

  • CamNearX = -260
  • CamNearY = 70
  • CamFarX = -80
  • CamFarY = 322

I performed a phase scan from 0 to 3.14 rad with a ramp of 600s and I found that the maximum squeezing level correspond to the minimum of the magnitude subtracted by 0.25 rad (attachment 1).

I retuned the CC dither demodulation phase. The new CC parameters are

  • sqz_b1_phase = 0.667

  • phase_dither_phi0 = 5.3

  • phase_diter_set = 0.16e-3

I measured about -2.6 dB of squeezing in HREC both in the 1350-1750 Hz and 2600-2800 Hz bandwiths (attachment 2 normalized plot)

I left the squeezer switched on with the slow AA closed on dither lines and SLOW CC closed with the PyALP based servo loop

Attachment 3 hrec fft with (blue) and without (magenta) squeezing injection

    Images attached to this report
    Comments to this report:
    vardaro - 21:58 Thursday 21 March 2019 (45342) Print this report

    Phase scan (figure 1)

    • squeezing level -2.4 dB, antisqueezing level 5.3 dB.
    • Red line Darm 1350-1750 Hz, Blue Line: Darm 2600-2800 Hz, Yellow Line Hrec 2600-2800 Hz, Violet line Hrec 1350-1750 Hz, Green 2650-314 0Hz 
    • The green line is a BRMS computed with window of 1s whereas the other BRMSs are computed with 20s windows
    • The phase scan in DARM is less visible than in HREC: this was due to the bad CMRF of the ITF, so we had a lot of frequency noise
    • The phase noise was performed in a not good alignment condition so the maximum squeezing level was 2.4 dB
    • This is visible observing the B1_PD1_mag 3.0e-3V when was misaligned and 3.5e-3 V when I realigned it exploting the dither loop
    • The brms channel computed with 1 s windows is faster than the other, so it allow to computed better the phase distance between mag and sqz (0.33 rad)

    Night Injection (figure 2)

    • The night injection, after the realignment started with -2.8 dB of squezzing in the bandwidth between 2650-3140Hz
    • After 6 hours the sqz level was decreased to -2.2 dB, but this was probably due to a 56MHz RIN, see B1s2 DC photodiode (second line of the plot)
    • After the locking seems that for long time we injected antisqueezing, but this can be due to hrec not updated or a bad working point of the itf. The phase error signal of the slow CC loop was in a good position and not drifted (third line)

    Coherent control phase noise (figure 3)

    I performed the CC phase noise calibration with two different methods

    Method 1:

    1.  open shutter, CC open,
    2. Measure the Aplitude of the fringes and from them obtaining the V/rad
    3.  PD1cal =  0.00399 V/rad,   PD2cal =  0.10984 V/rad

    Method 2:

    1.  Open shutter, Close CC,
    2.  perform a phase scan
    3.  plot SQZ_B1_PD{1,2}_Q as a function of the CC phase,
    4.  fit the linear part of the curve 
    5.  PD1cal =  0.00388 V/rad,  PD2cal =  0.11375 V/rad

    The two methods are consistent. I computed the rms phase noise of the CC between 0.05Hz and 25 kHz and I obtained 20 mrad in loop (PD1) and 23 mrad out of loop (PD2).

    Images attached to this comment
    AdV-COM (AdV commissioning (1st part) )
    nardecchia, bersanetti, brooks, casanueva, mantovani, ruggi, tacca, vardaro - 0:24 Wednesday 20 March 2019 (45324) Print this report
    ITF working point tuning
    This afternoon we tried to recover a good working point for the ITF.

    At first we found a good one for the sidebands, dark fringe and sensitivity (maximum 48 Mpc with no squeezing and without PCal lines) but with a bad CMRF (step in hrec at high frequency clearly visible) (see fig.1) .

    This configuration has been achieved with the following TCS DAS parameters:

    -WI DAS IN: 88 mW

    -WI DAS OUT: 133 mW

    -NI DAS IN: 335 mW

    -NI DAS OUT: 1.491 W.

    The alignement set points were:

    BS_TY_SET=0

    BS_TX_SET=-0.012

    PR_TX= 0.004

    PR_TY=-0.004

    Diffp_TX=0.005

    Diffp_TX=0.017

    Then with the same TCS configuration we changed the BS _TY_SET to recover a good CMRF. To do this we set BS_TY_SET=-0.007. The sensitivity curve worsened (SDB1 bumps between 300 and 600 Hz and low frequency) (see fig 2).

    Then we started to change the working point of the DAS to improve the sideband and dark fringe in that configuration but without success.

    We tried to compensate the misalignment of the BS acting with the DAS, but it doesn't seem to be the right action. Maybe it is better to reach a good working point for the fringe and the sidebands and then try to minimize the CMRF by tuning the TCS powers (common mode).

    After these tests the ITF unlocked and then it locked again with not-so-different DAS parameters:

    -WI DAS IN: 80 mW

    -WI DAS OUT: 80 mW

    -NI DAS IN: 460 mW

    -NI DAS OUT: 1.473 W.

    We achieved again 48 Mpc without squeezing and no Pcal lines (see fig.3).

    We left the ITF with the current configuration of TCS and the alignment set points saved in metatron.


    Images attached to this report
    Comments to this report:
    estevez - 6:35 Wednesday 20 March 2019 (45326) Print this report

    I switched back the PCals on around 5h31 UTC.

    AdV-DAQ (Software Framework)
    masserot - 0:21 Wednesday 20 March 2019 (45323) Print this report
    Unexpected server connected to FbmFE : ingv_plg

    Looking at the Cm connections on the DAQ servers I found an unexpected server connected to the FbmFE and asking to receive the frames. It was the server ingv_plg launched by giuliob and running on VTF host

    •   -text CmName ingv_plg, port 29002,  Host cmplvtf2.virgo.infn.it, owner giuliob, socket_id 25 (16384,425984),  local 0, alive 1

    Only DAQ experts can connect on the frame mergers ie FbmFE , so I  killed the ingv_plg Cm connections .

    There is a VirgoOnline Test VPM server to perform these  kinds of tests

     

    Virgo Runs (ER14)
    berni - 23:00 Tuesday 19 March 2019 (45322) Print this report
    operator report - afternoon shift
    ITF found in LOW_NOISE_1 and in Commissioning mode with the recovery in progress.

    At 15:01 UTC the ITF was locked in LOW_NOISE_3 and Romain started working from remote, see entry Tentative alignment of SPRB and B4 photodiodes.

    After that started the activity ITF tuning; activity still in progress ...

    Suspensions
    At around 21:30 UTC the WE and WI local controls were open by the guardian; properly closed.

    DMS
    tuning of the SQZ flags on the DMS.
    AdV-DAQ (Calibration)
    estevez - 18:42 Tuesday 19 March 2019 (45321) Print this report
    Swapped permanent lines on WE and NE PCal

    Today at 17h34 UTC, I swapped the permanent lines frequency on the PCal WE and NE 60.5 Hz <--> 63.5 Hz just for a few minutes, in order to cross calibrate WE Pcal with NE Pcal.

    At 17h40 UTC I swapped them back to standard configuration.

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