* DRAFT - Shift in Progress *

ITF found in LOCKED_ARMS_IR and in Upgrading Mode.

HVAC
At my arrival, I found R.Romboli and S.Andreazzoli on site due to chiller FCIM failure
For detail, refer to dedicated On-call Intervention Report

TCS
TCS activity started at 07:00UTC

This morning, while Bea was wiring the new RF driver for the WI laser, we inspected the NI bench. We found numerous mouse droppings on the plexiglass used to protect the bench from dust.

After cleaning the plexiglass, we found a mouse carcass under the periscope mirror through which the CH beam (~13 W) propagates. The mouse was practically disintegrated by the beam, and various remains were found around the mirror, although fortunately, the optics are clean.  After temporarily blocking the CH beam, we removed the carcass.

During the wiring operations for the new RF driver on the WI bench, Bea found another mouse carcass in the lower part of the bench next to the RF driver. We are not including the photos because they are not for the faint-hearted, but if anyone wants to see them, please let us know.

The following report has been submitted to the On-call interface.

On-call events -> Air Conditioning

Title: Chillers FCIM failure

Author(s): romboli

Details:

Alarm received during the night of increased cooling water temperature at the FCIM station. (This problem also occurred yesterday afternoon and with the help of S. Andreazzoli we had unblocked the two chillers which were blocked and the problem seemed to have been solved). This morning, present on the site with S. Andreazzoli and assisted remotely by D. Soldani, we verified that there is a problem with the automatic operation of the two chillers. So we activated the manual function, checked that the temperature parameters returned to normal and reserved the right to check carefully on Monday morning.

* Note that any files attached to this report are available in the On-call interface.

Following the intervention in the DET tower, we carried out the standard cleaning of the chamber floor and then we closed the bottom flange.  The evacuation is in progress.

Notes:
- 4 new Si-wafers have been placed inside the tower, as last action just before closing. They are positioned on the floor near the entrance flange (positions N, W, S, E)
- to be done on monday morning: connect and pump the double orings of the bottom flange

We also made a rough calibration of the motorized counter weight: For a motion of 174 000 steps on BENCH_TZ, the weight had moved by 6 or 6.5 mm.

Today, after Paolo restored the control of the SDB1 bench suspension, we noticed that the bench was not at the expected position according to the bench LVDT. We also faced some difficulties in closing the angular control loops. We noticed that the bench was not free and that a vertical displacement would be linked to angular rotations in TX and TZ suggesting that the bench was touching.

We then entered the detection tower to check the LVDT wires and noticed that the Back Right Vertical coil had an unconnected wire. This happened yesterday evening between 17 and 17h30 utc according to the data of the LVDT sensors.

Thanks to Gianmatteo, the wire of the coil was repaired and we could finish the rebalancing of the bench.

After the repositioning of the bench position with the suspension (performed by Valerio) we made a tiny adjustment of the bench angular position using the motorized counter-weight: We performed -24000 steps on BENCH_TX (by steps of -2000).

With the SDB1 bench controlled in air, we then checked the position of the injected Hartmann beam inside the tower (see Figure 1) and saw that the new beam dump is quite far from this beam. During this measurement the angular control of SDB2 were also closed, however the position loops had been incidentally left open. This does not matter for the check because the X,Y;,Z positions of the bench were only a few tens of um away from the setpoints.

At 15h55 utc we asked Antonio to reopen the valve and to stop the air flow in the tower. We started to check the alignment of the bench with the single bounce beam. With the same angular positions of the bench as we had last tuesday we immediately found the B1p beam and a little adjustment of this angular position allowed us to bring the B1p beam at the same position on the camera as we last tuesday (Fig.2). SDB1 angular setpoints changed in TX from -30 to -18, and in TY from 0 to -25 urad.

For this position of the bench we measured the beam on the B1s camera (Fig.3) at the following coordinates:
Pos X : -0.05, Fit pos X -0.03
Pos Y : 0.22, Fit pos Y 0.22

We opened the OMC shutter and scanned the OMC from 16h26 to 16h39 utc. We observed the following modes:

TEM00 : 1.7 mW (at 22.587 deg) at 16h31h33 utc (see Figure 4 and 5)
Order 1: 1.4 mW (with a pattern which was mainly vertical) - see Figure 6 and 7.
Order 2: 0.6 mW (Figure 8)

We checked from the south west viewport of the SDB2 minitower the silicon beam dump which is stopping the beam reflected by the OMC shutter, with an infrared viewer, but it was not possible to see any scattered light.

After this we gave the green light to the vacuum team to close the tower.

ITF found in LOCKED_ARMS_IR and in Upgrading Mode.
At around 14:30 UTC the DET Team was starting to close the SDB1 Suspension loops and rebalancing, but the bench was misalinged in its vertical position. Thanks to the intervention of Boschi the SDB1 Vertical Drift loop was closed at 14:50 UTC and the bench returned to its correct position.
At 15:40 UTC, under request of the Crew, Pasqualetti opened the SR_BS to allow the interferometer beam to reach the Detection, ITF in Single Bounce from 15:42 UTC.
At 17:50 UTC the SDB1 intervention was concluded, Pasqualetti closed again the valve and at 18:03 UTC I put back the ITF in LOCKED_ARMS_IR. We also prepared the system for the evacuation (OMC temperature control disabled and related shutter closed, SDB1 ID and LC opened, SDB2 Position loop opened).
Vacuum Evacuation started at 21:40 UTC, activity in progress.

ISC
As requested by Mantovani, at 14:13 UTC, I performed the daily opening and closing of the Etalon loops in order to discharge the offsets.

TCS
The TCS activity was concluded at around 16:20 UTC (see report #64794).

Today, we continued with the intervention on the WI CO2 bench.

Following the procedure described in the gitlab, we started by step 10 of phase I:

10. Move the SPIRICON 2 after the pinhole telescope and install an iris (see fig.1 and 2).

Then, we deviated the beam before the lens L1 by inserting another mirror (between M2 and L1, the so-called MX1, see fig.3) to take as reference the free propagation of the beam maximizing the optical path length (step 11 in the procedure). Two irises have been aligned during the path in the near and far field using the spiricon (step 12 in the procedure) (see fig. 4 and 5).

Once completed Phase I, at 14.56 LT, the WI CO2 main laser has been switched OFF. With the support of Nicola, we disengaged the guardian system, we switched off the WI chiller and we engaged the backup chiller only on the NI CO2 laser.
Then, we removed the old couple laser-RF driver (S/N 40801-35119D - S/N 170108-154307) to install the new one (S/N 154307-170108 - S/N 35119D-40801).

After that, we restored all the electronic and cooling system connections (see fig.6).

We switched on the WI chiller to check for some water leakage, everything was okay.
Phase II has been completed.
Tomorrow, we will start Phase III in the gitlab procedure.

We left:
-WI CH laser OFF

-WI main laser OFF

-WI main chiller OFF

-Guardian system: backup chiller engaged on the NI CO2 laser

-NI CO2 lasers (CH and DAS) in standard condition

ITF found in LOCKED_ARMS_IR and in Upgrading Mode.

The shift was dedicated to SDB1 intervetion and TCS CO2 WI laser replacement.

At approximately 11:00 UTC, R. Gouaty, A. Demagny, and P. Spinicelli discovered a broken pin on the LVDT connector at the SDB1 bench. To address this issue, they turned off the HWS and blocked the beam of the SQZ in order to work without goggles. They then requested my assistance to repair the pin. By approximately 12:00 UTC, I accompanied R. Gouaty and A. Demagny inside the SDB1 tower to address a broken wire in a female 2-pin Lemo connector on the SDB1 bench. I replaced the broken pin and crimped the cable to a new one, ensuring that the signal is once again available.

TCS and DET work are still in progress.

Today we adjusted again the tilt angle of the half waveplate on the SDB1 bench and performed some checks on the power measured before and after the Faraday Isolator with the auxiliary laser at 1047 nm (more details will be posted in a separated entry).

After the completion of the waveplate tilt angle tuning, we dismounted the alignment setup (spare laser of the Pcal and irises), performed some cleaning on the bench with the top gun, and started the balancing of the bench. The balancing in TX and TY was completed late this evening, but the bench cannot yet be controlled because the longitudinal suspension is too far from nominal and the bench is touching.

The activity will go on tomorrow morning with the following tasks:

* Restore the control of the suspension (with SAT expert) and close the angular control loops of the bench.

* Check of the bench alignment with the single bounce beam, with bench controlled in air.

* Check of the injected Hartmann beam path inside the tower, with bench controlled in air.

The following report has been submitted to the On-call interface.

On-call events -> Air Conditioning

Title: Boiler WEB

Author(s): romboli

Details:

I intervened after receiving an alarm (around 10pm) at the WET. The LPG boiler had failed following the failure of the inverter in the pump room. I consulted with D.Soldani as the boiler was having difficulty restarting and therefore we decided to turn on the oil boiler (around 11.30pm).
Tomorrow I will call the LPG boiler technician.

* Note that any files attached to this report are available in the On-call interface.

ITF found in LOCKED_ARMS_IR and in Upgrading Mode.
The shift was dedicated to the planned SDB1 Intervention, carried out by Gouaty, Spinicelli and Demagny, and to the TCS WI CO2 laser replacement (see report #64788).
DET activity concluded at around 21:30 UTC, infrared cavities left locked.

SUSP
At around 18:05 UTC the DET crew needed the ID Loop of SDB1 closed. I tried to close the loop using the dedicated interface, but the correction satured few seconds after. From remote, Ruggi used the related motors to adjust the filter position and was able to close SDB1 ID at around 18:25 UTC.
The loop was opened by the guardian at 19:43 UTC due to the human activity inside the tower, I tried to close it again at around 20:50 UTC under request of the crew, but again the correction started to saturated. Loop left open.

Today, we continued the activity that started yesterday (64779).

Following the procedure in the gitlab, we did the following steps:

2. Acquire the image of the inner ring after the cinogi telescope with SPIRICON 1 (in LASERDEC position). (see figure 1)

3. Remove the mask and put the SPIRICON 1 in its position and acquire the intensity distribution of the outer ring (see fig. 2)

5. Acquire  the  images of both thermal cameras of the DAS OUTER RING and CH on the black paper of the diagnostic system. The black paper will remain there for all the operation (see fig.3).

Then, the WI CH laser been switched OFF at around 11 LT (point 6 in the git procedure).

7. Acquire the image of the beam before the lens-axicon with SPIRICON 1 along the outer ring path and install an iris (see fig.4 and fig.5)

The point 8, i.e. decrease the laser duty cycle, was not needed since we are able to acquire the images of the beam before the pin-hole at full power (that is point 9).

To conclude the phase I, we need to perform the last three steps (planned for tomorrow morning).

CURRENT SITUATION: WI CH laser switched off, WI main laser switched ON but the DAS is blocked on the bench.

Note: Bea and Gianmatteo cabled the thermal camera flip mirrors for both NI  and WI benches (a dedicated entry will follow).   
  

Activities carried out in the morning and still ongoing:

- DET: work inside SDB1 tower;
- TCS: WI CO2 laser replacement preparatory works;

ISC
- 10.11UTC new etalon set point:
NI from 20.1 to 20.357 C (259200sec ramp time)
WI from 19.95 to 20.207 C (259200sec ramp time)

SBE
at 7:51UTC the SNEB position loop was opened by the guardian, controls properly closed.

In any case I've decreased of a factor 10 the gain of the filter for the NI and WI down condition to reduce the effect (to be improved once we will be again in working condition).

In order to better cope with the increase of the outside temperature we decided to move the NI and WI etalon fringe to the next fringe.

the set points have been changed to 20.357 for NI and to 20.207 for WI in 3 days.

This morning we deacrised again the working point:

• 9:52 LT -> NE cold loop from 13 C to 12,5 C
• 10:40 LT -> WE cold loop  from 13 C to 12,5 C

At 12:50 LT we restored 13 C for the NE because the temperature of the water prevent the right functioning of the machine around this working point, more investigation will be done soon.

this morning the new controller for the NI has been updated after having re-evaluated the plant for NI (see entry https://logbook.virgo-gw.eu/virgo/?r=64736 )

the new controller is

# Etalon North boost 02
ACL_FILTER_SET      Etalon_north_boost_02    1        35000    1    10
ACL_FILTER_ZEROS    Etalon_north_boost_02    2e-07    0
ACL_FILTER_ZEROS    Etalon_north_boost_02    2e-06    0.6
ACL_FILTER_POLES    Etalon_north_boost_02    0        0
ACL_FILTER_POLES    Etalon_north_boost_02    0        0
ACL_FILTER_POLES    Etalon_north_boost_02    1e-5    0

Moreover the down conditon for long unlocks (like this commissioning break) is not optimal and it is better to discharge the offset at least once a day.

ITF found in LOCKED_ARMS_IR and in Upgrading Mode.
The shift was dedicated to the planned SDB1 intervention (Gouaty, Spinicelli, and Demagny) and  TCS preparation for the acquisition of all the needed references before replacing the laser (Aiello, Lumaca, Taranto, Nardecchia)

Other activities carried out during the shift: 

14:16-16:21 V. Boschi worked on tests and injections on NE 

This morning we continued the activities related to the detection tower intervention.

First we went to the CB platform in order to install an adaptor cable used for the driving of the new motorized agilis mount for the waveplate. In order to be able to cable this new device we sacrified the wires of the picomotor B5_M1_TX which was connected on the picomotor driver 8742 SN 10592, channel 4. We unplugged this cable, and connected it to the adaptor allowing to plug it on the Agilis driver AG_UC8, on the channel 3 axis 2. We updated the VPM configuration accordingly.

Then we entered the detection tower to check the new cabling. To this purpose we plugged a spare agilis rotation stage to the B5_M1_TX cable, and acted on the rotation stage from the SDB1_Rot process. The test was successful. After that we unplugged the tested spare rotation stage.

Then we performed a first measurement of the power delivered by the auxiliary laser placed on the bench. The power measured between the B1/B5 diaphragm was 237 mW, We also measured the power after the Faraday Isolator, by placing the power meter between the single hole diaphragm and SDB1_M3: the power was 63 mW.

Since the power was quite big, we installed a density in front of the laser collimator in order to reduce the laser power. After the installation of the density, we found a power of 18.7 mW before the B1/B5 diaphragm.

We then completed the alignment of the auxiliary laser setup, ensuring that the beam would reach the OMC and be reflected by it.

After the mirror alignment we took another laser power measurement at the same places:

* Before the B1/B5 diaphragm: 18.3 mW

* Between the single hole diaphragm and the SDB1_M3 mirror : 4.9 mW.

After this, we installed four irises along the auxiliary beam to have alignment references:

* One iris is placed before the B1/B5 diaphragm (Fig.1)

* One iris is placed between the single hole diaphragm and the SDB1_M3 mirror (Fig.2)

* One iris is placed before the SDB1_Mmot1 mirror, and one right after the OMC reflection (Fig.3)

Before installating the new half waveplate, we had to displace the clamping fork of the SDB1_M1 mirror to make room on the bench. To this purpose we installed some temporary clamps around the column of this mirror. After each step of this operation we checked the alignmetn on the irises and did not observe any change in the alignment. We managed to displace the clamping fork to the foreseen location. The very last step was to remove the last temporary clamp. After doing this, we noticed a change in the alignment references. But we suspect that this is the collimator alignment of the auxiliary laser that changed after we touched incidentally the fiber. To check this hypothesis we did the following tests:

* we reinstalled the last temporary clamp. This did not produce any change in the alignment ;

* we touch the rear side of the collimator, and this way we managed to realign the beam at the previous references.

We weighted the new half wave plate including its mount, colunm and clamp: 552 g.

We then installed this half wave plate on the bench at the foreseen location (Fig.4 and Fig.5).

After installing the half wave plate, we added a temporary reflective mirror (with no wedge) using an adaptor, on the waveplate rotation stage. This mirror was used to tune the tilt angle of the waveplate that was applied to send the mirror reflection towards a new glass beam dump. The glass beam dump was installed between the dichroic mirror and the parabolic mirror MMT_M2 (a picture of the glass beam dump will be posted later).

The glass beam dump, including its mount, colunm and clamp was weighted: 223 g.

We checked by looking through the Hartmann beam lens that the new beam dump is not hiding the MMT_M2 mirror.

Finally we plugged the new waveplate rotation stage to its cable and tested it successfully (with 10 steps in one direction and -10 steps in the other direction).

Tomorrow we still have to perform the following tasks:

* measurement of the power before and after the FI

* Dismounting of the alignment references and auxiliary laser and fixing the temporary displaced cables

* Adjusting the bench weight, and rebalance the bench to suspend it.

* Check the position of the beam dump with respect to the Hartmann beam with the bench suspended and controlled in air.

* Check with the NI  single bounce beam that the general alignemnt of the bench has been preserved.

This afternoon, we started to act on the WI CO2 bench, in particular we worked on the preparation  for the acquiaition of  all the needed references before replacing the laser.

The entire procedure is described in https://git.ligo.org/virgo/commissioning/commissioning-tasks/-/issues/73/. 

Here the list of all actions:
1) we switched off the photodiode ISSIN in order to remove the higher part of the plexiglass on the bench

2) we installed a new thermal camera on the BS flange to have another reference (see figure 1).

All references, CH, DAS outer and inner ring have been acquired with the diagnostic system and with the second thermal camera. 

Then, we started to acquire some images of the inner ring and outer ring in some strategical places of the bench with the CCD (Spiricon) (points 1. and 2. in Phase I in the gitlab procedure).
At 19.10 LT, we concluded the activity by restoring the nominal CH and DAS outer ring power injected to the ITF.

Note: we moved two NN sensors  close to the NI bench to avoid to accidentally hit them during the work on the bench.
 

Today we carried out a 'leak identification' test on the SQZ apparatus.

In particular, we closed the vacuum valve between SQB2 and the cavity (note that the valve has a window on the gate and the laser beam is still transmitted to some extent) . The area suspected of leaking has been identified as being between SQB2 and SQB1. We still need to verify whether this issue is real or "virtual" and in case localize it more precisely. 

We will continue the investigation on Friday, or possibly tomorrow morning depending on the overall activity.

Taking the profit of these upgrading days, we further investigated the noise source of the 63 Hz bump. From the offline analysis, we noticed:

• the geophone #212 (positioned on the West side of the WI tower) and #239 (positioned between PR and BS tower) measured this noise, Figure 1. The noise also has an acoustic component visible in microphones  #207 (level 2, located between INJ and PR towers)  and  #213,214, 223 (level 3 - scaffolding platform, BS, WI, INJ towers respectively), Figure 2 and Figure 3.
• Looking at the spectrogram of ENV* microphones and accelerometers, we observed this noise is also polluting other sensors: the mic of EIB, accelerometer on TCS WI bench and accelerometer of INJ cryotrap (*IB_CT_FINGER*), Figure 4.

Following the results above, we decided to sniff the scaffolding platform, in particular the SAT racks of PR and WI towers which are in the incriminated area. As reported in the attached file, we placed the accelerometer (ENV_SNIFFING_ACC) in different positions on the racks, Figure 5.
The culprits are the cooling fans of the PR SAT crates. We also observed the following:

• the noise measured on the PR SAT crates corresponds to the noise seen by EPRB, Figure 6
• we could not disentangle between the fans of the top crate (Sa) and bottom crate (Sc); this could achieved by changing the speed of the single fans modules (by SAT)
• it is worth noticing the fans are working properly, nothing is breaking. We tested similarly also the WI SAT crates and we found a similar behavior (frequency oscillation), right box of Figure 7.  It just happens that the frequency of PR cooling fans matches the mechanical mode of the EPRB bench (60 Hz)
• Akis confirmed that all fans' speeds are the same and they run in feedback to keep the crate temperature stable.
• the fans are assembled in 4 planes, 3 fans each, 2 planes per crate

Mid June, we lost the connection to 2 cameras of SQB1 (SQB1_Cam0 and SQB1_Cam1), as well as the connection to the newtork switch in the air tank. After inspecting the output values of the power supply (hameg20) providing the power to the switch, we found wrong values of the output voltage. We have proceeded with the replacement of the power supply by hameg18, during the maintenance period of yesterday.

After correcting the interface selection on hameg18 (which was wrongly set to USB instead of ethernet), we have regained the control the the power supply, the network switch and the 2 cameras.