Reports of 26368
VAC (Valves & Pumps)
nobuhiro.kimura - 9:04 Wednesday 21 February 2024 (28653) Print this report
Comment to Strange shhhh sound around TMSX pendulum valve (28628)

The correct taper thread seal standard (dimensions) for gate valves is as follows.
φ800 and φ1000 large gate valve:  1/4" taper thread seal (R 1/4" ISO NPT)
φ400 pendulum type valve: 1/8" taper thread seal (R 1/8" ISO NPT)

CRY (Cryo-payload EY)
takashi.uchiyama - 8:45 Wednesday 21 February 2024 (28652) Print this report
Comment to Pressurized EYC up to 1 x 10^3 Pa by N2 gas on 7th/Feb. (28570)

not EXC. EYC is correct.
CRY (Cryo-payload EX)
takashi.uchiyama - 8:44 Wednesday 21 February 2024 (28651) Print this report
Comment to Pressurized EXC up to 1 x 10^3 Pa by N2 gas on 7th/Feb. (28569)
2024/02/19

Takase, Uchiyama

We pressurized EXC from 9:00 to 11:40 and the pressure reached atmospheric pressure
FCL (Clean Area)
takayuki.tomaru - 7:53 Wednesday 21 February 2024 (28650) Print this report
Draft Chamber area
Clean booth for a draft chamber at the center room don't have celling light and I felt it was too dark when I had something work there.
So I installed LED celling light there.
Images attached to this report
CRY (Cryo-payload EY)
takayuki.tomaru - 7:45 Wednesday 21 February 2024 (28648) Print this report
EYC repair (Magnet/Magnet glue)
Tomaru, Rishabh

We removed the gluing jigs of magnet-base on a suspended TM.
And we checked strength of glued magnet-bases and magnets by tweezers, but the top magnet-base (and magnet) were come off.
We took it to center room and re-glued magnet on the base.
Re-gluing of the magnet-base will be today (Feb. 21).
CRY (Cryo-payload EX)
takayuki.tomaru - 7:43 Wednesday 21 February 2024 (28649) Print this report
ETMX repair (magnet glue)
Tomaru, Rishabh

We checked strength of survived magnets and magnet-base on ETMX by tweezers and found two magnets came off from their bases.
We re-glued the magnets on their magnet-bases by using our developed jigs.
CAL (General)
hirotaka.yuzurihara - 1:16 Wednesday 21 February 2024 (28647) Print this report
Comment to Investigation of the issue that the image centers by two cameras were not matched (28571)

[Ikeda, Yuzu]

We discussed this result. In our consideration, the reason why the image was off-center was that the camera adaptor for the ASI camera was not held tightly in place. Perhaps a shift of the image sensor is an incorrect extrapolation. I will reconsider the setup for the TCam test bench.

  • In the four corners of the image taken by the gige camera, there are vignetting (in Japanese, called Kerare) (Fig1). The area size of these Kerare looks almost same size. So, the sensor of the gige camera should be no problem. So, we doubted something happened in the ASI camera side. 
  • Fig2 shows the adapter to hold the ASI camera (left black one). Right red one is the ASI camera. This adapter can be loose in some cases. 
  • Fig3 shows the inner part of the adapter. Two screws tighten the camera. As seen in this figure, when I tighteded only one screw, the camera will be shifted to one way. We suspenct this happened in the previous operation test. In quick calculation, the 0.5 mm off-center of the image sensor can explain the previous off-centered images. I will reconsider the setup for the TCam test bench.
  • Note that from the visual inspection by Ikeda-san, the image sensor of the ASI camera is well centered in the camera. The 0.5 mm shift of the image sensor was not obserbed.
Images attached to this comment
CAL (YPcal)
takahiro.yamamoto - 0:25 Wednesday 21 February 2024 (28646) Print this report
Laser power couldn't be changed.
[Fujii, YamaT]

We tried to reduce the laser power to make a power budget in the Tx module.
But we couldn't change the laser power and we gave up to do today's task.

-----
For changing the laser power, a script is already prepared. But today somehow it didn't worked well.
Though we also tried to change laser power on the front panel of laser chassis body, it also didn't work.
Because Pcal hardwares are different between EX and EY, our preparation for the work at EX was not useful for the work at EY at all.
So we finally gave up to continue today's work.
VIS (PR2)
takafumi.ushiba - 22:26 Tuesday 20 February 2024 (28645) Print this report
Comment to Recovery of PR2 suspension (28593)

Detail on BF V1 LVDT:

According to the log of PR2 LVDT calibration (klog2906), BF LVDT V1 was calibrated between -5500 and 3000.
Current value is about -5800: that means we are not sure LVDT is now in linear range or not.
I think this situation is not good.
However, this situation seemed happened long before the earthquake, so it would not be a critical issue and I'm not so sure if it should be fixed or not.

Note:

BF V1 LVDT signals can be changed when SF GAS position changes; however, V1 value won't be changed so much even at ALIGNED state because current error signals of SF GAS is just 10 um or less.

CAL (General)
hirotaka.yuzurihara - 21:42 Tuesday 20 February 2024 (28644) Print this report
Irregular maintenance of TCam for ETMY

[Yokozawa, Yuzu]

As an irregular maintenance of TCam for ETMY, we performed the visual inspection this afternoon. During O4a and the commissioning period, the TCam for ETMX showed a problem with the beam appearance (Fig1). We suspected it was due to the problem with the mirror surface in the TCam system or the objective lens of the telescope. For example, it could be moldy. We compared the conditions between TCam of ETMX and ETMY.

  • We opened one of the side walls of the TCam (Fig2). However, the mirror in front of the telescope blocked to see the surface objective lens.
  • Next, we opened the top side wall and checked the surface objective lens. We noticed that the surface of the objective lens was found to be contaminated (Fig3). It does not appear to be an obvious mold, but I am not sure what it is. We want to clean it next time with ethanol and a cotton swab.
  • We checked the mirror in the EYA chamber, which reflects the incident light from the ETMY to the telescope (Fig4). We saw something like white dust on the surface of the mirror. We think this could be a cause of the problem with the ETMY images, which causes the scattering on the ETMY image.
  • Concerns
    • Is it possible to clean the mirror in EYA in a safe way?
    • GreenY is needed to see if the problem has been solved after the cleaning. Is it possible for the schedule?
Images attached to this report
CAL (General)
hirotaka.yuzurihara - 21:40 Tuesday 20 February 2024 (28642) Print this report
Irregular maintenance of TCam for ETMX

[Yokozawa, Yuzu]

As an irregular maintenance of TCam for ETMX, we performed the visual inspection this morning. From our inspections, the TCam of ETMX was no problem, except for the small dust.

  • During O4a and the commissioning period, the TCam for ETMX showed no troubles. The purpose was to see the TCam in good condition for comparison with the TCam for ETMY in the afternoon.
  • We opened the one wall of the TCam (Fig1) and checked the surface of the objective lens. A little dust seemed to be on the surface (Fig2) (Fig3). Next time, we will try to clean it by using an air duster.
  • We checked the mirror in the EXA chamber, which reflects the incident light from the ETMX to the telescope (Fig4). The photo shows a cloudy mirror, but this is due to poor camera performance... Eye inspection did not reveal any problems.
Images attached to this report
PEM (Tool)
tatsuki.washimi - 21:11 Tuesday 20 February 2024 (28643) Print this report
SHINDO calculation script

[Hoshino, Washimi]

We developed a python script to calculate the SHINDO seismic intensity (震度) based on the JMA definition from KAGRA seismometers for each station.

In this script, the data between [-63s, -33s) from the current time is used. (processing time is 2~6 seconds, mainly importing packages)

Now it is debug mode and just printing the values. (Not working in the realtime model)

Images attached to this report
VAC (Valves & Pumps)
nobuhiro.kimura - 20:41 Tuesday 20 February 2024 (28641) Print this report
Comment to Strange shhhh sound around TMSX pendulum valve (28628)

[Kimura and M. Takahashi]
 We identified the source of the indicated compressed air leak.
The cause was the use of a parallel threaded seal joint with an O-ring where a tapered threaded seal joint should have been used.
 We are currently inquiring with the company that installed the piping as to the reason for the mis-specification of the fitting.
This wrong choice of fitting has been confirmed on all KAGRA pneumatic gate valves.
Therefore, it is necessary to replace the fittings with the correct ones.

VAC (EY)
nobuhiro.kimura - 20:33 Tuesday 20 February 2024 (28638) Print this report
Comment to Flange opening work for EYC and EXC (28631)

[Kimura and M. Takahashi]

 This afternoon we opened the two flanges on both sides of the TMSY chamber.
After opening the flanges, we put curing tape to protect the sealing surfaces.

VAC (EX)
nobuhiro.kimura - 20:33 Tuesday 20 February 2024 (28639) Print this report
Flange opening work for EXA and TMSX

[Kimura and M. Takahashi] 

 This morning we opened the flanges on both sides of the EXA and TMSX chambers.
After opening the flanges, we put curing tape to protect the sealing surfaces.
 

VIS (EY)
ryutaro.takahashi - 18:14 Tuesday 20 February 2024 (28640) Print this report
Recovery of BF damper

[Washimi, Takahashi]

We recovered the BF damper from the overflow of H3 primary coil.

  1. Opened the side hatch at the cross tube. Locked the BF body with the EQ stoppers.
  2. Disconnected the Dsub connector for the primary coils on the side plate of the BF. Checked the resistance of the coil side. The resistance between 3-8 pins (H3) was overflow.
  3. Found the lead cable from H3 coil was cut at 6~7cm from the pin side. Disconnected the coil from the Dsub connector side. Dismounted the coil bobbin.
  4. Repaired the cable. Cramped the new pin to the top of the lead cable. Connected the coil to the Dsub side. Checked the resistance. It was 9.2Ω. Mounted the coil bobbin.
  5. Connected the Dsub connector. Checked the signal on the medm. The H3 LVDT was working.
  6. Released the BF body. Closed the side hatch.
     
Images attached to this report
VIS (PR2)
naoatsu.hirata - 17:41 Tuesday 20 February 2024 (28637) Print this report
Comment to Recovery of PR2 suspension (28593)

[Hirata, Dan Chen-san, Ikeda-san, Ushiba-san]

We checked Traverser position, and moved it to the previous position. Finaly, length Oplev was recovered.

  • Removed bolts, and opened PR2 chamber top part.
  • Measured Traverser position by caliper and compared with old data (2022/7/26) which was measured before closing chamber.
  • We confirmed Traverser works well or not. Direction is correct.
  • We moved Traverser to previous position(2022/7/26). -1100um to y direction, and -3000um to x direction.
  • We measured Traverser position by caliper again. It was almost recovered to previous position(2022/7/26).
  • At the same time, length Oplev was recovered.
  • We closed chamber top.
  • Adjusted tilt Oplev by IM Yaw pico -2400 steps.
  • Length Oplev is HOR:-13.4um.
  • We checked IM OSEM(3700~7640). All flags are not touching.

After that, Ushiba-san realized BF damper V1 is around edge of calibration line(about 5800). Tomorrow, we will open chamber top, and see BF and BF damper situation.

Images attached to this comment
VIS (EX)
takaaki.yokozawa - 15:44 Tuesday 20 February 2024 (28636) Print this report
Eye check of MN oplevs ETMX
[Yuzu, Yokozawa]

We performed the eye check for the MN oplev at ETMX.
Mainly. the mirror health check and injection point of mirror.

From my eye, the mirror itself is healthy, but injection point of oplev light is relatively higher in each mirror.
(Or MN stage is lower than before)
Images attached to this report
VIS (PR2)
dan.chen - 9:42 Tuesday 20 February 2024 (28635) Print this report
Strange behavior of PR2 V2 OSEM signal

There is a large 60Hz noise on the PR2 V2 OSEM output.

Images attached to this report
CRY (Cryostat EY)
takayuki.tomaru - 8:20 Tuesday 20 February 2024 (28633) Print this report
ETMY repair (Magnet glue)
Tomaru, Rishabh

We did magnet-base gluing by using new magnets and magnet-bases which were prepared day before yesterday.
From the experience of ITMX recovery, we improved targeting way of magnet-base by jigs, and I think it works well.
We spent about 3 hours for this work.
The jigs will be removed Tue.
CRY (Cryo-payload IX)
takayuki.tomaru - 8:16 Tuesday 20 February 2024 (28632) Print this report
ITMX recovery (Magnet re-glue)
Tomaru, Rishabh

We removed magnet-gluie-jigs.
We confirmed the strength of the glued magnet-bases by tweezers.
But we found two problems.
1) Magnet-base positions shifted to upper side about 1mm from the targets. This comes from the machining precision of jigs and cause miss targeting in glue process. But I think we can improve this by the way to glue magnet-bases.
2) Amount of epoxy was too much. I will reduce the amount next time.
VAC (EY)
nobuhiro.kimura - 6:03 Tuesday 20 February 2024 (28631) Print this report
Flange opening work for EYC and EXC

[Kimura and M. Takahashi]

We opend flanges for EYC and EXC for the payload inspection on 19/Feb..

Comments to this report:
nobuhiro.kimura - 20:33 Tuesday 20 February 2024 (28638) Print this report

[Kimura and M. Takahashi]

 This afternoon we opened the two flanges on both sides of the TMSY chamber.
After opening the flanges, we put curing tape to protect the sealing surfaces.

VIS (PR2)
naoatsu.hirata - 22:43 Monday 19 February 2024 (28630) Print this report
Comment to Recovery of PR2 suspension (28593)

[Hirata, Washimi-san, Ikeda-san]

We tried to adjust length Oplev by Traverser. But we didn't finish it.

  • First, Ikeda-san and Washimi-san did cabling and connected 24V power cable for Traverser.
  • We checked and adjusted tilt Oplev.
  • Moved Traverser [x, y]=[-1500um,-1500um] (It's Traverser coodinate system), and IM Yaw pico -3550steps. Tilt Oplev changed more significantly than last week trial. We think Traverser is working now.
  • Length Oplev horizontal value changed from 280(before moving Traverser) to 278.9. It decreased little bit.
  • When we checked IM H2 OSEM, We lost tilt Oplev (again). We recovered it.

Tommorow, after opening chamber top, we will try to measure Traverser position directly.

VIS (PRM)
naoatsu.hirata - 21:37 Monday 19 February 2024 (28626) Print this report
Comment to Recovery of PRM suspension (28380)

[Hirata, Washimi-san, Ikeda-san]

We checked IM OSEM flags.

  • First, we checked IM H2 coil by LCR meter. The value was almost same as acceptance check list.
  • We found IM H2 OSEM flag is touching.
  • H2 OSEM holder is reached to its limit.
  • Aso-san advised us that all OSEM plates should be modified except H1. H1 was already modified.
  • We removed OSEM holders.
  • We realized V2 OSEM holder was already modified(7-D7 screw hole is D10), and we can adjust it to the good position.

OSEM holders will be modified at Mitaka.

  • Lateral OSEM(H2,H3) D7 holes should be long hole to move it more higher position.JGW-D2415637
  • Top OSEM(V1,V3) should be modified as same as V2 (D7 to D10).JGW-D2415636
Images attached to this comment
CAL (General)
hirotaka.yuzurihara - 20:33 Monday 19 February 2024 (28629) Print this report
Comment to Investigation of the issue that the image centers by two cameras were not matched (28571)

I analyzed the taken images and summarized the details in the wiki page(https://dac.icrr.u-tokyo.ac.jp/KAGRA/DAWG/Detchar/klog/klog28571).

Brief report

After I manipulated two images taken by two kinds of cameras, I overlayed two images. I have attached that image. It seems that the center of the images is different. I will investigate the cause deeper next time.

Images attached to this comment
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