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PEM (EY)
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tatsuki.washimi - 15:04, Thursday 03 December 2020 (15587)Get code to link to this report
Comment to Water fluid monitor (Click here to view original report: 15531)

[YokozaWashimi]

Today we bring back the portable fluid meter and measured at many places.

time place channel H V
10:05 Y-end behined (total) W 0.6m 0.03m 0.52m/s
10:13 Y-end behined (chuoh-haisui) W 0.6m 0.03m 1.3m/s
10:37 sp2826 phi 0.4m 0.17m 0.92m/s
10:50 sp2133 phi 0.4m 0.28m 0.52m/s
11:10 sp1011 phi 0.4m 0.07m 0.25m/s
11:40 X-arm bypass door phi 0.5m 0.29m 0.43m
Images attached to this comment
15587_20201203065908_dsc0338.jpg 15587_20201203070028_dsc0339.jpg 15587_20201203070110_dsc0344.jpg 15587_20201203070309_dsc0347.jpg 15587_20201203070358_dsc0349.jpg 15587_20201203070444_dsc0352.jpg
VIS (General)
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satoru.ikeda - 10:03, Thursday 03 December 2020 (15586)Get code to link to this report
Comment to Type-C guardians were prepared (Click here to view original report: 15578)
We have REVERTED the following differences in the SDF of the following optics.
K1VISIMMT2(ALIGNED)
K1VISMCE(SAFE)
K1VISMCI(SAFE)
K1VISMCO(SAFE)
K1VISOSTM(SAFE)
Also changed the tType-C K1:VIS-(optic)_TM_OPTICALIGN_Y{P}_GAIN to 3.0.
Images attached to this comment
15586_20201203020126_k1visimmt2sdftablefrom20201202164252.png 15586_20201203020132_k1vismcesdftablefrom20201202155743.png 15586_20201203020138_k1vismcisdftablefrom20201202154653.png 15586_20201203020149_k1vismcosdftablefrom20201202160627.png 15586_20201203020155_k1visostmsdftablefrom20201202165111.png
Non-image files attached to this comment
CAL (General)
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dan.chen - 06:39, Thursday 03 December 2020 (15584)Get code to link to this report
Pcal laser power noise measurement
Darkhan Tuyenbayev, Dan Chen

2020/12/2

We investigated XPcal noise.

What we found today:
- If we connect D-sub GND(=5th pin) and DC power GND, the noise at excitation and error point decrease by 10dB.
- We found a large sin wave(>1V) at 500kHz at the excitation signal from DGS. (attached picture)
- Even if we connected excitation cable with OFS box, the noise at excitation cable did not change.
- After we connect D-sub GND(=5th pin) and DC grand, the fluctuation of excitation noise became stable.
Images attached to this report
15584_20201202223930_img1852.jpg
VIS (SR2)
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fabian.arellano - 22:14, Wednesday 02 December 2020 (15583)Get code to link to this report
F0 vertical and yaw stepper motor limit switch installation.

Hirata, Yano, Fabian

Related pictures can be found in the album SR2 Remedying work after O3.

The installation of the limit switches for both systems was completed.

  • The cabling diagram is the same as in other SR suspensions and it's reported in the notebook and in the photo album.
  • We tested the switches using the medm screen by pressing the switches manually. They worked well.
  • The ballast mass on top of the F0 keystone was 303 grams.
  • The mass of the old and new yaw stepper motor assemblies are (with cables)
    • New: 758 g
    • Old: 647 g
    • Difference: 111 g
  • We removed 110 g, so the current amount of ballast is 304 grams.
VIS (SR3)
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fabian.arellano - 21:56, Wednesday 02 December 2020 (15582)Get code to link to this report
Comment to F0 vertical and yaw stepper motor limit switch installation. (Click here to view original report: 15541)

With Washimi-san.

See pictures at SR3 Remedying Work after O3.

We installed the support for the F0 FR motor limit switches. The process went smoothly. Because the mechanical support for the cables was not considered in the design, we attached the limit switch cables  to a nearby pillar. No picture of this in SR3 but there's a picture of a similar arrangement in SRM here. We used kapton wire as a cable tie.

We tested the upper switch using Ikeda-san's current script:

  • According to what we know, the polarity of the motor is the correct one for the script to work: positive number of steps moves the FR up (see klog 15272).
  • We turned the switches on in the medm screen by writing 1 in a field next to a button with a letter "D". We pressed the button afterwards (see JGW-T2011520).
  • I moved the upper limit switch down close tot the FR carriage just for the test.
  • The upper switrch is called "Right" in the steper motor driver convention.
  • The script did not detect automatically when the switch had been pressed by the trigger plate, I had to press the corresponding medm update button to check the reaction of the software.

After the test I set up the position of the upper limit at a suitable height. In such a position, the carriage is about 2 mm or 3 mm from the physcal stop nuts. See picture1 and picture2.

VIS (SR3)
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fabian.arellano - 21:55, Wednesday 02 December 2020 (15581)Get code to link to this report
Comment to F0 vertical and yaw stepper motor limit switch installation. (Click here to view original report: 15541)

With Washimi-san.

See pictures at SR3 Remedying Work after O3.

We installed the support for the F0 FR motor limit switches. The process went smoothly. Because the mechanical support for the cables was not considered in the design, we attached the limit switch cables  to a nearby pillar. No picture of this in SR3 but there's a picture of a similar arrangement in SRM here. We used kapton wire as a cable tie.

We tested the upper switch using Ikeda-san's current script:

  • According to what we know, the polarity of the motor is the correct one for the script to work: positive number of steps moves the FR up (see klog ).
  • We turned the switches on in the medm screen by writing 1 in a field next to a button with a letter "D". We pressed the button afterwards (see JGW-T2011520).
  • I moved the upper limit switch down close tot the FR carriage just for the test.
  • The upper switrch is called "Right" in the steper motor driver convention.
  • The script did not detect automatically when the switch had been pressed by the trigger plate, I had to press the corresponding medm update button to check the reaction of the software.

After the test I set up the position of the upper limit at a suitable height. In such a position, the carriage is about 2 mm or 3 mm from the physcal stop nuts. See picture1 and picture2.

VIS (IX)
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ryutaro.takahashi - 20:21, Wednesday 02 December 2020 (15580)Get code to link to this report
Test of modified LVDT card

I tested the LVDT card modified by Tomura-san. The pin #14 of AD630 (demodulator) was grounded for the gain-of-two configulation.

Outputs of the card were compared with the original card using IP channels (H1~H3).

  Original [V] Modified [V]
H1 -0.31 -0.54
H2 0.30 0.58
H3 0.06 0.10

The outputs of modified card were about two times larger than the original card. This result is reasonable.

IOO (IFI)
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keiko.kokeyama - 18:43, Wednesday 02 December 2020 (15579)Get code to link to this report
Comment to Investigation of Ghost beam at IMM/IFI (Click here to view original report: 15568)

Some minor notes:

We connected the picomotor LAN cable back to the MCF pico driver. It is back online.

MC suspensions seemed to jump at ~7am today. (Did we have EQ?) They were recovered using both pico and coil outputs.

VIS (General)
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kouseki.miyo - 18:01, Wednesday 02 December 2020 (15578)Get code to link to this report
Type-C guardians were prepared

Ikeda, Miyo

We (mainly Ikeda-san) made the guardians for Type-C suspensions.

Now, we can align the all Type-C suspensions by using guardian.

After the Type-C guardian development, we confirmed with Nakano-san that IMC was locked after three suspensions for IMC were aligned by Ikeda-san's guardian.

During this work, some differences were accepted in SDF. Ikeda-san will post about it tomorrow.

Comments related to this report
satoru.ikeda - 10:03, Thursday 03 December 2020 (15586)
We have REVERTED the following differences in the SDF of the following optics.
K1VISIMMT2(ALIGNED)
K1VISMCE(SAFE)
K1VISMCI(SAFE)
K1VISMCO(SAFE)
K1VISOSTM(SAFE)
Also changed the tType-C K1:VIS-(optic)_TM_OPTICALIGN_Y{P}_GAIN to 3.0.
IOO (IFI)
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kenta.tanaka - 16:44, Wednesday 02 December 2020 (15577)Get code to link to this report
Comment to Investigation of Ghost beam at IMM/IFI (Click here to view original report: 15568)

Kokeyama, Sato, Nakano(remote), Kenta

Today, We looked into the ghost beams by reflected beam from PRM in IFI chamber. We found the 2 ghosts (rGB1, 16) and the some beams that we don't understand where they come from.

What we did

  • We set the power of input beam 5 W, and aligned PRM, we investigated the ghost beam by reflected beam from PRM based on Tanioka-san's data as yesterday investigation. 
  • As a result, we found two ghost beams (rGB 1, 16). We confirmed that they were indeed the ghost beams from the reflected beam, by blocking the beam reflected from the PRM only.
  • We also found some ghost beams between the MCF and IFI chambers, but we could not determine where they were coming from .
  • I attached a paint that summarizes the ghost beams we've found in our research so far.

Todo

  • investigate where the unknown ghost beams come from again.
  • In particular, we are somewhat concerned about the shape of the transmitted beam from the STM2, so we will re-examine the area around the STM2. In some cases, the STM2 may be replaced.
  • Also, we found that the clamping of some optical instruments is not good, so we re-clamp them.
Non-image files attached to this comment
CRY (Cryo-payload IX)
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takafumi.ushiba - 12:47, Wednesday 02 December 2020 (15576)Get code to link to this report
First contact was applied to the ITMX on both HR and AR surface

[Tomaru, Node, Ushiba]

From yesterday, we applied to the first contact to ITMX.
We set the jigs for first contact application and paint on the ITMX (see pic.1 and pic.2).

Jigs which directly touches the HR and AR surfaces is made of Teflon and coverred by Vectra alpha 10.

After the application, we put the tab for removing first contact and remove the jigs. (see pic.3).

Images attached to this report
15576_20201202044434_img4027.jpg 15576_20201202044439_img4028.jpg 15576_20201202044444_img4029.jpg
CRY (Cryo-payload R&D)
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takafumi.ushiba - 09:45, Wednesday 02 December 2020 (15575)Get code to link to this report
Comment to Actuator efficiency measurement of new magnet (Click here to view original report: 15517)

I measured the force between magnets on MN and cans of PDs in more wider range (see attachment).

We considered to use the other best position for coil-magnet actuator to keep the distance between magnet and PD larger.
However, even if we use the other best position, the force is roughly 5 times smaller but still remains.
So, we need to consider another option.

One possible solution is to separate actuator coils and photosensors (PSs).
Since the cryopayload have many dummy coil bobins to keep their symmetry, it is not so difficult to separate coils and PSs.
Another solusion is to redesign the coil bobins but it will take long time.
So, Ithink it is not suitable for current tough schedule.

Images attached to this comment
15575_20201202014427_actuatorefficiencymeasurement.jpg
CAL (General)
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dan.chen - 06:45, Wednesday 02 December 2020 (15574)Get code to link to this report
Pcal laser power noise measurement
Dan Chen, Darkhan Tuyenbayev

2020/12/1

We investigated noise of XPcal.

We measured noise at error monitor of OFS circuit box. (FFT analyzer has -120dB noise)
Case A: Test IN = short, PD = connected, Excitation = short, Offset = short => -120dB
Case B: Test IN = open, PD = connected, Excitation = short, Offset = connected => -80dB
Case C: Test IN = open, PD = connected, Excitation = connected, Offset = short => -60dB
Case D: Test IN = open, PD = connected, Excitation = connected without ground connection, Offset = short => -60dB
Case E: DGS + 40m cable (Excitation) => -100dB
Case F: DGS + 40m cable (offset) => -120dB
Case G: Test IN = short, PD = connected, Excitation = short, Offset = short, 40m cable housing and cable housing from OFS are connected => -120dB(?)
Case H: Test IN = short, PD = connected, Excitation = short, Offset = short, 40m cable housing and cable housing from OFS are not connected => -120dB(?We need to check this exactly value from the data but the difference from case G was small.)
Case I: Test IN = short, PD = connected, Excitation = short, Offset = short => noise at error monitor point and to AOM point has not so much difference. ~4dB

From these measurements we think:
- Signal from DGS through 40m cable is clean.
- OFS circuit itself is also clean.
- But somehow when it connect, noise goes up.
- It seems ground connection between 40m cable and cable to OFS circuit does not make the noise worse.
- It seems a variable gain just after the error monitor point does not make the noise worse.
IOO (IFI)
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tatsuki.washimi - 22:10, Tuesday 01 December 2020 (15573)Get code to link to this report
Comment to Investigation of Ghost beam at IMM/IFI (Click here to view original report: 15568)

In the hummering test and acoustic injection before/after the O3GK, we found the bellows between IFI and IMC were most effective to DARM but chambers and their legs were not effective.
So I guess the most serious ghost beam was coming back from the down stream to these bellows directly, not hitted any object inside the IFI chamber.

In the picture took from IMM chamber side today, we can see the aluminium hoil directly in the marked space.

Other pictures I took are here.

Images attached to this comment
15573_20201201140927_pic1.png 15573_20201201140938_pic2.png
VIS (BS)
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fabian.arellano - 21:31, Tuesday 01 December 2020 (15572)Get code to link to this report
IP simple work

With Washimi, Hirata, Yano and Iguchi

  • We opened the vacuum chamber to lock the IP for Terrece to take measurements.
  • Once he finished we released the IP.
  • We found the IP LVDT fixing jig.
VIS (SRM)
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fabian.arellano - 21:29, Tuesday 01 December 2020 (15571)Get code to link to this report
Comment to Top Filter stepper motor limit switches installation. (Click here to view original report: 15530)

With Hirata, Yano, Iguchi.

See pictures, including pictures of the notebook,  at SRM Remedying Work album.

  • We received new long M3 screws, tall M3 nuts and small M3 washers to install the support for the F0 FR limit switches.
  • Hirata-san washed them in the morning.
  • About installation:
    • The new screws are inserted from underneath the IP table, hold the cable clamps base underneath the IP and the limit switch support on the top.
    • After installation we clamped back some cables we had unclamped to have access for the screws.
  • We tested the limit switches by moving the carriage of the FR and letting the trigger plate mounted in the carriage press the swtich.
    • The plate triggers the lower switch without problems. (We didn't test the upper one).
    • However, the medm required manually updating the stepper motor information to show the switch had been pressed. This is likely related to the polarity of the motor, which we have not changed yet.
  • Following Satou-san's instructions we swapped the switches in the F0 yaw motor. The new cabling diagram can be found in this picture of the notebook.

TO DO list

  • Change the polarity of the F0 FR stepper motor. Find out and report here which pins to exchange. We'll use this information more than once.
  • Check whether we can change the speed of the motor from Ikeda-san's medm screen and increase the speed. Otherwise use Shoda-san's medm screen.
  • Test the whole range of the motor with the limit switches.
VIS (BS)
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kouseki.miyo - 20:09, Tuesday 01 December 2020 (15570)Get code to link to this report
Comment to Strange channel swap and digital system error (Click here to view original report: 15567)

Terrence, sorry I restarted the all models for RT-model updating. The AWG trouble could be happen by this work.
Anyway, could you confirm that there are no error by looking the VIS_OVERVIEW screen before starting your measurements?

Now, I and Yamamoto-san fixed that problems after the restarting. Now all green.

Images attached to this comment
15570_20201201120820_screenshotfrom20201201200745.png
IOO (IFI)
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kenta.tanaka - 19:01, Tuesday 01 December 2020 (15568)Get code to link to this report
Investigation of Ghost beam at IMM/IFI

Kokeyama, Sato, Washimi, Nakano(remote), Kenta

According to Tanioka-san's simulation, We investigated the ghost beams in IFI chamber by input beam from IMC.  We found 4 ghosts (iGB1,3,5,17) but could not find the others in the simulation

What we did

  •  First, we set the power of the input beam from IMC 0.1 W and found the ghost beam around IFI according the list of the ghost beams simulated by Tanioka-san. we could not find them.
  • Then, we increased the power to 0.3 W, we found 4 beams (iGB1,3,5,17). Here are the pictures of the ghost beams when the input beam is at 5W power.
  • Finally, we increased the power to 1 → 3 → 5 W, except for the four beams above, we could not find.

To do 

  • Increase the power of the input beam to 10 W and search again.
  • Search for the ghost beams by beam coming back from the PRM
Images attached to this report
15568_20201201110044_img0646.png 15568_20201201110059_img0642.png 15568_20201201110113_img0643.png 15568_20201201110126_img0647.png
Comments related to this report
keiko.kokeyama - 18:43, Wednesday 02 December 2020 (15579)

Some minor notes:

We connected the picomotor LAN cable back to the MCF pico driver. It is back online.

MC suspensions seemed to jump at ~7am today. (Did we have EQ?) They were recovered using both pico and coil outputs.

tatsuki.washimi - 22:10, Tuesday 01 December 2020 (15573)

In the hummering test and acoustic injection before/after the O3GK, we found the bellows between IFI and IMC were most effective to DARM but chambers and their legs were not effective.
So I guess the most serious ghost beam was coming back from the down stream to these bellows directly, not hitted any object inside the IFI chamber.

In the picture took from IMM chamber side today, we can see the aluminium hoil directly in the marked space.

Other pictures I took are here.

kenta.tanaka - 16:44, Wednesday 02 December 2020 (15577)

Kokeyama, Sato, Nakano(remote), Kenta

Today, We looked into the ghost beams by reflected beam from PRM in IFI chamber. We found the 2 ghosts (rGB1, 16) and the some beams that we don't understand where they come from.

What we did

  • We set the power of input beam 5 W, and aligned PRM, we investigated the ghost beam by reflected beam from PRM based on Tanioka-san's data as yesterday investigation. 
  • As a result, we found two ghost beams (rGB 1, 16). We confirmed that they were indeed the ghost beams from the reflected beam, by blocking the beam reflected from the PRM only.
  • We also found some ghost beams between the MCF and IFI chambers, but we could not determine where they were coming from .
  • I attached a paint that summarizes the ghost beams we've found in our research so far.

Todo

  • investigate where the unknown ghost beams come from again.
  • In particular, we are somewhat concerned about the shape of the transmitted beam from the STM2, so we will re-examine the area around the STM2. In some cases, the STM2 may be replaced.
  • Also, we found that the clamping of some optical instruments is not good, so we re-clamp them.
VIS (BS)
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takahiro.yamamoto - 18:28, Tuesday 01 December 2020 (15569)Get code to link to this report
Comment to Strange channel swap and digital system error (Click here to view original report: 15567)
It was probably caused by an AWG error.

When the AWG bit shows red, TP and EXC channels cannot be reliable at all.
We need to check at least guardian, SDF, and STATEWORD before starting any measurement for reliable measurements.
VIS (BS)
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terrence.tsang - 17:49, Tuesday 01 December 2020 (15567)Get code to link to this report
Strange channel swap and digital system error

I am running out of ideas so I am just posting this and hope that the power of collective thinking can solve this mystery before I have a chance to anything else.

I wanted to measure properly the sensor noise of the sensors at the inverted pendulum stage so I asked Fabian to lock the IP. I proceeded to measure the sensor readout, together with the sensor correction signal as a reference of the current seismic activity level.

Attached future shows the measurements I obtained. It looks fine and like what I wanted to measure at first glance. However, taking a closer look, something's strange. The legend says that the yellow line is the sensor correction signal while the cyan is the LVDT H3 signal. However, from the plot itself, the yellow looks like the LVDT noise while the cyan looks like a sensor correction signal. Judging from the MEDM screen, I don't think there's internal wrong connections either in the hardware as well as the real-time model. My hypothesis is that there's a bug in the new software that we are using as this is the only variable. I could well be wrong. I don't know what's causing the swap and I am afraid to use the measurements because I don't know if any other measurements are occasionally swapped as well.

I couldn't test it now because some DGS error is preventing me from taking measurements from the BS. This is a separate issue. It seems that I cannot measure the SRM as well. I attached another figure which shows the error I encountered in the diaggui as well as the red indicators in the CDS screen.

Please tell me if I have done anything stupid to put myself into this situation, or if you know what's wrong. Thanks.

Images attached to this report
15567_20201201091444_bsstrangechannelswap20201201.png 15567_20201201094922_bsdgserror20201201.png
Comments related to this report
takahiro.yamamoto - 18:28, Tuesday 01 December 2020 (15569)
It was probably caused by an AWG error.

When the AWG bit shows red, TP and EXC channels cannot be reliable at all.
We need to check at least guardian, SDF, and STATEWORD before starting any measurement for reliable measurements.
kouseki.miyo - 20:09, Tuesday 01 December 2020 (15570)

Terrence, sorry I restarted the all models for RT-model updating. The AWG trouble could be happen by this work.
Anyway, could you confirm that there are no error by looking the VIS_OVERVIEW screen before starting your measurements?

Now, I and Yamamoto-san fixed that problems after the restarting. Now all green.