Memo for Commissioning break (Mar. 2020)

• Summary result of the acoustic injection here

Priority of task

• Hammering test of the cryochamber
  • If Tomaru-san or Ushiba-san help

- Hammering test

Task list (Done)

• Hammering test of the OMC chamber (Done 22nd Feb.)

  • klog13105

  • There is excess in the sensitivity between 100 Hz to 400 Hz
  • Reported later, the main reason is the vibration to the OMC legs for the optical table inside the vacuum
• Hammering test AS table (Done 22nd Feb.)

  • klog13105

  • Reported later, the main reason is the vibration to the OMC legs for the optical table inside the vacuum
• Reflection light check (Done 22nd Feb.)

  • klog13105

  • Now we didn't use the AS PD signals for interferometer control
  • There was possibility that the reflection light from AS table make dirty scattering light
  • Shadowed between the OMC viewport and AS table, but we couldn't see the clear noise reduction
  • Also, when we added vibration to the OMC viewport, we couldn't detect the noise increasing.
• Hammering test SRM chamber (Done 22nd Feb.)

  • klog13105

  • The SRM mirror is misaligned. So We need to investigate the scattering light from SRM mirror
  • In this test, we can see the excess above 100 Hz
  • After this test, we cannot lock the interferometer. So if we have a time, we want to check again.
• Hammering test between PR2 and BS, PR2 side (Done 24th Feb.)

  • klog13138

  • PR2-BS duct give excess noise around 70-100 Hz
• Hammering test between PR2 and BS, PR2 side (Done 24th Feb.)

  • klog13138

  • PR2-BS duct give excess noise around 70-100 Hz
• Hammering test between BS and SR2, BS side (Done 24th Feb.)

  • klog13138

  • BS-SR2 duct give slight excess noise but not much
• Hammering test between BS and SR2, SR2 side (Done 24th Feb.)

  • klog13138

  • BS-SR2 duct give slight excess noise but not much
• Hammering test between SR2 and SR3, SR2 side (Done 24th Feb.)

  • klog13138

  • SR2-SR3 duct give broadband exces noise around 100-400 Hz
• Hammering test between SR2 and SR3, SR3 side (Done 24th Feb.)

  • klog13138

  • SR2-SR3 duct give broadband exces noise around 100-400 Hz
• Hammering test between SR3 and SRM, SR3 side (Done 24th Feb.)

  • klog13138

• Hammering test around BS chamber
  • When hammering the bellows between PR2 and BS, 70-100Hz was excited. Scattered noise?
    • It seems from duct
  • Set accelerometer for feed-forward
    • But, we couldn't see in the spectrum of the portable ACC.
• Hammering test of the PR2, PR3, PRM, IMMT2 chamber
  • Finally, we found that vibration around the IMC gate valve is the path to DARM displacement.
  • Most suspect noise path is scattered light from AR MCO reflected around gate valve and back to main laser.
  • Reducing the vibration.
• Hammering test of the IMMT1 chamber
  • This chamber is including the ISS system
  • We performed the acoustic injection and identified the some noise peaks.
  • We placed the accelerometer on the leg of the IMMT1 chamber
  • No significant result was obtained
• Hammering test of the MCF chamber
  • We performed the acoustic injection and identified the some noise peaks.
  • We placed the accelerometer on the leg of the IMMT1 chamber
  • We had several noise increasing, Washimi-san investigate now.
  • We also do hammering test to the PSL window
• Hammering test of the optical tables
  • (Must) IMC REFL table, REFL table, POP table, ISS table
  • (Should) POS table

  • (If possible) OpLev tables (PR area)

  • We can find 500Hz noise may come from the REFL table

Task list (todo ; must items)

• Hammering test of the cryochamber

  • Discussion

• Hammering test of the ducts
  • To check the scattered light effect, we want to perform the hammering test to the all ducts
  • We will ask Akutsu-san and Aso-san for the priority for following test
• Hammering test of the optical tables
  • (Should) TMSX table, TMSY table
  • (If possible) PCal tables

Task list (todo ; if possible)

• Hammering test of the IXA and IYA chamber
  • Non black coating materials
• Hammering test of the end station
  • EXC, EYC, EXA, EYA chambers
  • TMSX, TMSY chamber

- PEM injection

Task list (Done)

• Vibration injection to OMC legs

  • klog13152

  • We confirmed that the vibration of the OMC leg is under the sensitivity curve
• Acoustic injection to the PSL room(29th Feb.)
  • We couldn't find the any excess
• Acoustic injection to REFL table(29th Feb., 5th Mar. 7th Mar.)

  • klog13231, klog13338, klog13382

  • From klog13382, we can see the some excesses 100-600Hz

  • Washimi-san and TTanaka-san are analyzing data now.
• Acoustic injection to the POP table (11th Mar.)

  • klog13458

  • Large excess 320-400Hz (Related ISS? new noise candidate?)
• Acoustic injection to the cryochamber
  • Done to IXC. Effect would be small.

Task list (todo ; must items)

• Vibration injection to legs of the chambers
  • We did for MCF and IMM legs, but we can ignore the vibration
  • We set the oscillator and accelerometer to OMC leg again

Task list (todo ; if possible)

• Magnetic injection

- Other task by PEM(?)

Task list (done)

Task list (todo)

• Check and remove the unused cables
• Clean up on the optical table
• Check and turn off the unnecessary instrument
• Turn off the some lights
• Clean up the experimental area
  • Clean environment may make the clean experiment