Memo for Commissioning break (Mar. 2020)

- 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.

Task list (Partially done)

• 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

Task list (todo ; must items)

• Hammering test around BS chamber
  • Possible noise source 70-100Hz
  • Identification the noise path
    • From leg? From oplev? From duct?
  • Set accelerometer for feed-forward
• Hammering test of the PR2, PR3, PRM, IMMT2 chamber
  • We didn't get any information from those chambers
• 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
  • Identification of the noise path
• 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
  • Identification of the noise path
• 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
  • (Must) IMC REFL table, REFL table, POP table
  • (Should) POS table, TMSX table, TMSY table

  • (If possible) OpLev tables, PCal tables

Task list (todo ; if possible)

- PEM injection

Task list (Done)

• Vibration injection to OMC leg for optical table

  • klog13152

  • We confirmed that the vibration from OMC leg is under the sensitivity curve

Task list (todo ; must items)