OMC Closing Review (2022/11/18)

• OMC (Aso, NAOJ)

  • Higher mode rejection -> OK with good mode matching.

  • New optical board to remove additional structure for resonance dumping.

  • New high-quality mirror. -> 97% T_FP.

  • Replacement of the broken PD

  • 800 Hz resonance still remains. -> unstable lock in air. Pumping down OMC are will mitigate this resonance.

    • FP_tra estimation in air ~ 0.89 derived by subtracting HOMs power sum from the total power.

• OMMT1, OMMT2, OSTM Suspension (Takahasi, NAOJ)

  • Transfer Function
  • OSEM output values
  • Space btw magnets and plates
  • Pico motion

• Installation Acceptance Document for modified sub-optics in the OMM and OMC chambers (Akutstu, NAOJ)

  • klog#22934

  • klog#22942

• OMMT2T optical setting for sensing OMMT1/SR2 motion separately (Ushiba, Akutsu, Miyoki, Sato, Takahashi)

  • klog#22604

  • klog#22611

  • klog#22844

  • klog#22848

  • klog#22946

  • Final alignment and Iris removal.
  • Reliable cover using aluminum foils.
• Vacuum Issues

  • Clamp preparation -> OK, f300 -> metal, f800 -> elastomer,

  • TMP/IP alignment OMC-OMMT-TMIPunit.pdf

  • Trouble in a -Y side Hatch

  • Opened viewports confirmation
  • Cleaning inside
  • Leak in GV_srm-OMM again??

  • Slow pumping as IFI-IMMT/IMC -> Suspension Monitoring(Takahashi-san + alpha)