Differences between revisions 4 and 26 (spanning 22 versions)
⇤ ← Revision 4 as of 2022-11-18 12:03:52 →
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Editor: miyoki
Comment:
← Revision 26 as of 2022-11-18 16:10:45 → ⇥
Size: 3707
Editor: miyoki
Comment:
Deletions are marked like this. Additions are marked like this.
Line 5: Line 5:
 * OMC (Aso-kun, NAOJ)
  *		  * [[ https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=14515 | OMC (Aso, NAOJ)]]
  * Higher mode rejection -> OK with good mode matching. -> will be checked after pumping.
  * 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.
  * OMC alignment. OSTM should not be moved by pico to avoid trouble.
  * Dark noise: same btw both PDs.
  * OFI performance check to investigate mysterious power loss (60% !!). -> Good enough! No problem.
Line 8: Line 16:
 * OMMT1, OMMT2, OSTM Suspension (Takahasi-san, NAOJ)   * PD protector: Fast beam shutter(we don't have) or PZT offset to unlock the OMC. -> Urgent issue. 50mW/one PD is acceptable.

  * Update plan to improve PD circuit for the in-air lock?
  * Notch filter cannot help to avoid resonance -> 800Hz is in the obs band!! Another circuit for the in-air work?
  * Why DC-PD was broken? -> It was damaged during removing the glass window. A high-quality can opener is necessary. A can opener of Thorlabs that has a shaper edge.
  * Quantum Efficiency of PD ~ 9? %. No actual measurement. Uncertainty is large. Measure the QE of a spare PD?
  * The calibration factor is included in MEDM.


 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=14522 | OMMT1, OMMT2, OSTM Suspension (Takahashi, NAOJ)]]
Line 10: Line 27:
  * OSEM Values    * OSTM has a different TF(LPY) compared with OMMT1/2 because it has a thinner TM.
   * OSEM output values vary with each other. Coupling force variation. -> LPY coupling will be generated. Maybe acceptable because we don't use them for control.
  * Space btw magnets and plates
   * Took photos. All gaps are OK.
  * Pico motion
 
  * TF of H1~4 phases are OK? Actuation signs (directions) are managed well? -> OSTM has different of magnets S-N direction after magnet repair.
   * Positive -> push? Should be confirmed.
   * Push -> OSEM voltage should be negative.
Line 12: Line 37:
 * Stray light dumping (Akutstu-kun, NAOJ)  * [[ https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=14523 | Installation Acceptance Document for modified sub-optics in the OMM and OMC chambers (Akutstu, NAOJ) ]]
Line 14: Line 39:
  * [[ https://klog.icrr.u-tokyo.ac.jp/osl/?r=22942 | klog#22942 ]]   * [[https://klog.icrr.u-tokyo.ac.jp/osl/?r=22942 | klog#22942 ]]
Line 16: Line 41:
 * OMMT2T optical setting (Ushiba, Akutsu, Miyoki, Sato)   * Dumper 1 cannot kill the beam because it was shielded by wiring. No time to make a proper dumper for it. It could be between O4ab.
   * The cable cannot be removed!! A solution dose exist?? A black plate or a mirror can help??

 * OMMT2T optical setting for sensing OMMT1/SR2 motion separately (Ushiba, Akutsu, Miyoki, Sato, Takahashi)
Line 26: Line 54:
  * TMP/IP alignment
  * Trouble in a -Y side Hatch		   * Clamp preparation -> OK, f300 -> metal, f800 -> elastomer,
  * TMP/IP alignment [[attachment:OMC-OMMT-TMIPunit.pdf]]
  * [[https://klog.icrr.u-tokyo.ac.jp/osl/?r=22948 | Trouble in a -Y side Hatch]]
Line 30: Line 59:
  * Leak in GV again??   * Leak in GV_srm-OMM again??
  * Slow pumping as IFI-IMMT/IMC -> Suspension Monitoring(Takahashi-san + alpha)

OMC Closing Review (2022/11/18)

  • OMC (Aso, NAOJ)

    • Higher mode rejection -> OK with good mode matching. -> will be checked after pumping.

    • 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.
    • OMC alignment. OSTM should not be moved by pico to avoid trouble.
    • Dark noise: same btw both PDs.

    • OFI performance check to investigate mysterious power loss (60% !!). -> Good enough! No problem.

    • PD protector: Fast beam shutter(we don't have) or PZT offset to unlock the OMC. -> Urgent issue. 50mW/one PD is acceptable.

    • Update plan to improve PD circuit for the in-air lock?

    • Notch filter cannot help to avoid resonance -> 800Hz is in the obs band!! Another circuit for the in-air work?

    • Why DC-PD was broken? -> It was damaged during removing the glass window. A high-quality can opener is necessary. A can opener of Thorlabs that has a shaper edge.

    • Quantum Efficiency of PD ~ 9? %. No actual measurement. Uncertainty is large. Measure the QE of a spare PD?
    • The calibration factor is included in MEDM.

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

    • Transfer Function
      • OSTM has a different TF(LPY) compared with OMMT1/2 because it has a thinner TM.

      • OSEM output values vary with each other. Coupling force variation. -> LPY coupling will be generated. Maybe acceptable because we don't use them for control.

    • Space btw magnets and plates
      • Took photos. All gaps are OK.
    • Pico motion

    • TF of H1~4 phases are OK? Actuation signs (directions) are managed well? -> OSTM has different of magnets S-N direction after magnet repair.

      • Positive -> push? Should be confirmed.

      • Push -> OSEM voltage should be negative.

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

    • klog#22934

    • klog#22942

    • Dumper 1 cannot kill the beam because it was shielded by wiring. No time to make a proper dumper for it. It could be between O4ab.
      • The cable cannot be removed!! A solution dose exist?? A black plate or a mirror can help??
  • OMMT2T optical setting for sensing OMMT1/SR2 motion separately (Ushiba, Akutsu, Miyoki, Sato, Takahashi)
  • 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)

KAGRA/IFOIntegration2022/2022OMCClosing (last edited 2022-11-19 09:32:06 by miyoki)