In-vac PD/QPD layout meeting 2024/11/20

Time: Nov 20, 2024 10:00-10:30

Participants: Ray-Kuang Lee, Huali Chen, Yoichi Aso, Yuta Michimura

Zoom meeting

Minutes

• Huali showed the layout idea for AS RF.

  • Enclosure size for RF QPDs were different. Needs to be updated. RF QPD enclosure size is in LIGO-D1102002.

  • Need to include OMC REFL RF QPDs as well.
  • In our case, we don't need to care about the Gouy phase separation between steering mirrors
• Beam height
  • RF QPD height is 4 inch, but the beam height in the OMC chamber is 210 mm.

    • See JGW-D1909819

  • Put a periscope to lower the beam height?
• Put optics on a breadboard to make maintenance/test easier (make it easier to remove and re-install OSTM)
  • Do we also need to have QPDs on the breadboard or not?
  • If QPDs are on the breadboard, we also have to remove the cables for QPDs when moving the breadboard.
• Steering mirrors for RF QPDs: One PZT and one picomotor for QPD centering needed

• A/I

  • Update the layout to include OMC REFL RF QPDs [Huali]
  • Send Huali the part numbers for in-vac steering mirror mounts [Yuta]

    • 2-inch ones in OMC chamber are Sigma-Koki VMHG-50.8. See, also JGW-D1503916

  • Update JGW-T2416178. OMC REFL QPD should be RF, not DC. [Yuta]

    • DONE on Jan 7, 2025
• Next meeting: in the week of Jan 20, 2025
  • Decided to Jan 23, 2025 14:00-15:00 (JST)