In-vac PD/QPD layout meeting 2025/09/12
Time: September 12, 2025 14:15-15:15
Participants: Huali Chen, Ryan Yang, Ray-Kuang Lee, Yoichi Aso, Yuta Michimura
Zoom meeting
Minutes
- POP design (Ryan)
- Redesigned the layout based on q-parameters qx and qy estimated from the green beam.
- But need to be double-checked with Aso-san's Main interferometer parameters.
- OMC chamber (Ryan)
- Updated to add RF QPD base plates, periscopes (now too big), beam diverter, and fast beam shutter (OFI moved by 40.299 mm in +Y direction).
- In-vac periscope (Ryan)
- Did the resonant frequency analysis of the first design using Inventor FEM.
https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=16873
- Fixed-height periscope and adjustable-height periscope had similar resonant frequencies, which seems to be strange.
- It could be due to the complex structure of the periscope (mirror mounts, screws)
- It would be better first to check the resonant frequencies parts by parts.
- Due to limited space, let's design a periscope with 2 inch mirrors fixed plates fixed on a rectangular structure.
- Did the resonant frequency analysis of the first design using Inventor FEM.
A/I
- Consult with VAC people to start designing REFL/POP PD tank [Yuta]
- Design a new periscope with 2 inch mirrors fixed on plates (not mirror mounts) on a rectangular structure. [Ryan]
- Check the resonant frequencies with FEM [Ryan]
- Update POP layout based on q-parameters from Aso-san [Ryan]
- POP at PR2 AR is qx=-1.1801+0.02671i, qy=-1.1812+0.02674i
- POP forward at PR2 AR is qx=-6.7646+0.80946i, qy=-6.7780+0.81116i
- Add in-air green, POP and POP forward layout [Ryan]
- Create cable list (RF QPDs, picomotors, PZTs, beam shutter, beam diverter) for OMC chamber to see their weight for designing OMC vibration isolation table [Yuta; by the end of September?]
- Next meeting: TBD