Participants : Y. Aso, M. Eisenmann, M. Otsuka, B. Park, S. Singh, H. Wang, K. Yamamoto
Agenda :
- FY2025 activities
- ITMs preparation
- Polishing :
Wedge correction on-going at Okamoto (up to ~4/25) Nikon to do fine polishing up to end of March 2026 In total about 3 months delay + contract update on-going
- Coating choice :
question is with or without Ti doping (LMA can do both) initial schedule was to send crystal to LMA around February 2026 updated schedule : skip Q measurement (lack of person-power + high risk activity + low-Q likely due to bonding etc..) final schedule depends on polishing schedule + LIGO coating delay but likely 3 months delay aswell (coated ITMs delivered around end of August 2026)
- Bonding preparation
check of cleanroom cleanliness on-going Miyoki-san approved to lend KAGRA's HQ particle counter now delivered at Toyama U. cleaning planned up to ~ May 2025
- Q measurement :
Sato-san left Toyama U. after completing Master thesis Watanabe-san stays at Toyama U. for Master and will work on Q measurement at room temperature
priority of cryo group is sapphire Q not bulk Q
- Birefringence measurement :
paper accepted now measuring sapphire at 1064nm at NAOJ trial sapphire measurement at 2um at UWA LMA might be able to measure TWE of sapphire to reconstruct birefringence
- Absorption measurement :
calibration of PCI at KASI on-going planned calibrated samples exchange should be able to measure up to 100kg and could upgrade to 1550 and 2000nm
- Next meeting :
Wednesday 23rd 2025 16h JST