Participants : Y. Aso, M. Eisenmann, M. Otsuka, B. Park, S. Singh, H. Wang, K. Yamamoto

Agenda :

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

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)

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

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

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

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

Wednesday 23rd 2025 16h JST

KAGRA/Subgroups/MIR/Meetings/Minutes20250409 (last edited 2025-04-22 11:42:49 by marc.eisenmann)