Differences between revisions 4 and 5

MIR Meeting on 2023/07/05 15:00 - 16:00

Participants: KYamamoto, June-Gyu, Marc, Sungho, Aso, Matteo

2023 ?? ??, 1?:00 - 1?:00

Minutes

Paper on coating (Mori, Nakayama): Ti doped (LIGO) and undoped (KAGRA) SiO2-Tantala stacks
- coating thermal noise seems higher than expected value
- internal review by coauthors being done at the moment
- will be circulated to MIR subgroup in the next weeks
Planned presentation of the measurements contained in the paper at the next LVK
Measurement of Q-value for KAGRA sapphire mirrors
- CARM-DARM as readout sensors, magnets as actuators
- T= 80K for ETMX and T=250K for all the others
- all Q value are between 1e4 to 1e5, seems low compared to expected value of 1e8
- investigation of the reason of low Q ongoing, dissipation source is not clear
- offline test on spare ETMs could be done to investigate the source of dissipation (Aso)
report on polishing of new ITMs by Aso
- Shaping, lateral flats and barrel done by ARD
- pre-polishing and wedge will be done by Okamoto Optics (test polishing done successfully)
- lead time of pre-polishing is largely increased due to necessity to avoid subsurface damage

KAGRA/Subgroups/MIR/Meetings/Minutes20230705 (last edited 2023-07-05 16:33:02 by matteo.leonardi)

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+  * investigation of the reason of low Q ongoing, dissipation source is not clear
  * offline test on spare ETMs could be done to investigate the source of dissipation (Aso)
 1. report on polishing of new ITMs by Aso
  * Shaping, lateral flats and barrel done by ARD
  * pre-polishing and wedge will be done by Okamoto Optics (test polishing done successfully)
  * lead time of pre-polishing is largely increased due to necessity to avoid subsurface damage