Differences between revisions 2 and 5 (spanning 3 versions)
Revision 2 as of 2024-02-02 17:02:05
Size: 826
Comment:
Revision 5 as of 2024-05-08 18:37:50
Size: 2457
Comment:
Deletions are marked like this. Additions are marked like this.
Line 3: Line 3:
Participants : Marc Eisenmann, Shalika Singh, Haoyu Wang, Kazuhiro Yamamoto Participants : Yoichi Aso, Marc Eisenmann, Kazuhiro Yamamoto, Haoyu Wang
Line 7: Line 7:
  * update on ITM polishing status
  * Q-measurement on-site/off-site
  * coating loss measurement
  * updates on papers

Minutes :
  * birefringence from TWE paper in circulation among co-authors
  * birefringence compensation paper in circulation among co-authors
  * report on thermal noise presentation during O5 task force :
    * no issue for thermal noise if loss are concentrated
  * new loss measurement from NAOJ coating (done by Waseda-san) :
    * does not show temperature dependence
    * similar level as KAGRA design
    * more measurements on-going

Next meeting : share a poll to see if there is convenient date to have more attendees
* update on ITM polishing status (Aso)
    * acceptance check at Okamoto today
    * scratches visibles on surfaces (< 1um) and few (<5um) : should be removable by Nikon as they will remove about .5mm thickness
    * visit at Nikon on Monday to proceed for polishing
    * small chip (not crack) about 0.5-1 mm in size close to barrel side on AR side. Found after removing a protective film recently. Should not affect thermal noise
    * coating should be decided at maximum in about 1 year from now and should last about 1 month
* Q-measurement on-site/off-site (Yamamoto)
    * performed up to December and results uploaded in JGWDOC. planned to continue when possible
    * try to invite other involved people for next meeting
* ET pathfinder visit (Yamamoto)
    * most vacuum chambers are ready. 2 TM (15cm diameter/8cm thickness) are ready but polishing was complicated
    * may AEI Hannover group performed characterization
* coating loss measurement (Yamamoto)
    * paper accepted in PRD. Will also be presented at GWADW2024
* birefringence measurements (Marc)
    * able to reconstruct Jones matrix, diattenuation and retardation in transmission and reflection. More updates by Shalika next meeting. Presented at GWADW2024
    * could be interesting to measure Toyama coating sample to test Jones matrix theory of such coating * sapphire spectroscopy
* updates on papers (Haoyu, Marc)
    * birefringence compensation paper accepted in Optics Letters. Presented at GWADW2024
    * birefringence from TWE planned to publish in PRD. Playground data was accepted so it will be short author list. Partially presented at GWADW2024
* sapphire's spectroscopy (Marc)
    * Try to compare PCI absorption at 1064 nm with reconstruction from spectroscopy. Promising results but need to refine the analysis. acquired ICRR inter-university funding to support this activity. would like to use FRIT spectrometer but not available at NAOJ.
* ITM polishing strategy (Haoyu)
    * IBF used to minimize alpha_+ could lead to offset in P polarized light (visible in current ITMs). But IBF will only remove um of material so will have negligeable effect on alpha_-
* Next meeting :
     * on the week of June 3rd. share a poll to see if there is convenient date to have more attendees

MIR meeting on Wednesday January 24th, 2024 16:00-17:00 JST

Participants : Yoichi Aso, Marc Eisenmann, Kazuhiro Yamamoto, Haoyu Wang

Agenda :

* update on ITM polishing status (Aso)

  • acceptance check at Okamoto today
  • scratches visibles on surfaces (< 1um) and few (<5um) : should be removable by Nikon as they will remove about .5mm thickness

  • visit at Nikon on Monday to proceed for polishing
  • small chip (not crack) about 0.5-1 mm in size close to barrel side on AR side. Found after removing a protective film recently. Should not affect thermal noise
  • coating should be decided at maximum in about 1 year from now and should last about 1 month

* Q-measurement on-site/off-site (Yamamoto)

  • performed up to December and results uploaded in JGWDOC. planned to continue when possible
  • try to invite other involved people for next meeting

* ET pathfinder visit (Yamamoto)

  • most vacuum chambers are ready. 2 TM (15cm diameter/8cm thickness) are ready but polishing was complicated
  • may AEI Hannover group performed characterization

* coating loss measurement (Yamamoto)

  • paper accepted in PRD. Will also be presented at GWADW2024

* birefringence measurements (Marc)

  • able to reconstruct Jones matrix, diattenuation and retardation in transmission and reflection. More updates by Shalika next meeting. Presented at GWADW2024
  • could be interesting to measure Toyama coating sample to test Jones matrix theory of such coating * sapphire spectroscopy

* updates on papers (Haoyu, Marc)

  • birefringence compensation paper accepted in Optics Letters. Presented at GWADW2024
  • birefringence from TWE planned to publish in PRD. Playground data was accepted so it will be short author list. Partially presented at GWADW2024

* sapphire's spectroscopy (Marc)

  • Try to compare PCI absorption at 1064 nm with reconstruction from spectroscopy. Promising results but need to refine the analysis. acquired ICRR inter-university funding to support this activity. would like to use FRIT spectrometer but not available at NAOJ.

* ITM polishing strategy (Haoyu)

  • IBF used to minimize alpha_+ could lead to offset in P polarized light (visible in current ITMs). But IBF will only remove um of material so will have negligeable effect on alpha_-

* Next meeting :

  • on the week of June 3rd. share a poll to see if there is convenient date to have more attendees

KAGRA/Subgroups/MIR/Meetings/Minutes20240124 (last edited 2024-05-08 18:37:50 by marc.eisenmann)