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2020/6/19 14:00 -  2020/6/19 14:00 -
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Participants:  Participants:
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 * For SR baffle installation:
  * I checked the mirror height reference marks done by Terada-san. They are still there. See klog report [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=14573|14573]].
  * I pointed out the bouyancy correction for the suspended optical bench inside the chamber calculated for our O3: 41 um (klog y [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=8071|8071]]).
 * SR2 decay times: following the issue of the mode IP-L 406 mHz, whose damping time was 35 seconds longer with the control system on (klog entry [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=14510|14510]])
  * I checked the UGF to be 85 mHz (klog entry [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=14550|14550]]). Being lower than 406 mHz it should not have an affect according to certain expectations. The OLTF gain at such frequency was 0.22. Still, I put a notch (f=406 mHz, Q=10 and depth 40 dB) in the filter and repeated the measurement. '''The decay time with the control on decreased by 40 seconds'''.It became 5 seconds shorter than with the control off. See klog entry [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=14574|14574]].
  * The mystery then becomes the mode IP-L at 671 mHz, which is above the UGF and yet the decay time with the control on is 81 seconds shorter than with the control off. In principle the control system shouldn't be doing anything. I will add an notch at 671 mHz just to check the effect.
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 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=11758|Proposal on suspension commissioning]] was shown in the extended chief meeting.
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 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=11475|Revised schedule towards O4]].
* [[https://www.dropbox.com/s/60oygtwmckmdyj6/Towards%20O4%20on%20VIS%20.xlsx?dl=0|Revised task list towards O4]].
 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=11475|Schedule towards O4]] was revised again.
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cf. Post Obs. task ([[https://docs.google.com/spreadsheets/d/1w4q8OvX9E6nkYSgshLYLoZH5yvQXHvGmL1agux8ztx0/edit?usp=sharing|Request]]), Task for O3c ([[https://paper.dropbox.com/doc/Plan-for-the-long-OR-brake--AxxlJFvK1IGJjqrG5nfdHfGXAQ-KqexeqMaCA7DITFGxA5ih|Plan]], [[https://www.dropbox.com/s/hoadb73fdyah02c/Post-O3%20task.xlsx?dl=0|Sheet]]). cf. Post Obs. task ([[https://docs.google.com/spreadsheets/d/1w4q8OvX9E6nkYSgshLYLoZH5yvQXHvGmL1agux8ztx0/edit?usp=sharing|Request]]), Task for O3c ([[https://paper.dropbox.com/doc/Plan-for-the-long-OR-brake--AxxlJFvK1IGJjqrG5nfdHfGXAQ-KqexeqMaCA7DITFGxA5ih|Plan]], [[https://www.dropbox.com/s/hoadb73fdyah02c/Post-O3%20task.xlsx?dl=0|Sheet]]), Task towards O4 ([[https://www.dropbox.com/s/60oygtwmckmdyj6/Towards%20O4%20on%20VIS%20.xlsx?dl=0|List]]).
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 * Correction of concerned topics for the evaluation meeting on 22nd ([[https://docs.google.com/spreadsheets/d/1H4C5fgKQeo33BWILQqFjU4gUUmzLn7y2AYuI5B8rGiA/edit?usp=sharing|google spreadsheet]]).

Agenda/Minutes of the VIS Meeting on 2020/6/19

2020/6/19 14:00 -

Zoom Meeting

Participants:

Progress report

General

Type-A

Type-B

  • For SR baffle installation:
    • I checked the mirror height reference marks done by Terada-san. They are still there. See klog report 14573.

    • I pointed out the bouyancy correction for the suspended optical bench inside the chamber calculated for our O3: 41 um (klog y 8071).

  • SR2 decay times: following the issue of the mode IP-L 406 mHz, whose damping time was 35 seconds longer with the control system on (klog entry 14510)

    • I checked the UGF to be 85 mHz (klog entry 14550). Being lower than 406 mHz it should not have an affect according to certain expectations. The OLTF gain at such frequency was 0.22. Still, I put a notch (f=406 mHz, Q=10 and depth 40 dB) in the filter and repeated the measurement. The decay time with the control on decreased by 40 seconds.It became 5 seconds shorter than with the control off. See klog entry 14574.

    • The mystery then becomes the mode IP-L at 671 mHz, which is above the UGF and yet the decay time with the control on is 81 seconds shorter than with the control off. In principle the control system shouldn't be doing anything. I will add an notch at 671 mHz just to check the effect.

Type-Bp

Type-C

Controls

Electronics

Post O3

  • Post Obs. tasks are on going. Real-time model was modified in this week. Sensor correction for SRs and SR suspension update are planed in the next week.
  • The extended chief meeting was held on 15th. DRFPMI commissioing was scheduled in Jul.-Aug. The tasks towards O4 will be started from Sep.
  • Proposal on suspension commissioning was shown in the extended chief meeting.

  • "Remote/onsite support on VIS troubles by VIS group members with shift style" is requested for the DRFPMI commissioing.
  • Schedule towards O4 was revised again.

cf. Post Obs. task (Request), Task for O3c (Plan, Sheet), Task towards O4 (List).

Safety

Discussion

Travel Plans

Next meeting

  • On 2020/6/26(Fri)

KAGRA/Subgroups/VIS/VISMinutes20200619 (last edited 2020-06-19 15:15:23 by RyutaroTakahashi)