ISC Meeting on 2020/07/06 13:30 - 14:30

Participants: Shinji Miyoki, Haoyu Wang, Eleonora Caposaca, Kiwamu Izumi, Koji Nagano, Masayuki Nakano, Matteo Leonardi, Osamu Miyakawa, Ryutaro Takahashi, Kentaro Somiya, Tomotada Akutsu, Yoichi Aso, Yuta Michimura

Zoom meeting: https://zoom.us/j/5045179604

Your time zone: https://www.timeanddate.com/worldclock/fixedtime.html?iso=20200706T0430

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Minutes

Agenda

RECORD THE MEETING
Summary of current measurements so far
- LSC sensing matrix, measurements vs simulation
  - Optickle simulation: https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=11767
    - Parameter choice of "BRSE_SDMR1_17_45" OK?
  - Measurements: https://klog.icrr.u-tokyo.ac.jp/osl/?r=14515, https://klog.icrr.u-tokyo.ac.jp/osl/?r=14593
- Schnupp asymmetry measurements
  - Time of flight measurement successful https://klog.icrr.u-tokyo.ac.jp/osl/?r=14575
- PRC length measurements
  - PRY length: 68.28 m with the error of roughly 1 m (designed: 64.926 m) https://klog.icrr.u-tokyo.ac.jp/osl/index.php?r=14555
  - PRX length: about 68 m (designed: 68.2559 m) https://klog.icrr.u-tokyo.ac.jp/osl/?r=14633
  - Actuator efficiency inconsistent between measurements?
- OMC scan to see mode content of AS beam
  - Summary http://klog.icrr.u-tokyo.ac.jp/osl/?r=14696
  - carrier and f1 3rd mode is overlapped? http://klog.icrr.u-tokyo.ac.jp/osl/?r=14620
- Frequency noise coupling
  - https://klog.icrr.u-tokyo.ac.jp/osl/?r=14614
- Arm cavity round-trip loss measurement with birefringence effect correctly taken into account
  - P-pol and S-pol PDs placed on POS table https://klog.icrr.u-tokyo.ac.jp/osl/?r=14622
Birefringence simulations with FINESSE
- Any volunteer to add polarization to FINESSE code?
- "directional beamsplitter" could be used to simulate DRFPMI with FINESSE using s/p two-world approach [Haoyu]
  - https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=11792
New ISC meeting slot?
- Bi-weekly SEO and Chief meeting on Modays, from 15:00 JST
- How about bi-weekly Mondays 13:00 JST (before chief meetings)

Copy from previous meeting

Simulation activities necessary
- LSC and ASC simulations with current ITMs and current interferometer setup
  - Especially LSC simulations not done for PRFPMI and DRMI, and 3f locking
  - Compare measured LSC and ASC sensing matrices with simulations
  - Compare measured recycling gain (for carrier and sidebands) with simulations
  - Compare measured AS mode content with simulations
  - Compare measured MICH/PRCL/SRCL controls noise coupling with simulations
  - Compare measured intensity/frequency noise coupling with simulations
- Thermal lensing in BS
Measurements necessary to do simulation work
- PRC (SRC) length and Gouy phase
- Schnupp asymmetry
- modulation depth (arm cavity scan)
- arm cavity length (arm cavity scan)
- arm cavity round-trip loss measurement with birefringence effect correctly taken into account (with PBS at POP/POS and TRX/TRY) JGW-T2011633
- Power recycling gain for carrier and sidebands
- Throughput from IMC output to AS RF, OMC DC, REFL, POP, TRX, TRY
Measurements necessary to compare the result with simulation
- frequency/intensity noise coupling, down to ~10 Hz
- Measure power recycling gain for sidebands (POP 2f with FPMI locked and PRFPMI locked)
- DRFPMI LSC and ASC sensing matrix
  - LSC https://klog.icrr.u-tokyo.ac.jp/osl/?r=14515
- MICH/PRCL/SRCL to DARM coupling
- Measure MICH contrast defect with MICH locked and FPMI locked
- OMC cavity scan to scan mode content of AS beam
- https://docs.google.com/spreadsheets/d/1w4q8OvX9E6nkYSgshLYLoZH5yvQXHvGmL1agux8ztx0/edit#gid=0
- Type-A, B, Bp actuation efficiency measurements (for actuator noise)