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ISC Meeting on 2020/06/15 14:00 - 15:00
Participants:
Zoom meeting: https://zoom.us/j/6676627462
Next meeting
TBD
Minutes
Agenda
- Useful links to know KAGRA interferometer design and status
List of optical parameters OptParam
MIF Design document JGW-T1200913
Interferometer design paper Phys. Rev. D 88, 043007 (2013)
Latest KAGRA status paper arXiv:2005.05574
Summary of measurements related to the interferometer so far Minutes20200309
O4 schedule JGW-E1809209
- Interferometer issues which require simulation studies
ITMs have different transmission (ITMX: 0.444 % ITMY: 0.479%) JGW-T1910352
ITMs have inhomogeneity Phys. Rev. D 100, 082005 (2019)
ITMs have inhomogeneous birefringence JGW-G1910369, JGW-G1910388, JGW-T2011633
So far no success in locking DRFPMI JGW-G2011693
WFS not working well JGW-G2011687
Laser intensity and frequency noise couplings are too high JGW-T2011662
Carrier power recycling gain for PRMI (roughly 3) and PRFPMI (11-12) are too different, which could be due to the Lawrence effect JGW-T2011633
- Status of simulation activities
LSC simulations with Optickle originally by Yoichi Aso https://granite.phys.s.u-tokyo.ac.jp/svn/LCGT/trunk/mif/IFOmodel
Used for designing the interferometer, and deriving requirements JGW-T1200913
Simulations for O3 by Yutaro Enomoto JGW-T1910341
Mach-Zehnder modulator simulations by Kohei Yamamoto Classical and Quantum Gravity 36, 205009 (2019)
ASC simulations with Optickle originally by Yuta Michimura https://granite.phys.s.u-tokyo.ac.jp/svn/LCGT/trunk/mif/ASC-Optickle
Used for designing the interferometer JGW-T1200913
Simulations for O3 by Yuta Michimura JGW-T1910359
FINESSE model originally by Kentaro Somiya JGW-T1402434 (any updated version?)
Used for OMC design JGW-T1808043, Optical Review 22, 149-152 (2015), J. Phys.: Conf. Ser. 957, 012009 (2018)
ITM inhomogeneity effects Phys. Rev. D 100, 082005 (2019)
- Also being used for simulating birefringence effects by Keiko Kokeyama
- Parametric instability by Kiichi Kaihotsu, Kazuhiro Yamamoto
Activities in University of Toyama using COMSOL JGW-E1910382
- Thermal lensing by Kentaro Somiya ?
- Thermal lensing in cryogenic sapphire mirrors should be small (orders of magnitude smaller than room temperature fused silica)
- Thermal lensing in room temperature fused silica BS needs investigation
- Rough estimation by Hiroaki Yamamoto shows it is OK-ish, comparing the result with aLIGO
- Further investigation necessary (also for future higher power)
- 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
- LSC and ASC simulations with current ITMs and current interferometer setup