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[[LCGT/subgroup/ifo/ISC/Meetings|back to Meetings page]]
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=== Next meeting ===
2016/9/5 14:00 - 15:00

[[LCGT/subgroup/ifo/ISC/Meetings|back to Meetings page]]
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== Next meeting ==
2016/8/22 14:00 - 15:00

ISC Meeting on 2016/8/8 14:00 - 15:00




  • bKAGRA Phase 1 HOM structure / ASC [Enomoto] (JGW-T1605362)

    • decided to move PR2/3 by 1.20 cm -> confirm with Shoda-san again [Michimura]

    • even if we move by 1.20 cm, PRMI is still unstable in worst RoC error case
    • effect on WFS from RF HOMs should be [who?]
    • feedback topology and noise study should be done [Enomoto?]
  • NoiseBudget for Arm Length Stabilization [Kambara] (JGW-L1605485)

    • results agreed with Tatsumi Simulink model
    • include fiber noise (fiber setup is different from Tatsumi model)
    • include phase noise from mirror vibration for IR beat setup (it is one of the limiting noise source for aLIGO)
    • schedule and plan for the procurement of circuits (by UToyama or AEL?) should be fixed soon
  • IMC sideband frequency [Michimura]
    • f2/8*2.45 = 13.78 MHz plan was explained briefly
    • we will decide on the next meeting

Next meeting

2016/9/5 14:00 - 15:00

back to Meetings page


  • bKAGRA Phase 1 optical configuration study [Michimura]
    • HOM structure / ASC check [Enomoto] (JGW-T1605362)

      • we found mistake in the HOM structure check code
        • PR2-PR3 length re-calculation ongoing
        • we can move PR2/3 by 1.20 cm at max [Shoda,ATC]
      • Comments
        • Feedback topology. Change which mirror to feedback depending on the frequency?
        • Using DC signals for TMs may not be good from the view point of noise.
        • How to measure the precise distance between PR2-PR3?
        • How to de-couple the distance error and ROC errors?
    • check if reference spheres for PR mirrors are available at Caltech [Hirose]
    • check if IMC length stability and others are compatible with 3-km PRMI [Michimura]
  • bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: JGW-T1605274

    • discussed at Extended Chief Meeting on July 4 (JGW-G1605352)

      • beam profiling plan should be compatible with vacuum plan; MIF will lead the planning
      • how to extract AS beam should be fixed by MIF
      • CRYp agreed on installing ETMY earlier by two months (ETMY CRYp: 2017.8-9, ETMX CRYp: 2017.12-2018.1)
        • use 2017.10-11 to test PR-ETMY and ETMY cooling
          • negotiate with CRYp to fix ETMY cooling schedule

  • bKAGRA Phase 1 analog electronics (Analog Electronics for ISC) [Michimura]

    • Quad IQ Demodulator heat-up issue
      • 1st stage amp is heating up
      • we have to decide if we need 1st stage amp or not

    • remake of Quad IQ Demodulator LSC to ASC [Michimura->Niigata students?; by 2016.10]

      • MIF will take care istead of AEL
      • mass production will be taken care by AEL
      • 4-way splitter (Mini-Circuits ZFSC-4-1-S+) arrived at Kamioka -> Mozumi office loft

    • RF Distribution Amplifier [Michimura->Niigata students?; by 2016.10]

      • we will omit RF monitor for now, and add them later
      • where did front/rear panels go?

      • ordered RF amp (Wenzel LNBA-11-23-CK-100-15)
      • 8-way splitter (Mini-Circuits ZCSC-8-1+), coupler (Mini-Circuits ZX30-20-4) arrived at Kamioka -> Mozumi office loft

      • basically copy of LIGO-D1000124, but we will omit Interface for the first stage

      • ask LIGO people for necessity of RF monitor [Michimura]
        • RF monitor was used in aLIGO for noise hunting and IFO health check (input from Izumi)
      • we have to request AEL to make interface board

    • RF Patch Panel modification [Michimura->Niigata students?]

      • outsource?
  • RF generation scheme [Michimura]
    • f1 = 3/8*f2, f3 = 10/8*f2
    • we need 2*f1, 2*f2, f3-f1, f3-f2 as well
    • use harmonics generator (x2, x3, x6, x8, x10, x16 for f2/8 = 5.62698725 MHz (FSR for IMC))
      • seeking for vendors
    • sideband frequency for IMC? (should be determined before EOM production; by the end of 2016.8)

      • f2/8*2.45 = 13.78 MHz for IMC anti-resonance?
  • Arm Length Stabilization plan (JGW-T1605353)

    • ALS Meeting on July 27 (Minutes page)

    • agreed that the default plan is to use Tatsumi et al. configuration and to put AUX lasers at PSL table in the clean booth
    • noise study [Kambara](boot camp on August 1-5 at Hongo)

  • bKAGRA optical layout around PRC
    • POY clipping issue will be solved by modifying PR3 optical bench suspension [Shoda]
    • we need layout CAD for POY pickoff mirror, POP pickoff mirror to design baffles
      • possibility of buying baffles next FY? -> ask SEO [Aso]

      • ask SEO to hire a person dedicated for optical CAD
      • layout CAD will be prepared by each subgroup for the time being
  • iKAGRA post-run calibration mystery [Aso]
    • mysterious LPF was from saturation
    • write an elog about this conclusion [Aso]

  • Requirement for the noise of watchdogs for coil drivers [Aso]
    • recent result show dR < 1e-7 Ohm/rtHz, so it may meet the requirement

    • slow (~20 min) drift at dR ~ 5e-4 Ohm -> this should be negligible

  • Viewport quality for GV between SRM and OMMT [Akutsu]
    • aLIGO case: SRM-OFI-viewport, KAGRA case: SRM-viewport-OMMT-OFI
    • aLIGO viewport is always closed
    • if we need super quality viewport, we have to decide soon

  • BS baffle could make contract defect? (LIGO-T1000090)

    • ask Akutsu and Hiro
    • BS has 370 mm dia and beam at BS is 2*36 mm dia. So, it should be in principle OK. But recoil mass aperture should be considered.
  • bKAGRA ISC cabling [Michimura/Doi]
    • Doi-san said he will help.
  • Mirror absorption measurement status [Hirose]
  • Output optics status [Somiya]
    • suspensions for OMMT1/2 is same as IMMT1/2 (driver list for now: JGW-L1605334)

    • we have to make vacuum compatible PD/QPD for OMC by 2018.3
    • beam shutter: prototype done, AR coating and driver circuit design not yet
    • OMC suspension requirement cross check [Somiya]

  • Magnetic noise, actuator noise calculation for cryogenic payload [Michimura]
    • Ask Tomaru about the parameters and actuator design, range

  • Task list update (TaskList) [Michimura]

KAGRA/subgroup/ifo/MIF/Minutes20160822 (last edited 2016-08-22 16:55:11 by YutaMichimura)