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  * this gives 50 mm * (1.4e-3 N/A * 4) * 4 magnets * 1/80 A/V / 9.6e-4 kg*m^2  / (2*pi*3 Hz)^2 = 4.1e-5 rad/V efficiency   * this gives 50 mm * (1.4e-3 N/A * 4) * 4 magnets * 1/80 A/V / 9.6e-4 kg*m^2^  / (2*pi*3 Hz)^2^ = 4.1e-5 rad/V efficiency

ISC Meeting on 2016/10/17 14:00 - 15:00

Participants:

Next meeting

2016/11/14 14:00 - 15:00 ??

back to Meetings page

Agenda

  • MIR update [Hirose]
    • coated PRM reflectivity acceptable? {*}

      • required spec was 10 +0.1 % / -0 %, but measured value was 10.35 %
  • bKAGRA Phase 1 optical configuration study [Michimura]
    • summary: JGW-T1605595

    • ASC [Enomoto]
      • noise study by NoiseBudget [Enomoto]

        • Enomoto volunteered to do ASC NoiseBudget; meeting on Sept 27

          • trouble on number of licenses and library links, but finally able to run example model
      • effect on WFS from RF HOMs [who?]
    • check if reference spheres for PR mirrors are available at Caltech [Hirose]
      • 9.0m (CC), 11.5m (CC), 6.5m (CC), 5.0m (CC), 34m (CX), 36m (CX) were available
      • PR2/SR2 is -3.0764m/-2.9872m and PR3/SR3 is 24.9165m. Maybe 5.0m TS can be used for PR2/SR2.
      • what about PR3/SR3, PRM/SRM?
    • check if IMC length stability and others are compatible with 3-km PRMI [Michimura]
  • bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: JGW-T1605595

    • procedure summarized in JGW-T1605692 {*}

      • presented at Chief Meeting on Sept 26
      • TMS BRT alignment could be tough because of dim transmitted beam after ETM installation

        • use green?
      • check optical layout [Michimura->Aso]

    • check if ETM transmitted beam can go through when ETM is not installed [Michimura] {*}

      • ETM transmitted beam can reach EXT/EYT when no wedge (5.6 mm shifted from the center of EXT/EYT)
      • EXT/EYT tanks/ducts are installed considering ETM wedge effect
    • wide/narrow angle baffles for Phase 1? [Akutsu] {*}

      • talk with Uchiyama & Saito on Sept 27-28?

        • as for NAB: install if possible, but maybe without suspension
        • as for WAB: try WAB with suspension at EXC, maybe no installaton at EYC
        • first priority is cryopayloads and evacuation/cool-down
    • discussion on camera to see ETM HR surface started [Akutsu, Inoue, Kokeyama] {*}

      • start with a plan to use viewport at EXA/EYA
      • baffle design have to be modified to see the edge of ETM
      • meeting at Kamioka on Oct 5 [Akutsu, Inoue, Kokeyama]
      • CAL report (JGW-G1605737)

    • how to extract AS beam should be fixed by MIF
      • extract SR2 reflected beam at SR3 chamber {*}

    • IMMT1-IMMT2 beam collimation plan not yet [MIF]
    • green alignment plan not yet [MIF]
  • 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 instead 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
      • Nakano found front/rear panels -> Mozumi office loft

      • ordered RF amp (Wenzel LNBA-11-23-CK-100-15) -> not yet arrived (by mid-November?) {*}

      • 8-way splitter (Mini-Circuits ZCSC-8-1+), coupler (Mini-Circuits ZX30-20-4) arrived at Kamioka -> Mozumi office loft

      • cables and connectors to assemble one chassis by hand arrived at Kamioka -> Kokeyama's desk

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

      • asked AEL to make RF amplifier interface board (which is also used for Frequency Doubler) [Michimura]
    • RF Patch Panel modification [Michimura->Niigata students?]

      • one by one by hand is tough; outsource?
    • Electronics request meeting with Miyakawa/Kamiizumi on Aug 24
      • photos of the assembled chassis are helpful for AEL
  • RF PDs and RF QPDs
    • RF PD / RF QPD noise and transimpedance characterization [NiigataU?]
      • need to check RF QPDs for IMC WFS, by the end of Oct 2016
      • IR LED is at Kamioka, no network analyzer at Kamioka (one at Toyama U and the other at Kashiwa)
    • RF PD modification [who?]
      • fix DC path
      • solve single supply issue (RF PDs easily break when accidentally supplied with single)
      • fix plugs so that Dsub 9pin cable fixes better
  • Output optical tables [Michimura] (OutputTables wiki)

    • Kawamura suggested to move this task from IOO to MIF

    • vacuum optics to extract beams for each port (except for REFL and AS DC) and related beam shutters will also be MIF task
    • MIF and IOO agreed, SEO agreed, next step is budget migration
  • 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
    • MIF and IOO agreed to use 13.78 MHz (~= f2/8*2.45) for IMC sideband (JGW-T1605493)

    • MIF agreed to use 32 MHz and 33 MHz for ALS sidebands JGW-T1605626

    • may be IMC sideband (and ALS sidebands) should also needs to be phase locked with f1/f2/f3 to avoid "whistling noise"
  • Arm Length Stabilization plan (JGW-T1605353)

    • NoiseBudget [Kambara]

      • results agreed with Tatsumi Simulink model
      • include fiber noise (fiber setup is different from Tatsumi model)
        • fiber length? how to do the wiring?
      • 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 should be fixed soon
        • keep in touch with AEL group
      • local oscillator phase noise, optical fiber wiring {*}


  • Requirement on actuator range for IMMT [Ohishi]
    • magnet size: 2 mm dia, 5 mm long
    • coil turns: 39?
    • this gives 4 times larger efficiency than the IMC coil efficiency
    • this gives 50 mm * (1.4e-3 N/A * 4) * 4 magnets * 1/80 A/V / 9.6e-4 kg*m2  / (2*pi*3 Hz)2 = 4.1e-5 rad/V efficiency

    • is this enough?
  • 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
      • budget for baffles around POY and POP were shifted to next FY [SEO]
  • 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]
    • announced to IOO mailing list
    • need to update the cabling diagram
  • 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]

    • OFI, OMMT, OMC meeting on 2016.9.14
      • design suspended table similar to TMS? {*}

  • Magnetic noise, actuator noise calculation for cryogenic payload [Michimura]
    • actuator noise calculation on going by Miyamoto & Okutomi {*}

  • Task list update (TaskList) [Michimura]

KAGRA/subgroup/ifo/MIF/Minutes20161017 (last edited 2016-10-17 20:33:46 by YutaMichimura)