ISC Meeting on 2016/6/27 14:00 - 15:00

eZuce: http://srn.ezuce.com/joinSRN?meeting=MtM8Ma2u2DDsDe9s9eDs9t

Participants: Y. Aso, T. Akutsu, H. Yamamoto, K. Kokeyama, O. Miyakawa, Y. Michimura

Minutes

• bKAGRA Phase 1 analog electronics
  • Quad IQ Demodulator heat-up issue
    • 1st stage amp is heating up

    • decide if we need 1st stage amp or not [Michimura]

  • remake of Quad IQ Demodulator LSC to ASC
    • MIF will take care istead of AEL
    • mass production will be taken care by AEL
  • RF Distribution Amplifier
    • we will omit RF monitor for now, and add them later

    • ask LIGO people for necessity of RF monitor [Michimura]

• RF generation scheme
  • be careful of harmonics generator generating unwanted harmonics
• OFI telecon summary
  • calculation by Somiya show single pendulum is enough for OFI and OMC

  • but we need cross check -> Somiya, Hiro

• 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

    • talk with Kawamura who to assign [Michimura]

    • possibility of buying baffles next FY? -> ask SEO [Aso]

• iKAGRA post-run calibration mystery [Aso]
  • mysterious LPF was from saturation

  • write an elog about this conclusion [Aso]

• 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
• 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

Agenda

• bKAGRA Phase 1 optical configuration study [Michimura]
  • HOM structure / LSC / ASC check [Michimura]

    • initiated Optickle 2 modeling: KAGRAOptickle SVN (login required)

    • Optickle (Optickle2) seminar on July 1 densuke

      • announced to Toyama and Niigata students
    • length sensing matrix is OK
  • continue checking dummy ETM availability [Hirose]
    • cost estimate arrived
  • 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]
  • check if dummy payload is quiet enough to make PRMI [Michimura]

• bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: JGW-T1605274

  • we actually had only two months for room temperature PRMI with dummy payload
    • PR mirrors will be ready by the end of 2017.7 (BS ready by the end of 2017.3)
  • what should we do?
    • initial alignment to both ends before cryopayload is ready (2017.8-9)
    • PR-ETMX cavity during two months of ETMY cryopayload installation?
      • can we do ASC with such a low finesse?
      • PAB said we should do ETMY installation first (since Xend is dangerous)

    • PRM-PR2-PR3 cavity? -> unstable

  • possibility of installing cryopayload earlier is being discussed [Ando, Saito, CRYp]

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

  • request for AEL [Michimura]
  • Quad IQ Demodulator heat-up issue [AEL]
  • remake IQ Demodulator LSC to ASC temporarily for IMC WFS by 2016.10
    • confirmed with Miyakawa that AEL will take care

  • assemble RF Distribution Amplifier [Michimura->Niigata students?]

    • MIF will take care of assembling and purchasing with AEL budget
    • in the process of ordering RF amp (Wenzel LNBA-10-23-CK or LNBA-11-23-CK)
    • in the process of ordering RF splitter (Mini-Circuits ZCSC-8-1+)

    • basically copy of LIGO-D1000124, but we might omit Interface

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

• 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)?
  • use multiple signal generators with frequency doubler and differential frequency generator?

• Summary of OFI telecon on June 24 JGW-G1605313 [Somiya]

  • reduce number of output steering mirrors (OSM) from two to one
  • move OFI postion to be between OMMT2 and OSM
  • suspend OMC and IFI both by single pendula

• bKAGRA optical layout around PRC [Aso]

  • POY beam is clipped by PR3 optical bench suspension wire CAD drawing by Shoda

  • JGW-T1605261 (cartoon)

• iKAGRA post-run calibration mystery [Aso]

  • klog #1767

  • mysterious LPF was probably from saturation (is this end of the story?)

  • Miyo-kun did time delay fitting: Jupyter Notebook, Files in Dropbox

• Requirement for the noise of watchdogs for coil drivers [Aso]

  • if watchdog resistance noise should be less than DAC noise, dR < 6e-8 Ohm/rtHz (High Power Coil Driver case), dR < 5e-6 Ohm/rtHz (Low Power Coil Driver case), both at 10 Hz

  • too meet actuator noise requirement, dR < 8e-5 Ohm/rtHz (for BS/SRs), dR < 6e-5 Ohm/rtHz (for PRs), both at 10 Hz

  • watchdog resistance fluctuation was measured to be dR < ~1e-6 Ohm (measurement noise limited) (JGW-E1605270)

  • see, also, VISMinutes20160603

• Viewport quality for GV between SRM and OMMT [Akutsu]

• BS baffle could make contract defect? (LIGO-T1000090) [Akutsu,Hiro]

• 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, ask Takahashi-san to add drivers to his list: JGW-L1605193

  • 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
• Magnetic noise, actuator noise calculation for cryogenic payload [Michimura]

• Task list update (TaskList) [Michimura]

Next meeting

2016/7/25 14:00 - 15:00

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