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| * 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 |
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]
- Quad IQ Demodulator heat-up issue
- 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
Adgenda
- 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]
- HOM structure / LSC / ASC check [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]
- we actually had only two months for room temperature PRMI with dummy payload
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]
- 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