ISC Meeting on 2016/9/5 14:00 - 15:00
Participants: Michimura, Enomoto, Arai, Aso, Haino, Miyakawa
Next meeting
2016/9/20 14:00 - 15:00
Minutes
- bKAGRA Phase 1 optical configuration study [Michimura]
ASC sensing matrix for JGW-T1605362 was updated to reflect PR2-PR3 length decision [Enomoto]
summary of Phase 1 study [Michimura] (JGW-T1605595)
- MIF agreed with this goal
- Output optical tables [Michimura]
- need to check noise performance and transimpedance RF PDs and RF QPDs
- RF PDs could have higher noise (~5 mA?) than aLIGO ones (~2 mA?) because of the modification done
- we also have to modify RF PD to
- 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
- beam shutter engineering could be very tough
- need to check noise performance and transimpedance RF PDs and RF QPDs
- RF generation scheme [Michimura]
ALS sideband frequencies JGW-T1605626
- MIF agreed with 32 MHz for ALSX, 33 MHz for ALSY plan
- Aperture of sapphire test mass
- Recoil mass aperture is 191 mm at min for HR side, 188 mm at min for AR(coil) side
- requiring diffraction loss of 10 ppm, 2.4 sigma aperture is needed
- considering 35.3 mm beam radius on ITM/ETM, 188 mm is tolerable for diffraction loss
- from order estimate, scattering noise should also be OK
- exp(-2*(188/2/35.3)^2) = 0.7 ppm scattering from recoil mass is smaller than few ppm scattering from mirror surface
- what is the baffle aperture?
- Recoil mass aperture is 191 mm at min for HR side, 188 mm at min for AR(coil) side
- bKAGRA optical layout around PRC
- POY clipping issue will be solved by modifying PR3 optical bench suspension [Shoda]
- budget for baffles around POY and POP were shifted to next FY [SEO]
- so we don't need precise layout CAD around POY and POP for now
Agenda
- bKAGRA Phase 1 optical configuration study [Michimura]
HOM structure / ASC check [Enomoto] (JGW-T1605362)
- decided to move PR2/3 by 1.20 cm
- this is possible even in vacuum [Shoda confirmed]
- adjustment takes only few minutes
precise TMS measurement can be done using transfer function measurement with injected sidebands trough IMC (see LIGO-G080467)
- consider using this technique
- cryopayload installation finish on Feb 2, 2018 and cool down start on Feb 19
- could be tough to do TMS tuning considering schedule
- effect on WFS from RF HOMs should be simulated [who?]
- feedback topology and noise study should be done [who?]
- decided to move PR2/3 by 1.20 cm
- 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]
summary of Phase 1 study [Michimura] (JGW-T1605595)
bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: JGW-T1605274
- beam profiling plan should be compatible with vacuum plan; MIF will lead the planning
- not only PR2-PR3 but also IMMT1-IMMT2
- how to extract AS beam should be fixed by MIF
- according to CRYp current schedule;
- Nov 1, 2017: ETMY CRYp installation done
- Nov 21, 2017: ETMY cool down starts
- Feb 2, 2018: ETMX CRYp installation done
- Feb 19, 2018: ETMY cool down starts
- we need more time for PR-ETMY cavity
negotiate with CRYp to fix ETMY cooling schedule
- initial alignment plan including green is taken cared by MIF [confirmed with Kawamura, Moriwaki on Aug 30]
- beam profiling plan should be compatible with vacuum plan; MIF will lead the planning
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
Nakano found front/rear panels -> Mozumi office loft
- 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
- ordered cables and connectors to assemble one chassis by hand [Kokeyama,Michimura]
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)
- 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
- 4 chasses of Quad IQ Demodulator ASC by July 2017 might be tough, but all the others are OK
- Quad IQ Demodulator ASC is not so high priority anyway (compared with coil drivers for VIS)
- Rear panels of RF Distribution Amplifier will be updated for RF monitor
- we might have to help them with ordering RF components
- photos of the assembled chassis are helpful for AEL
does anyone have a photo of Frequeny Doubler? LIGO-D1002178
- Quad IQ Demodulator heat-up issue
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, waiting for SEO to agree
- 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)
- sent email to Uehara; he is already tuning the resonance close to this value
- may be IMC sideband (and ALS sidebands) should also needs to be phase locked with f1/f2/f3 to avoid "whistling noise"
how to decide ALS sideband frequencies? JGW-T1605626
Arm Length Stabilization plan (JGW-T1605353)
NoiseBudget [Kambara]
- 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 should be fixed soon
- keep in touch with AEL group
- Aperture of sapphire test mass
- AR aperture is 204 mm dia for sapphire mirror
- this size is tolerable considering 35.3 mm beam radius on ITM/ETM and 2.7 sigma (1 ppm loss)
- Recoil mass aperture is 191 mm at min for HR side, 188 mm at min for AR(coil) side
- is this OK?
- what is the requirement for the recoil mass miscentering with respect to test mass center?
- AR aperture is 204 mm dia for sapphire mirror
- 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]
- need to announce to IOO,ISC mailing list; e-mailed to Doi-san for go sign
- 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]