ISC Meeting on 2016/10/17 14:00 - 15:00
Participants: Michimura, Kambara, Aso, H. Yamamoto, K. Arai, Miyamoto, Somiya, Kokeyama
Next meeting
2016/11/2 14:00 - 15:00 ?? or 2016/11/14 14:00 - 15:00 ??
Agenda
- MIR update [Hirose]
coated PRM reflectivity acceptable?
- required spec was 10 +0.1 % / -0 %, but measured value was 10.35 %
MIF group concluded that this is acceptable according to LSC/ASC shot noise calculation JGW-L1605744
- 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) -> 6 arrived (Mozumi office loft), 4 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
does anyone have a photo of Frequeny Doubler? LIGO-D1002178
photos arrived JGW-T1605492
- photos of the assembled chassis are helpful for AEL
- Quad IQ Demodulator heat-up issue
- 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
- RF PD / RF QPD noise and transimpedance characterization [NiigataU?]
Output optical tables [Michimura] (OutputTables wiki)
- 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
make budget estimate and send it to Kawamura [Michimura]
- EXT/EYT tables
get foot positions and send it to Saito [Michimura]
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
- Magnetic noise, actuator noise calculation for cryogenic payload
magnetic noise JGW-T1504459 [Shimoda]
actuator noise and range calculation on going [Miyamoto(JGW-G1605746), Okutomi]
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
- IMMT resonant frequencies: pitch ~1.8 Hz, yaw ~1.5 Hz
this gives 50/sqrt(2) mm * (1.4e-3 N/A * 4) * 4 magnets * 1/80 A/V / 9.6e-4 kg*m2 / (2*pi*1.8 Hz)2 = 8e-5 rad/V efficiency in pitch
- is this enough?
- IMC mirror (Type-C + stack) drift in yaw was less than 1 mrad/month, pitch was much less [Nakano]
- iKAGRA ETM (Type-C w/o stack) drift was ???
- 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"
- 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?
Task list update (TaskList) [Michimura]