ISC Meeting on 2017/4/10 14:00 - 15:00
Participants:
Next meeting
2017/4/24 14:00 - 15:00
Agenda
OFI and OMC status (JGW-T1706334) [Somiya]
new AS optics layout: SRM -> OMMT1 -> OMMT2 -> OFI -> STM -> OMC
- look for OFI with larger aperture [Somiya]
- OMC should be actuated also
- prototype OMC for practice of gluing, locking
Actuator noise modeling [Michimura,Miyamoto] (JGW-G1706333)
now included quantum noise and magnetic noise (JGW-T1503453)
- do we use ALS DIFF or IR DARM quantum noise for ETMs?
actuator design for cryogenic payload (JGW-G1605938)
magnets for Marionette too small? (ActuatorDesign wiki)
- use BF also for locking
magnetic noise JGW-T1504459 [Shimoda]
- got measured spectrum from Tanaka
Recommendation from ISC: Bigger magnets for Marionette of cryopayload [Aso->Tomaru, Michimura->Miyamoto]
- range should be ok, but to be more safe
- include local damping servo of Type-A (room temperature part)
is actuator efficiency measured at cryogenic temperature? [Michimura-> ask Miyamoto]
SmCo increases its magnetic moment by 5% at cryogenic temperature
- try including ALS sensing noise (shot noise, frequency noise etc.) to check actuator range
- confirm with VIS people if velocity requirement from lock acquisition is achievable or not
What can we do now?
- RF PD/QPD characterization
- electronics and cabling diagram
- RT modeling, MEDM screens, guardian scripts
better modeling (Optickle, Finesse, FFT, NoiseBudget, etc.) for ALS and intermediate configurations
- RF generation scheme, RF AM generation scheme
- AS optics (OMC, OFI, OMMT)
- initial alignment planning
- in-vacuum optics/electronics design
- 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 faint transmitted beam after ETM installation (~0.25uW)
- use green?
- BS transmission for green is S:99.40% P:97.85% at 45 deg
- 100 mW green beam from PR gives ~0.12 mW at ETMY transmission
- 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
- how to peel off the first contact?
- we cannot see the beam on ETM with IR cards with WAB
- first priority is cryopayloads and evacuation/cool-down
camera to see ETM HR surface [Akutsu, Inoue, Kokeyama]
CAL report (JGW-G1605737)
- wide angle baffle modification is needed to see the ETM edge
- how to extract AS beam should be fixed by MIF
extract SR2 reflected beam at SR3 chamber (decided at the meeting on Sept 13)
Layout around SRs (JGW-T1605967)
- IMMT1-IMMT2 beam collimation plan not yet [MIF]
- green alignment plan not yet [MIF]
TMS possible without ITM? [Akutsu->Michimura]
- check q-parameter at TMS witouht ITM
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
Quad IQ Demodulator LSC to ASC
- 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 JGW-D1504460
- we will omit RF monitor for now, and add them later
- front/rear panels, RF amps, 8-way splitters, couplers, cables and connectors at Mozumi office loft
- RF Frequency Doubler
what's the frequency? [Kamiizumi->Michimura]
- thought used for 2*f1,2*f2, but aLIGO uses them for ALS
Requested Universal Whitening Filter with DC Power to AEL (JGW-T1605839)
see DCQPDDriverList (see, also, DCQPDList)
- need to coordinate with subgroups (MIF, IOO, AOS, VIS, CRY)
- Quad IQ Demodulator heat-up issue
- RF PDs and RF QPDs
- RF PD / RF QPD noise and transimpedance characterization
- we need permanent test bench
- 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
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
- all the optical tables purchased and delivered to tunnel
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?
ask LIGO people how they are fixing the cables
- no special vibration / heat treatment [from Kawabe]
- 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 (calculation method)
- discuss with Aso and redo calculation
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"
in case of KAGRA, we don't need Frequency Doubler or Frequency Divide By Two for ALS
- is this true?
- 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]
- 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 is TMS-like plate spring and single pendulum [Somiya]
Task list update (TaskList) [Michimura]