= 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 [[LCGT/subgroup/ifo/ISC/Meetings|back to Meetings page]] == Minutes == * bKAGRA Phase 1 optical configuration study [Michimura] * ASC sensing matrix for [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5362|JGW-T1605362]] was updated to reflect PR2-PR3 length decision [Enomoto] * summary of Phase 1 study [Michimura] ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5595|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 * RF generation scheme [Michimura] * ALS sideband frequencies [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5626|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? * 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] ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5362|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 [[https://dcc.ligo.org/LIGO-G080467|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?] * 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] ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5595|JGW-T1605595]]) * bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=5274|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] * bKAGRA Phase 1 analog electronics ([[KAGRA/Subgroups/MIF/AEL|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 [[https://dcc.ligo.org/LIGO-D1000124/public|LIGO-D1000124]], but we will omit [[https://dcc.ligo.org/LIGO-D1000064/public|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? [[https://dcc.ligo.org/LIGO-D1002178/public|LIGO-D1002178]] * Output optical tables [Michimura] ([[KAGRA/Subgroups/IOO/OutputTables|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 ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5493|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? [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5626|JGW-T1605626]] * Arm Length Stabilization plan ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5353|JGW-T1605353]]) * Noise``Budget [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? * 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? ([[https://dcc.ligo.org/LIGO-T1000090|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: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5334|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 ([[KAGRA/Subgroups/MIF/TaskList|TaskList]]) [Michimura]