= ISC Meeting on 2016/8/8 14:00 - 15:00 = eZuce: http://srn.ezuce.com/joinSRN?meeting=MtM8Ma2B2eDuDv9s9sDs9t Participants: Enomoto, Kokeyama, Nagano, Kambara, Arai, Akutsu == Minutes == * bKAGRA Phase 1 HOM structure / ASC [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 -> confirm with Shoda-san again [Michimura] * even if we move by 1.20 cm, PRMI is still unstable in worst RoC error case * effect on WFS from RF HOMs should be [who?] * feedback topology and noise study should be done [Enomoto?] * Noise``Budget for Arm Length Stabilization [Kambara] ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5485|JGW-L1605485]]) * 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 (by UToyama or AEL?) should be fixed soon * IMC sideband frequency [Michimura] * f2/8*2.45 = 13.78 MHz plan was explained briefly * we will decide on the next meeting == 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]]) * we found mistake in the HOM structure check code * PR2-PR3 length re-calculation ongoing * we can move PR2/3 by 1.20 cm at max [Shoda,ATC] * Comments * Feedback topology. Change which mirror to feedback depending on the frequency? * Using DC signals for TMs may not be good from the view point of noise. * How to measure the precise distance between PR2-PR3? * How to de-couple the distance error and ROC errors? * 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] * bKAGRA Phase 1 initial alignment / commissioning plan [Michimura]: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=5274|JGW-T1605274]] * discussed at Extended Chief Meeting on July 4 ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5352|JGW-G1605352]]) * beam profiling plan should be compatible with vacuum plan; MIF will lead the planning * how to extract AS beam should be fixed by MIF * CRYp agreed on installing ETMY earlier by two months (ETMY CRYp: 2017.8-9, ETMX CRYp: 2017.12-2018.1) * use 2017.10-11 to test PR-ETMY and ETMY cooling * '''negotiate with CRYp to fix ETMY cooling schedule''' * 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 * '''where did front/rear panels go?''' * 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 * 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) * '''we have to request AEL to make interface board''' * RF Patch Panel modification [Michimura->Niigata students?] * outsource? * 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 * '''sideband frequency for IMC? (should be determined before EOM production; by the end of 2016.8)''' * f2/8*2.45 = 13.78 MHz for IMC anti-resonance? * Arm Length Stabilization plan ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5353|JGW-T1605353]]) * ALS Meeting on July 27 ([[KAGRA/subgroup/ifo/MIF/Minutes20160727|Minutes page]]) * agreed that the default plan is to use Tatsumi et al. configuration and to put AUX lasers at PSL table in the clean booth * noise study [Kambara](boot camp on August 1-5 at Hongo) * started with reproducing Tatsumi model ([[https://granite.phys.s.u-tokyo.ac.jp/trac/LCGT/browser/trunk/kagranoisebudget/GreenLock|GreenLock NoiseBudget SVN]]) * Tasumi Simulink model and Kambara Noise``Budget model basically agreed ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5485|JGW-L1605485]]) ----- * 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] * Doi-san said he will help. * 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] == Next meeting == 2016/8/22 14:00 - 15:00 [[LCGT/subgroup/ifo/ISC/Meetings|back to Meetings page]]