= ISC Meeting on 2016/6/27 14:00 - 15:00 = eZuce: http://srn.ezuce.com/joinSRN?meeting=MtM8Ma2u2DDsDe9s9eDs9t Participants: Y. Aso, T. Akutsu, H. Yamamoto, K. Kokeyama, O. Miyakawa, Y. Michimura == Minutes == * bKAGRA Phase 1 analog electronics * Quad IQ Demodulator heat-up issue * 1st stage amp is heating up * '''decide if we need 1st stage amp or not [Michimura]''' * remake of Quad IQ Demodulator LSC to ASC * MIF will take care istead of AEL * mass production will be taken care by AEL * RF Distribution Amplifier * we will omit RF monitor for now, and add them later * '''ask LIGO people for necessity of RF monitor [Michimura]''' * RF generation scheme * be careful of harmonics generator generating unwanted harmonics * OFI telecon summary * calculation by Somiya show single pendulum is enough for OFI and OMC * but we need cross check -> Somiya, Hiro * 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 * '''talk with Kawamura who to assign [Michimura]''' * '''possibility of buying baffles next FY? -> ask SEO [Aso]''' * iKAGRA post-run calibration mystery [Aso] * mysterious LPF was from saturation * '''write an elog about this conclusion [Aso]''' * 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 * 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 == Agenda == * bKAGRA Phase 1 optical configuration study [Michimura] * HOM structure / LSC / ASC check [Michimura] * initiated Optickle 2 modeling: [[https://granite.phys.s.u-tokyo.ac.jp/trac/LCGT/browser/trunk/mif/KAGRAOptickle/bKAGRAPhase1/|KAGRAOptickle SVN]] (login required) * Optickle (Optickle2) seminar on July 1 [[http://densuke.biz/list?cd=bNJ9WSPSEQNxheCy|densuke]] * announced to Toyama and Niigata students * length sensing matrix is OK * continue checking dummy ETM availability [Hirose] * cost estimate arrived * 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] * check if dummy payload is quiet enough to make 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]] * we actually had only two months for room temperature PRMI with dummy payload * PR mirrors will be ready by the end of 2017.7 (BS ready by the end of 2017.3) * what should we do? * initial alignment to both ends before cryopayload is ready (2017.8-9) * PR-ETMX cavity during two months of ETMY cryopayload installation? * can we do ASC with such a low finesse? * PAB said we should do ETMY installation first (since Xend is dangerous) * PRM-PR2-PR3 cavity? -> unstable * possibility of installing cryopayload earlier is being discussed [Ando, Saito, CRYp] * bKAGRA Phase 1 analog electronics request for AEL ([[KAGRA/Subgroups/MIF/AEL|Analog Electronics for ISC]]) [Michimura] * request for AEL [Michimura] * Quad IQ Demodulator heat-up issue [AEL] * remake IQ Demodulator LSC to ASC temporarily for IMC WFS by 2016.10 * confirmed with Miyakawa that AEL will take care * assemble RF Distribution Amplifier [Michimura->Niigata students?] * MIF will take care of assembling and purchasing with AEL budget * in the process of ordering RF amp (Wenzel LNBA-10-23-CK or LNBA-11-23-CK) * in the process of ordering RF splitter (Mini-Circuits ZCSC-8-1+) * basically copy of [[https://dcc.ligo.org/LIGO-D1000124/public|LIGO-D1000124]], but we might omit [[https://dcc.ligo.org/LIGO-D1000064/public|Interface]] * RF Patch Panel modification [Michimura->Niigata students?] * 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)? * use multiple signal generators with frequency doubler and differential frequency generator? * Summary of OFI telecon on June 24 [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5313|JGW-G1605313]] [Somiya] * reduce number of output steering mirrors (OSM) from two to one * move OFI postion to be between OMMT2 and OSM * suspend OMC and IFI both by single pendula ----- * bKAGRA optical layout around PRC [Aso] * POY beam is clipped by PR3 optical bench suspension wire [[https://www.dropbox.com/s/4jio2tlmlavoffr/bKAGRA_wframes160621.dxf?dl=0|CAD drawing by Shoda]] * [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5261|JGW-T1605261]] (cartoon) * iKAGRA post-run calibration mystery [Aso] * [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=1767|klog #1767]] * mysterious LPF was probably from saturation (is this end of the story?) * Miyo-kun did time delay fitting: [[https://nbviewer.jupyter.org/urls/dl.dropbox.com/s/e7tj2xvc8krdo2w/Post-Run%20MICH%20Calibration.ipynb|Jupyter Notebook]], [[https://www.dropbox.com/sh/alk6mothy435dis/AABeRhaV6RRZ1CfUqnq6bc7ua?dl=0|Files in Dropbox]] * Requirement for the noise of watchdogs for coil drivers [Aso] * if watchdog resistance noise should be less than DAC noise, dR < 6e-8 Ohm/rtHz (High Power Coil Driver case), dR < 5e-6 Ohm/rtHz (Low Power Coil Driver case), both at 10 Hz * too meet actuator noise requirement, dR < 8e-5 Ohm/rtHz (for BS/SRs), dR < 6e-5 Ohm/rtHz (for PRs), both at 10 Hz * watchdog resistance fluctuation was measured to be dR < ~1e-6 Ohm (measurement noise limited) ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5270|JGW-E1605270]]) * see, also, [[KAGRA/Subgroups/VIS/VISMinutes20160603|VISMinutes20160603]] * Viewport quality for GV between SRM and OMMT [Akutsu] * BS baffle could make contract defect? ([[https://dcc.ligo.org/LIGO-T1000090|LIGO-T1000090]]) [Akutsu,Hiro] * 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, ask Takahashi-san to add drivers to his list: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5193|JGW-L1605193]] * 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 * Magnetic noise, actuator noise calculation for cryogenic payload [Michimura] * Task list update ([[KAGRA/Subgroups/MIF/TaskList|TaskList]]) [Michimura] == Next meeting == 2016/7/25 14:00 - 15:00 [[LCGT/subgroup/ifo/ISC/Meetings|back to Meetings page]]