Differences between revisions 146 and 147
Revision 146 as of 2017-09-20 12:30:26
Size: 4249
Editor: EnzoTapia
Revision 147 as of 2017-09-20 12:31:57
Size: 4261
Editor: EnzoTapia
Deletions are marked like this. Additions are marked like this.
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 * Remove F0 keystone top plate (including yaw stepper) and immobilize SF/... in yaw.
 * Attach lifting fixture.
 * --(Remove F0 keystone top plate (including yaw stepper) and immobilize SF/... in yaw.)--
 * --(Attach lifting fixture.)--

VIS Type B BS Near Term To-Do List

Archived BS To-Do Items

SR To-Do Items

Every Week

Coming Weeks

Every Week


  • Vacuum and roll floor.
  • Wipe ladders.
  • Tidy tools, parts.
  • Get stuff from ../WishList


(No work Monday 9/18)

Main Assembly Sequence

  • Debug BF LVDT actuation.

  • Check F0 yoke height (top of coil former should be 37.5 mm above bottom of recess in top of baseplate) 36mm.

  • Test all PI items:
    • Yaw stepper (tested, not clearly working).
    • F0 LVDT sensing

    • F0 LVDT actuation

    • Calibrate F0 LVDT.

    • Horizontal LVDT sensing
    • Horizontal LVDT actuation
    • Geophones (issues with driver, cables, descramblers)

  • Lock the F0 and SF keystones and measure the resonance frequency of the BF GAS 2 Measurements: f1=0.443 Hz, f2=0.454 Hz.

  • Lock the SF and BF keystones and measure the resonance frequency of the F0 GAS 2 Measurements: f1=0.208 Hz, f2=0.210 Hz.

  • Double check BS pitch with OL.

  • Adjust SF damper ring to correct gap.

  • Install lock nuts on F0 GAS FR at TBD positions.

  • Lock BF and F0 keystones (but not SF keystone).

  • Lock RM to BS and IRM to IM.
  • Lock RM, IRM and BF (but not SF) to security structure.
  • Lock IP.
  • Remove F0 keystone top plate (including yaw stepper) and immobilize SF/... in yaw.

  • Attach lifting fixture.

  • Remove BF- and SF-level crossbars.
  • Remove geophones for craning.

  • Disconnect in-vacuum cables from feedthrough and coil neatly for craning.
  • Attach lifting plates.

Tank Preparation Sequence

  • Attach Cu segments to LBB damper ring.
  • Pass halves of LBB magnet ring into tank, join, and make sandwich for craning.
  • Crane tank lid off.

  • Crane LBB damper rings to top of tank and suspend.
  • Crane suspension out of assembly frame.
  • Attach LBB upper rods to LBB blade tips and rotate suspension 45° clockwise.
  • Crane suspension into tank and connect upper rods to LBB Cu ring.
  • Unclamp LBB ring "sandwich" so LBB Cu ring is suspended on upper rods.
  • Install LBB lower rods and hook LBB.
  • Measure required ballast for LBB.
  • Unlock suspension and readjust.
  • Move in-air cabling and feedthroughs and reconnect in-vacuum cables (through Cu O-rings).

In parallel, time permitting

  • Fix issue with geophone distributor.

  • Fix #1 geophone adapter cable (and replace borrowed one).
  • Fix broken pico adapter cable.
  • Figure out how to tighten PI yaw return spring or otherwise make yaw adjustment reliable.

Tasks Not To Forget

Major Tasks

  • Update BS Install Procedure with screenshots from new on-assembly-frame 3D CAD.
  • Finish assembly drawing for LBB and LBB damper ring and post on JGWDoc (Hirata-san).
  • Get pico drive screens fixed (Miyo-kun)

Minor Tasks


  • Get clean bag laundered.
  • Put pointy-tipped screw in RM trolley for BS
  • Return/replace borrowed parts:
    • Lock washers for LBB dampers
    • Temporary ballast mass (dog clamps) in BF.
  • Swap in new F0-SF maraging rod (with 8-mm heads) and new receptacles to match.


  • Decide final in-vacuum and in-air cable routing (Enzo).
  • Calibrate all LVDTs (Enzo, Mark). BF, SF, PI-GAS, PI-H1, PI-H2, PI-H3

  • Adjust yoke on PI to put top of secondary at TBD mm above top of baseplate (or to give ≈0 counts at nominal height).

Real-time and SUMCON models

  • Create SUMCON models for full BS and major installation milestones.
  • Create controls design description (cf LIGO-T1100378).

  • Make table of ADC/DAC assignments and check for consistency with D1503600 and k1visbs (Enzo, Mark)
  • Understand/document/debug Kokeyama-san's DIO stuff.
  • Measure LPCD and HPCD output filter response.
  • Design and install software compensation filters for LPCD and HPCD output filters.
  • Design and install GAS drift compensation filters.

KAGRA/Subgroups/VIS/TypeB/ToDoBS (last edited 2019-01-04 15:21:23 by MarkBarton)