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Revision 235 as of 2018-02-16 11:18:11
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Revision 283 as of 2018-05-11 11:35:38
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Deletions are marked like this. Additions are marked like this.
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==== Report for week of 1/29 ====
 * Fabian and Kozu-kun tested the FR stepper, and calibrated the keystone height as a function of FR position.
 * Fabian, Hirata-san and Kozu-kun installed and adjusted the IRM, IM OSEMs and associated cables.
 * Mark derived the diagonalization matrices for SR, posted them as [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7663| T1807663]] and entered them in the on-line system.
 * Mark fixed the GASALL screen, which had some elements hardwired to BS and did not work for SR2.
 * Mark initialized the watchdog section of the SR2 model (filters, thresholds etc).
 * Mark re-entered the IM OSEM2EUL offsets and gains, which had been entered by Enzo, but had not been saved and had been lost.
 * Mark identified and fixed a bug in the SF2 whereby the watchdog trigger was derived from the AND of the error signals from the various stages instead of the OR. Thus all stages would have to overload before the watchdog tripped. All other VIS models were similarly affected, and all affected library parts have been fixed, but the other models need to be rebuilt, which should be done at the earliest opportunity, e.g., early next week after the scheduled power outage on Sun 2/18.
 * Mark fixed the indicators for the watchdog on the OVERALL screen, which also had bad logic.
 * Mark tried using Shoda-san's measurement script to do TFs. It ran successfully, but the first data set was no good because of two issues: the excitation was apparently too large (even after a reduction by 20) and the SENSALIGN matrix was not initialized.
 * Hirata-san negotiated with Kimura-san to get the SRM tank mushroom installed (this will probably happen from Tue on the week of 3/5).
==== Report for week of 5/7 ====
 * We inspected the wires and clamps involved in the wire break.
  * The scars on the clamp on the tungsten wire that failed had very different depths, with the one that failed being much deeper, so probably the clamp piece was not completely straight before tensioning. However one wire on the other side was also badly crushed and on the point of failing, so the tension was clearly too much.
  * We decided on new torque specs of 2 N.m for the primary clamps (down from 5 N.m) and 10 N.m (down from 20 N.m) for the secondary. The secondary clamp spec, for M6 screws, is now based on the LIGO policy of using the maximum suggested for the screw and the LIGO value for a coated 1/4-20 screw (100 in-lb = 11.3 N.m), and the primary clamp spec is derated by 2/3 from the spec for an M5 screw because the clamp pieces are recessed and only grip the wire at narrow sections along the edges, concentrating the force.
  * None of the screws showed any signs of damage.
  * All of the scars on the primary clamps were shallow enough that could reuse the clamp pieces. The tungsten secondary clamps were never tightened, and the outer pieces of piano wire secondary clamps were badly scarred but could be reused upside down.
 * We successfully rehung the SR3 and RM. In the process we noticed and fixed an issue with the assembly frame (due to an out-of-date number in the Mirapro diagram, the IM crossbars were set 3 mm too high, which would have affected the wire length).
 * We added the sections of the security structure below the RM and up to the BF.
 * We installed the TM OSEM cables and routed them up to the IM.
 * We installed the load gauge adapter and load gauge and prepared the IM/... section for weighing.
 * We removed the three cracked F0 blades from the PI #3 in the SRM, and prepared for testing prototype new blades in that PI. We removed a floor panel under the PI and set up the filter service trolley underneath it with a stack of masses for a dummy load.
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==== Plan for week of 2/19 ====
 * Enzo back from Tuesday.
 * Shoda-san at Mitaka.
 * Hirata-san at Mitaka Mon+Tue (to receive and wash parts).
 * All others at Kamioka.
 * -
 * Do TFs from IM OSEMs to IM OSEMs, OL pitch/yaw.
 * Lift BF/... section and check total mass and balance.
 * Cable and test BF picos.
 * Add section of SS up to SF ring.
 * Bring in SF.
 * Hook BF/... section.
 * Route cables up to under SF.
 * Check/adjust total mass of BF/... section.
==== Plan for week of 5/14 ====
 * Mark, Enzo, Hirata-san, Kozu-kun at Kamioka Mon-Thu, then Osaka.
 *
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==== Plan for week of 2/26 ====
 * Shoda-san at Mitaka.
 * -
 * Add Cu segments to SF cap.
 * Lift SF/... section and check total mass and balance.
==== Plan for week of 5/21 ====
 * Mark, Enzo, Hirata-san, Kamioka Mon-Fri.
 * Kozu-kun at Kamioka Wed-Fri.
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==== Plan for week of 5/28 ====
 * Mark, Enzo, Hirata-san, Kamioka Mon-Fri.
 * Kozu-kun at Kamioka Mon only.
 
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 * [[KAGRA/Subgroups/VIS/TypeB/April2018]]
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 * Enzo 1/30-2/19.
 * Fabian 4/2-4/27 vacation (then gone).

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 5/7

  • We inspected the wires and clamps involved in the wire break.
    • The scars on the clamp on the tungsten wire that failed had very different depths, with the one that failed being much deeper, so probably the clamp piece was not completely straight before tensioning. However one wire on the other side was also badly crushed and on the point of failing, so the tension was clearly too much.
    • We decided on new torque specs of 2 N.m for the primary clamps (down from 5 N.m) and 10 N.m (down from 20 N.m) for the secondary. The secondary clamp spec, for M6 screws, is now based on the LIGO policy of using the maximum suggested for the screw and the LIGO value for a coated 1/4-20 screw (100 in-lb = 11.3 N.m), and the primary clamp spec is derated by 2/3 from the spec for an M5 screw because the clamp pieces are recessed and only grip the wire at narrow sections along the edges, concentrating the force.
    • None of the screws showed any signs of damage.
    • All of the scars on the primary clamps were shallow enough that could reuse the clamp pieces. The tungsten secondary clamps were never tightened, and the outer pieces of piano wire secondary clamps were badly scarred but could be reused upside down.
  • We successfully rehung the SR3 and RM. In the process we noticed and fixed an issue with the assembly frame (due to an out-of-date number in the Mirapro diagram, the IM crossbars were set 3 mm too high, which would have affected the wire length).
  • We added the sections of the security structure below the RM and up to the BF.
  • We installed the TM OSEM cables and routed them up to the IM.
  • We installed the load gauge adapter and load gauge and prepared the IM/... section for weighing.
  • We removed the three cracked F0 blades from the PI #3 in the SRM, and prepared for testing prototype new blades in that PI. We removed a floor panel under the PI and set up the filter service trolley underneath it with a stack of masses for a dummy load.

Plan for week of 5/14

  • Mark, Enzo, Hirata-san, Kozu-kun at Kamioka Mon-Thu, then Osaka.

Plan for week of 5/21

  • Mark, Enzo, Hirata-san, Kamioka Mon-Fri.
  • Kozu-kun at Kamioka Wed-Fri.

Plan for week of 5/28

  • Mark, Enzo, Hirata-san, Kamioka Mon-Fri.
  • Kozu-kun at Kamioka Mon only.

To-Do Lists, Schedule

Vacation Info

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)