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| ==== 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 In the process we noticed and fixed an issue with the assembly frame (due to an out-of-date number in the Mirapro diagram, the IM crossbars were set 3 mm too high, which would have affected the wire length).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. |
==== Report for week of 6/18 ==== * We powered down the Type B racks as a precaution against possible loss of power during work on Tuesday, and later powered them up again. * We put a flange cover over the hole in the floor near the filter tuning area as a temporary safety measure. We later managed to entirely close the part of the hole that was not covered by the filter, by moving the filter towards the outside and using short floor panels from SR2 on the tank side. * We removed the SR3 PI from the filter tuning area and brought in the SR2 one. * We put magnets on the SR damper magnet ring to match the two Cu segments we were using. * We craned the SR3 PI into the AF, connected it to the security structure, and hooked the SF/... section and the SF damper magnet ring. * At first the F0 did not rise, and we realized that we had 2 kg less margin than we originally thought because we had not allowed for the PI-SF rod receptacle, the top disk which holds the yaw stepper mechanism, or the stepper itself. * However we were able to try the redesigned PI fishing rod, parts for which had just arrived. The optional strong CuBe spring in the new arrangement gave plenty of extra lift, so that we now have about 5 kg of margin. We did have to move the yoke to work around the problem that the CuBe spring tends to tilt the keystone, but we got it moving freely. We will also have to compress the blades some more to compensate for the extra stiffness, which caused the frequency to rise from 0.5 Hz to 0.9 Hz. |
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| ==== 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 5/21 ==== * Mark, Enzo, Hirata-san, Kamioka Mon-Fri. * Kozu-kun at Kamioka Wed-Fri. |
==== Plan for week of 7/2 ==== * Mark, Hirata-san, Terrence at Kamioka Mon-Fri. * Enzo at Kamioka Mon-Wed. * Kozu-kun at Kamioka except Wed. * -- * Continued tuning of filter in PI #3 for SR3. * Building and tuning of filter in PI #1 for SR2 (time permitting). * Lots of cable routing and testing. * Install geophones and arc weights. |
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| ==== Plan for week of 5/28 ==== * Mark, Enzo, Hirata-san, Kamioka Mon-Fri. * Kozu-kun at Kamioka Mon only. |
==== Plan for week of 7/9 ==== * Mark, Enzo, Hirata-san, Kozu-kun, Terrence at Kamioka Mon-Fri. * -- * Lock suspension. * Remove tank lid and raise LBB damper rings. * Crane suspension into tank. |
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| * [[KAGRA/Subgroups/VIS/TypeB/March2018]] * [[KAGRA/Subgroups/VIS/TypeB/April2018]] |
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| * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779-v1 Type B Schedule (SR)]] | * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779 Type B Schedule (SR)]] |
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| * Kozu-kun: 7/4 Tokyo. * Enzo: 7/5-6 NAOJ Party, Mitaka. * Terrence: 8/24-26 f2f, then returns to Hong Kong. * Enzo: 9/14 JPS, 9/15 through 10/18 vacation in Chile. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 6/18
- We powered down the Type B racks as a precaution against possible loss of power during work on Tuesday, and later powered them up again.
- We put a flange cover over the hole in the floor near the filter tuning area as a temporary safety measure. We later managed to entirely close the part of the hole that was not covered by the filter, by moving the filter towards the outside and using short floor panels from SR2 on the tank side.
- We removed the SR3 PI from the filter tuning area and brought in the SR2 one.
- We put magnets on the SR damper magnet ring to match the two Cu segments we were using.
- We craned the SR3 PI into the AF, connected it to the security structure, and hooked the SF/... section and the SF damper magnet ring.
- At first the F0 did not rise, and we realized that we had 2 kg less margin than we originally thought because we had not allowed for the PI-SF rod receptacle, the top disk which holds the yaw stepper mechanism, or the stepper itself.
However we were able to try the redesigned PI fishing rod, parts for which had just arrived. The optional strong CuBe spring in the new arrangement gave plenty of extra lift, so that we now have about 5 kg of margin. We did have to move the yoke to work around the problem that the CuBe spring tends to tilt the keystone, but we got it moving freely. We will also have to compress the blades some more to compensate for the extra stiffness, which caused the frequency to rise from 0.5 Hz to 0.9 Hz.
Plan for week of 7/2
- Mark, Hirata-san, Terrence at Kamioka Mon-Fri.
- Enzo at Kamioka Mon-Wed.
- Kozu-kun at Kamioka except Wed.
- --
- Continued tuning of filter in PI #3 for SR3.
- Building and tuning of filter in PI #1 for SR2 (time permitting).
- Lots of cable routing and testing.
- Install geophones and arc weights.
Plan for week of 7/9
- Mark, Enzo, Hirata-san, Kozu-kun, Terrence at Kamioka Mon-Fri.
- --
- Lock suspension.
- Remove tank lid and raise LBB damper rings.
- Crane suspension into tank.
To-Do Lists, Schedule
Vacation Info
- Kozu-kun: 7/4 Tokyo.
- Enzo: 7/5-6 NAOJ Party, Mitaka.
- Terrence: 8/24-26 f2f, then returns to Hong Kong.
- Enzo: 9/14 JPS, 9/15 through 10/18 vacation in Chile.