|
Size: 3427
Comment:
|
Size: 3540
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 6: | Line 6: |
| ==== 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 In the process we noticed and fixed an issue with the assembly frame (due to an out-of-date number in the Mirapro diagram, the IM crossbars were set 3 mm too high, which would have affected the wire length).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. * Mirapro installed the SRM mushroom. ==== Plan for week of 5/14 ==== * Mark, Enzo, Hirata-san, Kozu-kun at Kamioka Mon-Thu, then Osaka. * Weigh IM/... section. * Characterize F0 blade prototypes. * Remove F0 blade prototypes (and send for rework if necessary). * Start characterizing LBB blades. * Crane in BF. * Add IRM top plate, maraging rod, flying saucer. * Suspend IM, check pitch, roll and vertical, adjust trim mass. * Cable and (re-)test TM OSEMs, IM picos, BF yaw pico, BF LVDT and FR. ==== Plan for week of 5/21 ==== * Mark, Enzo, Hirata-san, Kamioka Mon-Fri. * Kozu-kun at Kamioka Wed-Fri. * Install IRM sides, and IM OSEMs. * Center IM OSEMs (in/out and laterally) * Route all cables to underneath BF. * Add BF internal ballast mass. * Add BF cap. ==== Plan for week of 5/28 ==== * Mark, Enzo, Hirata-san, Kamioka Mon-Fri. * Kozu-kun at Kamioka Mon only. * TBD. |
==== Report for week of 11/19 ==== * BS * Fabian did some debugging on the BS and found that the calibration for the F0 LVDT was off due to an Excel error, and that the sag wasn't quite the 7 mm originally observed, but still enough to cause the suspension to touch down. Enzo tried applying LVDT actuation at the GAS filters and got it to lift off far enough to get sensible TFs, but the required BF offset was enough to put the IM OSEMs at the very edge of their usable range, so this is not a good long-term solution. We can probably raise the F0 keystone during the vent by removing mass and/or installing an auxiliary spring, which will then allow us to return the BF keystone to nominal height. * While working on the BS, Enzo noticed that one of the stepper drivers was not responding. It turned out to be water damaged from the rain issues earlier in the year. Enzo and Fujii-kun opened the rest of the BS chassises on the second floor but they seem to be OK. Tanaka-san had made a third driver chassis as a spare, so we reserved that and will install it in the week of 12/10. * SRM * The SRM-W optic arrived and we installed it in place of the SRM-M in the metal mass, taking care to use 1.4 mm shims as recommended by Hirose-san. The weight of the new assembly was within 1 g of the old and did not disturb the height of the payload. There was a very small change in pitch which we corrected with the IM picos. * We installed the shelf for the OL receiver. * We added the arc weights and geophones and went through several rounds of improving the centering of the IP and then realigning the security structure back to vertical. * We calibrated the F0 LVDT, and checked the F0 and IP actuation signs. * We adjusted the SF trim masses to set the SF pitch and roll, did an inventory of the trim mass and set the damper gap. * We did a final alignment of the whole chain and left the suspension ready for TFs during the f2f week. There is only a few hours of work left before we can install and we hope to do that on Monday 12/10. * SR2 * Enzo replaced the geophones and cables that had been borrowed for calibration and did several rounds of optimization of the IP frequency. He got as low as 46 mHz but with poor Q and so backed off a bit to 55 mHz and may back off a tiny bit more. * I derived updated IP matrices for the BS and SR, with more precise geometry data provided by Hirata-san, and published them as T1707205 and T1807663. * I created a CENTERING screen for the IP, with large panel meters for the LVDT signals and the derived L, T and Y signals. * Enzo confirmed that the fancy stepper control screen created by Shoda-san worked. * We installed a modified LPCD as IM-V for testing. * SR3 * We moved HPCDs from BS and SR2 to replace the ones that had been stolen from SR3, so as to create a working suspension with an OL for Kozu-kun. |
| Line 44: | Line 26: |
| * [[KAGRA/Subgroups/VIS/TypeB/March2018]] * [[KAGRA/Subgroups/VIS/TypeB/April2018]] |
|
| Line 48: | Line 28: |
| * [[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)]] |
| Line 50: | Line 30: |
| ==== Vacation Info ==== | ==== Plan for week of 12/3 ==== * f2f Meeting at NAOJ - no Kamioka work. ==== Plan for week of 12/10 ==== * Crane SRM into tank. * Install new F0 yaw mechanisms on SRs. * Remove First Contact from SRM, unlock and realign. * Move SRM in-air cables over. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 11/19
- BS
- Fabian did some debugging on the BS and found that the calibration for the F0 LVDT was off due to an Excel error, and that the sag wasn't quite the 7 mm originally observed, but still enough to cause the suspension to touch down. Enzo tried applying LVDT actuation at the GAS filters and got it to lift off far enough to get sensible TFs, but the required BF offset was enough to put the IM OSEMs at the very edge of their usable range, so this is not a good long-term solution. We can probably raise the F0 keystone during the vent by removing mass and/or installing an auxiliary spring, which will then allow us to return the BF keystone to nominal height.
- While working on the BS, Enzo noticed that one of the stepper drivers was not responding. It turned out to be water damaged from the rain issues earlier in the year. Enzo and Fujii-kun opened the rest of the BS chassises on the second floor but they seem to be OK. Tanaka-san had made a third driver chassis as a spare, so we reserved that and will install it in the week of 12/10.
- SRM
- The SRM-W optic arrived and we installed it in place of the SRM-M in the metal mass, taking care to use 1.4 mm shims as recommended by Hirose-san. The weight of the new assembly was within 1 g of the old and did not disturb the height of the payload. There was a very small change in pitch which we corrected with the IM picos.
- We installed the shelf for the OL receiver.
- We added the arc weights and geophones and went through several rounds of improving the centering of the IP and then realigning the security structure back to vertical.
- We calibrated the F0 LVDT, and checked the F0 and IP actuation signs.
- We adjusted the SF trim masses to set the SF pitch and roll, did an inventory of the trim mass and set the damper gap.
- We did a final alignment of the whole chain and left the suspension ready for TFs during the f2f week. There is only a few hours of work left before we can install and we hope to do that on Monday 12/10.
- SR2
- Enzo replaced the geophones and cables that had been borrowed for calibration and did several rounds of optimization of the IP frequency. He got as low as 46 mHz but with poor Q and so backed off a bit to 55 mHz and may back off a tiny bit more.
- I derived updated IP matrices for the BS and SR, with more precise geometry data provided by Hirata-san, and published them as T1707205 and T1807663.
- I created a CENTERING screen for the IP, with large panel meters for the LVDT signals and the derived L, T and Y signals.
- Enzo confirmed that the fancy stepper control screen created by Shoda-san worked.
- We installed a modified LPCD as IM-V for testing.
- SR3
- We moved HPCDs from BS and SR2 to replace the ones that had been stolen from SR3, so as to create a working suspension with an OL for Kozu-kun.
To-Do Lists, Schedule
Plan for week of 12/3
- f2f Meeting at NAOJ - no Kamioka work.
Plan for week of 12/10
- Crane SRM into tank.
- Install new F0 yaw mechanisms on SRs.
- Remove First Contact from SRM, unlock and realign.
- Move SRM in-air cables over.