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==== Report for week of 4/23 ====
 * We hung the optic and set its pitch. The winch system had a lot of slop in it but the technique of relaxing the wires by lifting the optic on the EQ stops was effective in getting consistent results.
 * We tightened the clamps using a torque wrench, using settings of 5 N.m for the primary clamps and 20 N.m for the secondary.
 * We hung the RM and set its pitch. The RM winches were a lot more consistent.
 * However when tightening the clamps, the wire on the +Y side broke at the bottom edge of primary clamp. The wire on the -Y held, so the RM dropped a few mm onto the trolley on the +Y side.
 * We raised the RM trolley to support the RM and left the optic hanging inside it overnight as a safety test.
 * We then reversed the usual installation procedure to remove the RM and get the mirror box around the optic. We used clamp pieces as spacers to bridge the gaps created by the fact that the optic had been raised 3 mm during hanging and could not safely be lowered. We then cut the wires, leaving the op

==== Plan for week of 4/30 ====
 * Shoda-san at Mitaka.
 * Mark, Enzo at Kamioka Mon-Wed or TBD.
 * Others having fun doing Golden Week stuff.
 * --
 * Observe KAGRA Phase 1 operations, assist if problems arise.
 * Do BF TFs.
 * Continue SR3 hang.

==== Plan for week of 5/7 ====
 * Shoda-san at Mitaka.
 * Hirata-san at Kamioka Mon-Wed, then Mitaka.
 * Kozu-kun at Kamioka Wed-Fri (but may be working with PEM on Fri).
 * Others (Mark, Enzo, Tanioka-kun) at Kamioka full week
 * --
 * Continue SR3 Hang
  * Inspect clamps and decide whether to reuse or swap in clamps from SRM IM.
  * Rehang optic.
  * Rehang RM.
  * Cable RM OSEMs.
 * Prepare for filter testing
  * Remove cracked blades from F0 #1 and #3.
  * Remove floor panel in SR3 area.
  * Set up filter building trolley with crossbars, jacks and F0 test masses.
 
 * Etc
  * Test prototype SR3 safety bar, and set up second safety bar.
  * Negotiate with Mirapro to get SRM mushroom installed, avoiding 5/15.
==== 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 ====
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]]
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoSR]]
 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779 Type B Schedule (SR)]]
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==== To-Do Lists, Schedule ====
 * [[KAGRA/Subgroups/VIS/TypeB/March2018]]
 * [[KAGRA/Subgroups/VIS/TypeB/April2018]]
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]]
 * [[KAGRA/Subgroups/VIS/TypeB/ToDoSR]]
 * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779-v1 Type B Schedule (SR)]]

==== Vacation Info ====
 * Fabian vacation, 3/26-4/27 (then gone).
==== 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.

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