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 * Type B Past Week Summary
  * Mark and Fabian worked at Kamioka with Fujii-san:
   * We attempted to measure the tilt sensitivity of the accelerometers by adding shims under the legs but gave up when we discovered that picking up and putting down the accelerometer perturbs the zero point even without shims. We will probably need a special tilt stage to do this properly.
   * We took some frequency and Q measurements. The results were amplitude dependent. Joris thinks that this is due to not operating the accelerometers close enough to zero DC output.
   * We set up for a test of the geophone noise. One geophone is reading half the output of the others - one of the adapter cables is broken.
  * Hirata-san:
   * Received extra compensation masses and washed them.
   * Received PI guides, assembled them and shipped them to Kamioka.
   * Received backup set of pillar for security structure (with M10 instead of M12 holes at top).
   * Removed adhesive from base of BS flags in preparation for regluing.
   * Did assembly drawings for cable clamps and other add-on parts for BF and SF.
 * Type B ongoing issues
  * Wires
   * Need to decide RM wire thickness and order BS and RM wires. Lead time is a few days from Nilaco.
  * OSEMs
   * Akutsu-san is working to get wide-mouth OSEMs
  * Longer cables for BF->PI and SF->PI.
   * Connectors RECEIVED, cables being made.
  * Feedthrough Adapters
   * Connectors RECEIVED.
  * SR machining test ONGOING.
  * Installation stuff
   * "Ceiling" work in BS clean booth (removal of second floor section) scheduled for Fri 7/1.
   * Assembly frame construction scheduled for 7/4
  * Ballast masses for payload
   * Initial batch received - ordered extra smaller ones to allow for adjustments.
  * Lower breadboard stuff
   * Installation to be incorporated into the procedure document. Mark/Takahashi to discuss.
   * Breadboard springs (in manufacture, expected end of July)
   * Nail-head parts - ordered with assembly frame, will arrive next week.
  * Documents
   * BS Assembly Procedure [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4235| E1504235]], [[https://onedrive.live.com/redir?resid=D5CCFA70A378E0D0!195&authkey=!AM_usynuo9QI57g&ithint=folder,webloc|E1504235 draft]]
=== 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 ====
 * [[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)]]


==== 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)