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==== 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.
==== Report for week of 7/2 ====
 * We double-checked the bounce frequency and it was indeed around 0.5 Hz with the CuBe auxiliary spring installed.
 * We prepared (but did not yet install) 6 arc weights for tuning the IP.
 * We unlocked the security structure from the assembly frame, and raised the whole system on the top jacks. We then unlocked the IP and adjusted the leveling so the IP was centered. We then had to loosen two of the poles at the top level of the security structure to make it vertical again, because it turns out that the jack receptacles (which also serve as the IP leg bases) are welded at very uneven depths in the bottom surface of the PI, so the IP and the bottom surface can't be level at once.
 * We debugged an issue with the height of the payload. It turns out that due to a buildup of errors (especially an extra 3 mm between the SF and BF), the payload is some 5-6 mm low with the F0 keystone at CAD height. Since the frequency is roughly independent of height around 0.5 Hz, we decided to go with a higher F0 keystone.
 * Enzo and Eleonora routed all the SF/... cables up to the PI.
 * We found we needed 4.7 kg of extra mass to get the desired keystone height, so we decided to put the third Cu segment (3.3 kg) back on, purely as ballast.
 * We put some extra small masses on the SF cap to level it. The suspension is now fully ballasted and trimmed except for 1 Promec mass (455 g) standing in for the new PI yaw stepper motor assembly (estimated 330 g) which is yet to arrive.
 * We took all the SR sat amps back to Mozumi to get new capacitors installed, and grabbed three spares for use while that is being done.
 * We investigated and documented Tanaka-san's watchdog for the BS, to see if the BIO Converter chassis that it uses could also drive reset lines for stepper motor driver boxes.
 * Hirata-san and Terrence characterized the last 4 F0 blades.
 * Hirata-san and Terrence installed blades in the top filter for SR2 and tuned it to 0.5 Hz (with the CuBe auxiliary spring) over three rounds of compression.
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==== 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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===== Main Sequence =====
 * Check/restore alignment of payload, especially optic pitch.
 * Install and cable geophones.
 * Install arc weights.
 * Tune IP.
 * Install, cable PI yaw stepper.
 * Make three in-air stepper splitter cables for SR2, SR3 and SRM.
 * Calibrate PI LVDTs and FRs.
 * Cabling, testing, TFs.

===== F0/LBB Stuff ====
 * Finalize PI #1 for SR2; crane into SR2 cleanbooth.
 * Remove SR3 tank lid, crane LBB rings to top of lower half of the tank, clamp in position.
 * Set tank jacks to nominal height.
 * Clear space for PI #2 (SRM) work.

=== Plan for week of 7/16 ===
===== Main Sequence =====
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 * Remove tank lid and raise LBB damper rings.
 * Crane suspension into tank.
 * Crane into tank.
 * Unlock suspension.
 * Rearrange cables.
 * Test.
===== F0/LBB Stuff =====
 * Install correct IP in PI #2.
 * Crane PI #2 to second floor.
 * Rebuild top filter of PI #2.
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 * Kozu-kun: 7/4 Tokyo.
 * Enzo: 7/5-6 NAOJ Party, Mitaka.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 7/2

  • We double-checked the bounce frequency and it was indeed around 0.5 Hz with the CuBe auxiliary spring installed.

  • We prepared (but did not yet install) 6 arc weights for tuning the IP.
  • We unlocked the security structure from the assembly frame, and raised the whole system on the top jacks. We then unlocked the IP and adjusted the leveling so the IP was centered. We then had to loosen two of the poles at the top level of the security structure to make it vertical again, because it turns out that the jack receptacles (which also serve as the IP leg bases) are welded at very uneven depths in the bottom surface of the PI, so the IP and the bottom surface can't be level at once.
  • We debugged an issue with the height of the payload. It turns out that due to a buildup of errors (especially an extra 3 mm between the SF and BF), the payload is some 5-6 mm low with the F0 keystone at CAD height. Since the frequency is roughly independent of height around 0.5 Hz, we decided to go with a higher F0 keystone.
  • Enzo and Eleonora routed all the SF/... cables up to the PI.
  • We found we needed 4.7 kg of extra mass to get the desired keystone height, so we decided to put the third Cu segment (3.3 kg) back on, purely as ballast.
  • We put some extra small masses on the SF cap to level it. The suspension is now fully ballasted and trimmed except for 1 Promec mass (455 g) standing in for the new PI yaw stepper motor assembly (estimated 330 g) which is yet to arrive.
  • We took all the SR sat amps back to Mozumi to get new capacitors installed, and grabbed three spares for use while that is being done.
  • We investigated and documented Tanaka-san's watchdog for the BS, to see if the BIO Converter chassis that it uses could also drive reset lines for stepper motor driver boxes.
  • Hirata-san and Terrence characterized the last 4 F0 blades.
  • Hirata-san and Terrence installed blades in the top filter for SR2 and tuned it to 0.5 Hz (with the CuBe auxiliary spring) over three rounds of compression.

Plan for week of 7/9

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

Main Sequence
  • Check/restore alignment of payload, especially optic pitch.
  • Install and cable geophones.
  • Install arc weights.
  • Tune IP.
  • Install, cable PI yaw stepper.
  • Make three in-air stepper splitter cables for SR2, SR3 and SRM.
  • Calibrate PI LVDTs and FRs.
  • Cabling, testing, TFs.

===== F0/LBB Stuff ====

  • Finalize PI #1 for SR2; crane into SR2 cleanbooth.
  • Remove SR3 tank lid, crane LBB rings to top of lower half of the tank, clamp in position.
  • Set tank jacks to nominal height.
  • Clear space for PI #2 (SRM) work.

Plan for week of 7/16

Main Sequence
  • Lock suspension.
  • Crane into tank.
  • Unlock suspension.
  • Rearrange cables.
  • Test.

F0/LBB Stuff
  • Install correct IP in PI #2.
  • Crane PI #2 to second floor.
  • Rebuild top filter of PI #2.

To-Do Lists, Schedule

Vacation Info

  • Terrence: 8/24-26 f2f, then returns to Hong Kong.
  • Enzo: 9/14 JPS, 9/15 through 10/8 vacation in Chile.

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-01-14 13:44:05 by fabian.arellano)