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At Kamioka (Mark, Fabian, Enzo, Hirata-san):
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 * Inspected LLB in tank - in a good position, but not very clean - apparent water spots and dirt.
 * Found the geophone adapter plates.
 * Retested SF FR stepper - still good.
 * Finally got SF LVDT working:
  * Found a short in the primary coil due to Al foil used for mechanical reinforcement at vacuum feedthrough connection.
  * Did a full calibration and found that linear range was too small (0.75 mm!) and did not cover nominal keystone height.
  * Decreased gain to increase linear range.
  * Adjusted the height of the yoke and secondary coil unit to center the linear region around the nominal keystone height.
  * Implemented velocity damping.
 * Found all parts for the LBB and damper rings.
  * Cu segments and some other parts were very dirty - wiped carefully for now, but should be properly cleaned before final install.
  * Outrigger parts for LBB have M16 thread cut directly into Al but should have had M16 helicoils. This is a galling risk with Ag-coated rod receptacles. Hirata-san organized rework.
  * Some special lock nuts are in short supply and are being borrowed from supply at ATC for next batch of BFs.
 * Made remaining two geophone in-air descrambler cables (total three).
 * Installed a thermometer supplied by Kokeyama-san on the tower around the BS tank.
 * Prepared the SF damper.
  * Designed a pattern of magnets for the two-segment arrangement of SF damper and laid it out on the magnet ring with the template.
  * Moved the Cu segments on SF cap by 30° (the cap had not been in the right position earlier).
 * Reinstalled PI:
  * Raised the PI with the crane and hooked the SF damper ring. Some of the rods did not fit the receptacles due to tolerance issue, but by going through a large number of rods and receptacles, we found three working sets.
  * Craned the PI onto the frame and suspended the SF/... section, this time with the hex cable clamp on the F0-SF rod.
  * Tensioned the PI yaw return spring, installed (but did not cable) the yaw stepper and adjusted the yaw of the SF/... section. We worry the return spring is not stiff enough.
  * Installed (but did not cable) the geophones.
  * Recentered the IP. The extra weight from the geophones (≈42 kg) and SF damper ring (≈17 kg) had brought the IP to near the point of instability, so we removed one arc weight (≈17 kg) and rearranged the other two in the top row to be symmetrical.
  * Added ballast to set the height of the F0 keystone. We now have about 6 kg in hand (due to removing one of the Cu segments for the SF damper). This should be enough margin for cables, temperature fluctuations etc.		  * Mark analyzed the QPD data from Friday 12/1 and derived matrices to diagonalize the QPD, and calibrate output in µrad. In the process an error in the IM OSEM diagonalization was discovered: the P and Y gains were low by a factor 2.
 * Mark re-zeroed the QPD after noting the micrometer readings so we can do TFs over the weekend.
 * We prepared for the SR2 gluing:
  * We aligned the SR2 in the box with the wedge on the correct side.
  * We checked that the remachined BS prism holders fit on the PR2 mirror box.
  * We checked that with Tatsumi-san's support ring, the prisms would go on at the right height.
  * We checked the new magnet jigs.
 * We glued ferromagnetic disks in a large number of IM flag tips and flag bases, and in the SR magnet jigs.
 * We also glued SR magnets in the magnet bases.
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==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].		 ==== Plan for week of 12/11
 * Mark, Fabian, Enzo, Kozu-kun (Mon-Thu only), Hirata-san, Shoda-san at Kamioka.
 * Mirror gluing.
 * IM assembly and pico test.
 * Assembly frame alignment and optical table centering.
 * Move trolley system from SR3.
 * OL setup.
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Week of 5/29, 6/6:
 * Cabling:
  * Route BF/... cabling up past SF to PI.
  * Route SF cabling up to PI.
  * Add Type 3 extensions to SF/... cables.
  * Move vacuum flanges to positions on assembly frame more convenient for next stage (accessible from second floor, one on each corner of frame).
  * Move in-air cabling to match flange positions.
  * Cable and test PI vertical LVDT.
  * Calibrate PI vertical LVDT.
  * Set yoke on PI vertical LVDT (if necessary).
  * Cable and test PI yaw stepper.
  * Cable and test PI vertical stepper.
  * Cable and test PI horizontal steppers.
  * Cable and test PI horizontal LVDTs.
  * Calibrate PI horizontal LVDTs.
 * Crane into tank.		 ==== Plan for week of 12/18 ====
 * Shoda-san vacation
 * Mark, Fabian, Enzo, Kozu-kun at Kamioka Mon-Wed.

==== Vacation Info ====
 * Mark 12/22-1/3
 * Enzo, 12/21-12/27 (but ''not'' 12/28)
 * Fabian 12/22-1/5
 * Hirata-san 12/21-22 (conference)
 * Shoda-san 12/18-21
  

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past week report

  • Mark analyzed the QPD data from Friday 12/1 and derived matrices to diagonalize the QPD, and calibrate output in µrad. In the process an error in the IM OSEM diagonalization was discovered: the P and Y gains were low by a factor 2.
  • Mark re-zeroed the QPD after noting the micrometer readings so we can do TFs over the weekend.
  • We prepared for the SR2 gluing:
    • We aligned the SR2 in the box with the wedge on the correct side.
    • We checked that the remachined BS prism holders fit on the PR2 mirror box.
    • We checked that with Tatsumi-san's support ring, the prisms would go on at the right height.
    • We checked the new magnet jigs.
  • We glued ferromagnetic disks in a large number of IM flag tips and flag bases, and in the SR magnet jigs.
  • We also glued SR magnets in the magnet bases.

==== Plan for week of 12/11

  • Mark, Fabian, Enzo, Kozu-kun (Mon-Thu only), Hirata-san, Shoda-san at Kamioka.
  • Mirror gluing.
  • IM assembly and pico test.
  • Assembly frame alignment and optical table centering.
  • Move trolley system from SR3.
  • OL setup.

Plan for week of 12/18

  • Shoda-san vacation
  • Mark, Fabian, Enzo, Kozu-kun at Kamioka Mon-Wed.

Vacation Info

  • Mark 12/22-1/3

  • Enzo, 12/21-12/27 (but not 12/28)

  • Fabian 12/22-1/5
  • Hirata-san 12/21-22 (conference)
  • Shoda-san 12/18-21

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