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← Revision 200 as of 2017-10-13 14:57:07 → ⇥
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Deletions are marked like this. Additions are marked like this.
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At Kamioka (Mark, Fabian, Enzo, Hirata-san): At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Kozu-kun):
 * We couldn't account for a bubble level, so we removed a service port cover, searched again on top of the BF and found it.
 * We put the table KOACH filters on the table. Ohishi-san then removed the FC in two stages (AR side on Tue, HR side on Fri).
 * Ohishi-san measured the height of the SS and optic relative to the tank and found the optic was 3 mm low but the SS was 2 mm high. According to the GAS LVDTs, the suspension had not sagged but was 1.7 mm high.
 * Therefore we raised the suspension by 9 quarter-turns of the tank jacks (4.5 mm) so that the optic would be in the right position after (future) downward adjustment of the GAS filters.
 * We put the GAS LVDT calibration data as offsets and gains in the LVDTINF filters so the output would be height in µm relative to nominal.
 * We calibrated the IP LVDTs. We had worked around a mechanical interference due to the poor design of the old LVDTs by setting them to be 4 mm off-center with the IP locked centrally, but we discovered this was overkill and we have lost some linear range on the LVDT sensor in the opposite direction. If we have time we may move the LVDT bases 1-2 mm to a compromise position.
 * We worked with Simon to get the OL aligned and to learn the adjustment procedure.
 * Mark updated Sekiguchi-san's SUMCON to allow for comments to be entered next to all values (75% finished).
 * Kozu-kun worked on deriving the diagonalization matrices for the IP FRs.
 
At Mitaka (Hirata-san):
 * Hirata-san met with manufacturers and requested quotes.
 * Hirata-san made many assembly drawings for sections of the SR.
 * Hirata-san worked on compiling the SR inventory.
Line 9: Line 23:
 * 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.		 ==== Plan for week of 10/16 ====
Kamioka: all but Mark
 * Remove sticker residue and permanent marker writing on PI.
 * Fix broken and unreliable connections on IP LVDTs.
 * Wipe any rust from around IP LVDTs.
 * (If Enzo thinks it necessary and there's time) adjust IP LVDT mechanical offsets to maximize usable range and recalibrate.
 * Add IP LVDT gains and offsets to IP_LVDTINF filter blocks.
 * Calibrate IP LVDT actuation against IP LVDT sensing.
 * Install damping filters for IP LVDTs.
 * Adjust gains and debug damping for IM OSEMs and GAS LVDTs.
 * Modify IP LVDT damping filters to include set point.
 * Install and debug IP LVDT and geophone diagonalization matrices.
 * (Time permitting) Try adding mass to IP.
 * Work with alignment team.
 * Work with Mirapro on SR LBB and tank installation (Hirata-san, from Wed)
 * Work with Miyo-kun to get user interface for stepper motors.
 * Calibrate IP FR actuation against IP LVDT sensing.
 * SR procurement.
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==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].

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.		 ==== Vacation Info ====
Mark: 10/16-24

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past week report

At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Kozu-kun):

  • We couldn't account for a bubble level, so we removed a service port cover, searched again on top of the BF and found it.
  • We put the table KOACH filters on the table. Ohishi-san then removed the FC in two stages (AR side on Tue, HR side on Fri).
  • Ohishi-san measured the height of the SS and optic relative to the tank and found the optic was 3 mm low but the SS was 2 mm high. According to the GAS LVDTs, the suspension had not sagged but was 1.7 mm high.
  • Therefore we raised the suspension by 9 quarter-turns of the tank jacks (4.5 mm) so that the optic would be in the right position after (future) downward adjustment of the GAS filters.
  • We put the GAS LVDT calibration data as offsets and gains in the LVDTINF filters so the output would be height in µm relative to nominal.
  • We calibrated the IP LVDTs. We had worked around a mechanical interference due to the poor design of the old LVDTs by setting them to be 4 mm off-center with the IP locked centrally, but we discovered this was overkill and we have lost some linear range on the LVDT sensor in the opposite direction. If we have time we may move the LVDT bases 1-2 mm to a compromise position.
  • We worked with Simon to get the OL aligned and to learn the adjustment procedure.
  • Mark updated Sekiguchi-san's SUMCON to allow for comments to be entered next to all values (75% finished).
  • Kozu-kun worked on deriving the diagonalization matrices for the IP FRs.

At Mitaka (Hirata-san):

  • Hirata-san met with manufacturers and requested quotes.
  • Hirata-san made many assembly drawings for sections of the SR.
  • Hirata-san worked on compiling the SR inventory.

Plan for week of 10/16

Kamioka: all but Mark

  • Remove sticker residue and permanent marker writing on PI.
  • Fix broken and unreliable connections on IP LVDTs.
  • Wipe any rust from around IP LVDTs.
  • (If Enzo thinks it necessary and there's time) adjust IP LVDT mechanical offsets to maximize usable range and recalibrate.
  • Add IP LVDT gains and offsets to IP_LVDTINF filter blocks.
  • Calibrate IP LVDT actuation against IP LVDT sensing.
  • Install damping filters for IP LVDTs.
  • Adjust gains and debug damping for IM OSEMs and GAS LVDTs.
  • Modify IP LVDT damping filters to include set point.
  • Install and debug IP LVDT and geophone diagonalization matrices.
  • (Time permitting) Try adding mass to IP.
  • Work with alignment team.
  • Work with Mirapro on SR LBB and tank installation (Hirata-san, from Wed)
  • Work with Miyo-kun to get user interface for stepper motors.
  • Calibrate IP FR actuation against IP LVDT sensing.
  • SR procurement.

Vacation Info

Mark: 10/16-24

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