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Size: 3633
Comment:
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Size: 2949
Comment:
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| Deletions are marked like this. | Additions are marked like this. |
| Line 8: | Line 8: |
* 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. |
* Hirata-san and Sekine-san moved the tank lid and service port ring to the pallet with the crane and covered the open tank with the spare clean bag. * Hirata-san and Mark got the LBB damper rings assembled and installed. A joint part for the Cu ring needed to have holes enlarged because the hole pattern did not quite match that on the half-ring. The magnet ring is hanging in the chamber and the Cu ring is attached below it with clamps, ready to receive the rods that will hang down from the PI. * Hirata-san recounted all the unused cables. * Hirata-san installed the outrigger parts on the LBB, which will receive the rods coming down from the damper ring. * Enzo and Mark tested all the stepper motors. * Enzo and Mark debugged the PI horizontal LVDTs. One LVDT had a flaky connection and one card in the LVDT driver had three dead channels. Enzo created a fully working driver using parts from another driver that also had a faulty card. * Fabian adjusted the ballast mass on the SF to get good pitch/roll/vertical adjustment and attached it with screws. * Fabian set up the optical lever again (the PR2 team had repossessed the breadboard we had been using but Akutsu-san supplied another one). * Enzo and Mark tested the pico motors. The software is very unreliable, but we we able to confirm that the IM pitch pico works. * The whole team wrapped items and shut down equipment ahead of the power outage. |
| Line 38: | Line 21: |
| Week of 5/29, 6/6: | Week of 6/12: |
| Line 40: | Line 23: |
| * 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. |
* Debug/fix PI vertical LVDTs #0 and #2. |
| Line 47: | Line 25: |
| * Debug/fix geophone #1. | |
| Line 53: | Line 32: |
| * Crane into tank. | * Prepare LBB. * Attach LBB outriggers and rod receptacles. * Prepare LBB Cu ring. * Remove from tank, fix incompletely threaded holes, reinstall in tank. * Lay down spacers to protect magnets (in next step). * Prepare LBB magnet ring. * Disassemble. * Pass pieces into tank. * Reassemble on top of Cu ring. * Install LBB damper. * Bind LBB damper rings together with slings. * Remove vacuum tank lid and ring. * Crane rings up to install height, hook LBB magnet ring and support LBB Cu ring by TBD method. * Crane suspension into tank. * Hook LBB Cu ring. * Hook LBB. * Crane vacuum tank lid+ring black on. * Remove vacuum tank lid (only). * Remove port covers where feedthroughs will go, move feedthroughs from assembly frame and install on vacuum tank ring. * Reconnect in-air cables. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past week report
At Kamioka (Mark, Fabian, Enzo, Hirata-san):
- Hirata-san and Sekine-san moved the tank lid and service port ring to the pallet with the crane and covered the open tank with the spare clean bag.
- Hirata-san and Mark got the LBB damper rings assembled and installed. A joint part for the Cu ring needed to have holes enlarged because the hole pattern did not quite match that on the half-ring. The magnet ring is hanging in the chamber and the Cu ring is attached below it with clamps, ready to receive the rods that will hang down from the PI.
- Hirata-san recounted all the unused cables.
- Hirata-san installed the outrigger parts on the LBB, which will receive the rods coming down from the damper ring.
- Enzo and Mark tested all the stepper motors.
- Enzo and Mark debugged the PI horizontal LVDTs. One LVDT had a flaky connection and one card in the LVDT driver had three dead channels. Enzo created a fully working driver using parts from another driver that also had a faulty card.
- Fabian adjusted the ballast mass on the SF to get good pitch/roll/vertical adjustment and attached it with screws.
- Fabian set up the optical lever again (the PR2 team had repossessed the breadboard we had been using but Akutsu-san supplied another one).
- Enzo and Mark tested the pico motors. The software is very unreliable, but we we able to confirm that the IM pitch pico works.
- The whole team wrapped items and shut down equipment ahead of the power outage.
Plan for coming weeks
For more detail, see KAGRA/Subgroups/VIS/TypeB/ToDo.
Week of 6/12:
- Cabling:
- Debug/fix PI vertical LVDTs #0 and #2.
- Calibrate PI vertical LVDT.
- Debug/fix geophone #1.
- 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.
- Prepare LBB.
- Attach LBB outriggers and rod receptacles.
- Prepare LBB Cu ring.
- Remove from tank, fix incompletely threaded holes, reinstall in tank.
- Lay down spacers to protect magnets (in next step).
- Prepare LBB magnet ring.
- Disassemble.
- Pass pieces into tank.
- Reassemble on top of Cu ring.
- Install LBB damper.
- Bind LBB damper rings together with slings.
- Remove vacuum tank lid and ring.
- Crane rings up to install height, hook LBB magnet ring and support LBB Cu ring by TBD method.
- Crane suspension into tank.
- Hook LBB Cu ring.
- Hook LBB.
- Crane vacuum tank lid+ring black on.
- Remove vacuum tank lid (only).
- Remove port covers where feedthroughs will go, move feedthroughs from assembly frame and install on vacuum tank ring.
- Reconnect in-air cables.