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Size: 3286
Comment:
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Size: 1396
Comment:
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| Deletions are marked like this. | Additions are marked like this. |
| Line 7: | Line 7: |
| At Kamioka (Mark, Fabian, Enzo, Hirata-san): | |
| Line 9: | 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. |
* Mark worked on SR2 planning. * Mark thought through what would be required to swap an optic (e.g., SRM) in situ (JGW-T1707436). * Hirata-san tried removing disks from IM flags (so we could reuse them in flag bases and make a complete set for SR2) but only got 1 of 4 out. * Hirata-san ordered more disks for IM flags. * Hirata-san asked for quotes on SF LBB blades. * Hirata-san got a reduced quote for the LBB damper rings. * Hirata-san received and cleaned suspension wires for the SR. * Fabian worked on the SR mass budget. * Fabian worked out the COM of the SR2 optic, and Mark used it to derive the proper prism positions. * Enzo and Kozu-kun worked on control filter design and installation. |
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| ==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 11/27 ==== * Fabian at commissioning workshop * Hirata-san at Kamioka Tue-Fri to work with Mirapro on SRM LBB installation. * All others (Mark, Enzo, Shoda-san, Kozu-kun) at Kamioka to start SR2 assembly. * Mark from Mon lunchtime. * Kozu-kun from Mon lunchtime through Wed. * Mirror gluing. * SR2 rack setup. |
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| Weeks of 5/22, 5/29: * Retest SF stepper every day, to see if problems recur. * Find/install geophone adapter plates or improvise replacement. * Reinstall PI, this time with rods and damper ring. * Reinstall PI-SF rod, this time with hex cable clamp. * Cable/test PI geophones LVDTs and steppers. * Reinstall LBB blade units. |
==== Plan for week of 12/4 ==== * All at Kamioka * IM assembly and pico test. * Assembly frame alignment and optical table centering. * OL setup. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past week report
- Mark worked on SR2 planning.
- Mark thought through what would be required to swap an optic (e.g., SRM) in situ (JGW-T1707436).
- Hirata-san tried removing disks from IM flags (so we could reuse them in flag bases and make a complete set for SR2) but only got 1 of 4 out.
- Hirata-san ordered more disks for IM flags.
- Hirata-san asked for quotes on SF LBB blades.
- Hirata-san got a reduced quote for the LBB damper rings.
- Hirata-san received and cleaned suspension wires for the SR.
- Fabian worked on the SR mass budget.
- Fabian worked out the COM of the SR2 optic, and Mark used it to derive the proper prism positions.
- Enzo and Kozu-kun worked on control filter design and installation.
Plan for week of 11/27
- Fabian at commissioning workshop
- Hirata-san at Kamioka Tue-Fri to work with Mirapro on SRM LBB installation.
- All others (Mark, Enzo, Shoda-san, Kozu-kun) at Kamioka to start SR2 assembly.
- Mark from Mon lunchtime.
- Kozu-kun from Mon lunchtime through Wed.
- Mirror gluing.
- SR2 rack setup.
Plan for week of 12/4
- All at Kamioka
- IM assembly and pico test.
- Assembly frame alignment and optical table centering.
- OL setup.