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| At Kamioka (Mark, Fabian, Enzo, Hirata-san): | At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Yoshioka-kun): * We moved or covered stuff in the BS cleanbooth to prepare for the SR2 crane slot cutting and BS-> SR2 assembly frame move. * We put the service port covers back on at the BF level of the BS tank. * We used the PI jacks to center the bottom of the security structure around the RM. * We debugged a mechanical issue where the #2 IP LVDT had too narrow a gap between the moving and fixed parts, so that there was interference with only a very small clockwise yaw of the IP. We fixed it by moving the bottom baseplate (taking advantage of the fact that it was held by screws in oversize holes for this purpose). * We used the IP FRs to center the IP. * We set the gains on the IP LVDT driver. |
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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. |
==== Plan for week of 10/2 ==== Kamioka: Mark, Enzo (Tue-Fri), Ohishi-san, Kozu-kun. * Finish preparation for SR2 work. * Debug electronics, especially actuation. * Tune IP, do LVDT/stepper calibration. * Remove First Contact, try OL. Mitaka: Fabian, Hirata-san * Design ballast for LBB. * Design improved PI yaw adjustment. * SR procurement. |
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| ==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 10/10 ==== Holiday Mon 10/9, Open Day prep Fri 10/13.<<BR>> * TFs, final preparation for alignment in week of 10/16. |
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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 10/16 ==== Kamioka: all but Mark * Work with alignment team. |
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| ==== 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, Yoshioka-kun):
We moved or covered stuff in the BS cleanbooth to prepare for the SR2 crane slot cutting and BS-> SR2 assembly frame move.
- We put the service port covers back on at the BF level of the BS tank.
- We used the PI jacks to center the bottom of the security structure around the RM.
- We debugged a mechanical issue where the #2 IP LVDT had too narrow a gap between the moving and fixed parts, so that there was interference with only a very small clockwise yaw of the IP. We fixed it by moving the bottom baseplate (taking advantage of the fact that it was held by screws in oversize holes for this purpose).
- We used the IP FRs to center the IP.
- We set the gains on the IP LVDT driver.
Plan for week of 10/2
Kamioka: Mark, Enzo (Tue-Fri), Ohishi-san, Kozu-kun.
- Finish preparation for SR2 work.
- Debug electronics, especially actuation.
- Tune IP, do LVDT/stepper calibration.
- Remove First Contact, try OL.
Mitaka: Fabian, Hirata-san
- Design ballast for LBB.
- Design improved PI yaw adjustment.
- SR procurement.
Plan for week of 10/10
Holiday Mon 10/9, Open Day prep Fri 10/13.
- TFs, final preparation for alignment in week of 10/16.
Plan for week of 10/16
Kamioka: all but Mark
- Work with alignment team.
Vacation Info
Mark: 10/16-24