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Size: 3286
Comment:
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Size: 2688
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): | At Kamioka (Mark, Enzo, Hirata-san, Yoshioka-kun): * We disassembled the suspension. * We removed all the cables and bagged and labelled them for reuse. * The PI is parked on the pallet. * The SF was initially parked between the frame and tank and then manhandled to one side. The same procedure was used for the SF ring. * The BF was parked between the assembly frame and tank. The BF ring was stored in the top of the structure. * We removed various useful and no-longer-needed items from the BF, including the lower rod receptacle, thrust bearing, fishing rod and temporary ballast masses. * We cut the wires and removed the RM and dummy BS on the RM trolley. * The wire clamps were moderately deeply scarred and could probably be reused, but we plan to use the new set, which will be available on Tuesday of next week. * We discovered that the problem with the old BF was due to the fishing rod, which had not had a pair of lock nuts and had been damaged by being drive too high, so that the springs hit the underside of the cap and were bent at the base. We will install lock nuts and set them to the correct height for the final installation. * The gluing of the BS primary prisms and magnets went well, but we had to reglue the secondary prisms because they stuck to the jigs and were pulled off when the jigs were retracted. The second try went well and the BS is ready for use. * Fabian and Hirata-san characterized 7 new BS BF blades. There was one outlier but the rest were in a tight group. * Hirata-san used 3 of the blades to build a new BF. * Miyo-kun and others from the Type Bp team did a lot of tidying up of the BS rack for us, and removed a lot of in-air cables running through the cleanbooth. When he returns, on 8/8, Enzo will coordinate relaying the cables in the cable trays (which were not installed when the initial cabling was done). |
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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. |
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| ==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 7/24 ==== Full team at Kamioka from Mon-Fri, except Hirata-san (Tue-Fri) and Enzo (vacation). * Check results of gluing. * Finish disassembly. * Finish BF rebuild. * Remove LBB rings. * Recheck alignment of assembly frame and centering of optical table. * Install IM, suspend BS and RM. |
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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 7/31 ==== Full team at Kamioka from Mon-Fri, except Fabian (Mon-Thu) and Enzo (vacation). * Weigh/trim BS/RM/IM. * Bring in rebuilt BF. |
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| Vacation Info: Hirata-san: Thu 7/20 through Mon 7/24 Enzo: Sat 7/22 through Sun 8/6 Fabian: Fri 8/4 through Mon 8/21 Mark: TBD Mid-Oct |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past week report
At Kamioka (Mark, Enzo, Hirata-san, Yoshioka-kun):
- We disassembled the suspension.
- We removed all the cables and bagged and labelled them for reuse.
- The PI is parked on the pallet.
- The SF was initially parked between the frame and tank and then manhandled to one side. The same procedure was used for the SF ring.
- The BF was parked between the assembly frame and tank. The BF ring was stored in the top of the structure.
- We removed various useful and no-longer-needed items from the BF, including the lower rod receptacle, thrust bearing, fishing rod and temporary ballast masses.
- We cut the wires and removed the RM and dummy BS on the RM trolley.
- The wire clamps were moderately deeply scarred and could probably be reused, but we plan to use the new set, which will be available on Tuesday of next week.
- We discovered that the problem with the old BF was due to the fishing rod, which had not had a pair of lock nuts and had been damaged by being drive too high, so that the springs hit the underside of the cap and were bent at the base. We will install lock nuts and set them to the correct height for the final installation.
- The gluing of the BS primary prisms and magnets went well, but we had to reglue the secondary prisms because they stuck to the jigs and were pulled off when the jigs were retracted. The second try went well and the BS is ready for use.
- Fabian and Hirata-san characterized 7 new BS BF blades. There was one outlier but the rest were in a tight group.
- Hirata-san used 3 of the blades to build a new BF.
- Miyo-kun and others from the Type Bp team did a lot of tidying up of the BS rack for us, and removed a lot of in-air cables running through the cleanbooth. When he returns, on 8/8, Enzo will coordinate relaying the cables in the cable trays (which were not installed when the initial cabling was done).
Plan for week of 7/24
Full team at Kamioka from Mon-Fri, except Hirata-san (Tue-Fri) and Enzo (vacation).
- Check results of gluing.
- Finish disassembly.
- Finish BF rebuild.
- Remove LBB rings.
- Recheck alignment of assembly frame and centering of optical table.
- Install IM, suspend BS and RM.
Plan for week of 7/31
Full team at Kamioka from Mon-Fri, except Fabian (Mon-Thu) and Enzo (vacation).
- Weigh/trim BS/RM/IM.
- Bring in rebuilt BF.
Vacation Info: Hirata-san: Thu 7/20 through Mon 7/24 Enzo: Sat 7/22 through Sun 8/6 Fabian: Fri 8/4 through Mon 8/21 Mark: TBD Mid-Oct