Size: 3286
Comment:
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Size: 1900
Comment:
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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, Enzo, Yoshioka-kun, Kozu-kun): * We finished installing the RM OSEMs and installed the new Type5-2.2 and 5-2.4 OSEM cables. * We hung the RM and set its pitch. * We doubled-checked the BS and RM pitch, tightened the clamps and removed the winch system. * We installed the bottom section of the security structure to protect the RM/BS. * We lifted the IM/RM/BS section and weighed it. It was about 1.25 kg too heavy for the new BF, so we improvised a lighter set of ballast masses. * We installed the section of the security structure up to the BF ring, and the BF crossbars and jacks of the assembly frame. * We brought in the new BF. * We installed the BF-IRM rods and IRM top plate. * We reinstalled the IM flags and other items that had been taken off to use the winch system. * We hooked the BF-IM rod (with hex cable clamp). (We did not unlock the BF keystone.) * We cabled and tested the IM-PIT, IM-ROL and IM-YAW picos and the BF FR stepper (but not, yet, the BF LVDT). |
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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 8/14 ==== Site closure: Mon, Tue<<BR>> Vacation: Fabian (Mon-Fri)<<BR>> Kamioka: Mark (Wed-Fri), Enzo (Wed-Fri), Yoshioka-kun (Wed, Fri), Ohishi (Thu-Fri).<<BR>> * Remove LBB blade units from PI, then remove blades and send for remachining. * Remove LBB rings from chamber and send for recleaning. * Unlock BF, adjust ballast masses on IM/RM/BS to correct pitch/roll/vertical. * Test, calibrate BF LVDT. Mitaka: Hirata-san (Mon-Fri)<<BR>> * SR Stuff |
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==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 8/21 ==== Vacation: Fabian (Mon)<<BR>> Kamioka: Mark, Ohishi, Fabian (Tue-Fri), Enzo, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun. |
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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. |
Vacation Info: 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, Ohishi-san, Enzo, Yoshioka-kun, Kozu-kun):
- We finished installing the RM OSEMs and installed the new Type5-2.2 and 5-2.4 OSEM cables.
- We hung the RM and set its pitch.
- We doubled-checked the BS and RM pitch, tightened the clamps and removed the winch system.
- We installed the bottom section of the security structure to protect the RM/BS.
- We lifted the IM/RM/BS section and weighed it. It was about 1.25 kg too heavy for the new BF, so we improvised a lighter set of ballast masses.
- We installed the section of the security structure up to the BF ring, and the BF crossbars and jacks of the assembly frame.
- We brought in the new BF.
- We installed the BF-IRM rods and IRM top plate.
- We reinstalled the IM flags and other items that had been taken off to use the winch system.
- We hooked the BF-IM rod (with hex cable clamp). (We did not unlock the BF keystone.)
- We cabled and tested the IM-PIT, IM-ROL and IM-YAW picos and the BF FR stepper (but not, yet, the BF LVDT).
Plan for week of 8/14
Site closure: Mon, Tue
Vacation: Fabian (Mon-Fri)
Kamioka: Mark (Wed-Fri), Enzo (Wed-Fri), Yoshioka-kun (Wed, Fri), Ohishi (Thu-Fri).
- Remove LBB blade units from PI, then remove blades and send for remachining.
- Remove LBB rings from chamber and send for recleaning.
- Unlock BF, adjust ballast masses on IM/RM/BS to correct pitch/roll/vertical.
- Test, calibrate BF LVDT.
Mitaka: Hirata-san (Mon-Fri)
- SR Stuff
Plan for week of 8/21
Vacation: Fabian (Mon)
Kamioka: Mark, Ohishi, Fabian (Tue-Fri), Enzo, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun.
Vacation Info: Fabian: Fri 8/4 through Mon 8/21 Mark: TBD Mid-Oct