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| At Kamioka (Mark, Fabian, Enzo, Hirata-san): | At Kamioka (Enzo): * Enzo (with help from Miyo-kun) fixed the broken actuation coil on PI LVDT #0. * Enzo worked on the final cabling plan for BS and SRx. * Enzo replaced the LVDT driver again to have one with no dead channels (and free up the partly non-working cards for servicing). |
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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. |
At Mitaka and Kashiwa (Mark, Hirata-san, Fabian, Enzo): * We glued magnets into their holders. * We did a walk-through of the gluing procedure at Mitaka and discovered that the secondary prisms were missing. * We took the mirror box and gluing tools to Kashiwa to do as much of the gluing as possible. * Hirose-san applied First Contact to the BS and he and Kieran moved it into the mirror box. * We practiced putting sapphire prisms on the BS but didn't apply glue. * We tried the magnet gluing jigs designed by Aso-san and found two major issues: the overall length was about 25 mm too long, and there was no adjustment to allow for the wedge. * We designed a simple modification to the jigs that hopefully would be trivial for the ATC to do: the jigs will be cut in half and the bottom section will be mounted with adhesive on an 11 mm rod that slides in the central hole of the top section. Thus the top half can be screwed into the existing recess, and the bottom half with the magnets and glue can be allowed to drop about 3 mm onto the face of the optic. Hirata-san worked with ATC to get this done and it should be ready today (Friday 7/7). * Hirata-san also got ATC to make some jigs to hold the old 5-mm prisms so that they can be ground down to 3 mm to replace the missing ones. Hirata-san will do the grinding himself today (Friday 7/7/). * We decided to continue the gluing work at Kamioka, so we brought the BS back to Mitaka and will ship it on to Kamioka next Tuesday. * Hirata-san did a version of the 3D CAD with the as-built BS Test Hang configuration. |
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| ==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for weeks of 7/10, 7/17 ==== Mark, Enzo mostly at Kamioka. * More TFs. * Receive BS at Kamioka, do gluing if possible. * Document LVDT driver rebuild and other changes. * Learn how Miyo-kun's pico driver software works and make fixes/improvements. * Design/install matrices, blend filters and damping filters. * Finish tidying rack and labeling cables. * Add temporary ballast to LBB and find total required. * Try rearranging arc weights to make room for magic wand. * Start on creating SR3 rack. * Preparation for BF rebuild. Fabian, Hirata-san at Mitaka. * Clean BS secondary prisms and modified gluing jigs (Hirata-san). * Ship gluing tools and BS to Kamioka. * Do new 3D CAD for final BS install (Hirata-san): * On-assembly-frame version. * In-tank version. * Design SR assembly frame (Fabian). * Do 2D Drawings and procurement of final IM/BF/SF ballast masses (Hirata-san). * Other purchasing and preparation (spare BS clamps, suspension wire, 8-mm rod receptacles) * Do mass budget for LBB - design ballast masses (Fabian) |
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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: 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 (Enzo):
- Enzo (with help from Miyo-kun) fixed the broken actuation coil on PI LVDT #0.
- Enzo worked on the final cabling plan for BS and SRx.
- Enzo replaced the LVDT driver again to have one with no dead channels (and free up the partly non-working cards for servicing).
At Mitaka and Kashiwa (Mark, Hirata-san, Fabian, Enzo):
- We glued magnets into their holders.
- We did a walk-through of the gluing procedure at Mitaka and discovered that the secondary prisms were missing.
- We took the mirror box and gluing tools to Kashiwa to do as much of the gluing as possible.
- Hirose-san applied First Contact to the BS and he and Kieran moved it into the mirror box.
- We practiced putting sapphire prisms on the BS but didn't apply glue.
- We tried the magnet gluing jigs designed by Aso-san and found two major issues: the overall length was about 25 mm too long, and there was no adjustment to allow for the wedge.
- We designed a simple modification to the jigs that hopefully would be trivial for the ATC to do: the jigs will be cut in half and the bottom section will be mounted with adhesive on an 11 mm rod that slides in the central hole of the top section. Thus the top half can be screwed into the existing recess, and the bottom half with the magnets and glue can be allowed to drop about 3 mm onto the face of the optic. Hirata-san worked with ATC to get this done and it should be ready today (Friday 7/7).
- Hirata-san also got ATC to make some jigs to hold the old 5-mm prisms so that they can be ground down to 3 mm to replace the missing ones. Hirata-san will do the grinding himself today (Friday 7/7/).
- We decided to continue the gluing work at Kamioka, so we brought the BS back to Mitaka and will ship it on to Kamioka next Tuesday.
- Hirata-san did a version of the 3D CAD with the as-built BS Test Hang configuration.
Plan for weeks of 7/10, 7/17
Mark, Enzo mostly at Kamioka.
- More TFs.
- Receive BS at Kamioka, do gluing if possible.
- Document LVDT driver rebuild and other changes.
- Learn how Miyo-kun's pico driver software works and make fixes/improvements.
- Design/install matrices, blend filters and damping filters.
- Finish tidying rack and labeling cables.
- Add temporary ballast to LBB and find total required.
- Try rearranging arc weights to make room for magic wand.
- Start on creating SR3 rack.
- Preparation for BF rebuild.
Fabian, Hirata-san at Mitaka.
- Clean BS secondary prisms and modified gluing jigs (Hirata-san).
- Ship gluing tools and BS to Kamioka.
- Do new 3D CAD for final BS install (Hirata-san):
- On-assembly-frame version.
- In-tank version.
- Design SR assembly frame (Fabian).
- Do 2D Drawings and procurement of final IM/BF/SF ballast masses (Hirata-san).
- Other purchasing and preparation (spare BS clamps, suspension wire, 8-mm rod receptacles)
- Do mass budget for LBB - design ballast masses (Fabian)
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