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| * Type B Past Week Summary * Mark and Fabian went to Kashiwa to clean up glue residue on the dummy BS and do a fit/function test of Tatsumi-san's modified tooling. * Most of the remaining glue came off with soaking in acetone, but there is still some in the machining grooves in the Al surface. Probably more work is required. * A set of cleanroom shoes borrowed from the ATC disintegrated when worn (the plastic had perished from age), which put small pieces of foam all over the floor in Hirose-san's cleanroom and required a lot of clean-up with a sticky roller! Cleanroom suits and shoes for use by Type B team at Mitaka/Kashiwa have been ordered, but will take another week to arrive. * The flag holding parts are now much easier to place and remove, much reducing the risk of breaking flags after gluing. * The sapphire and metal prisms from both the first BS gluing and the PR3 hanging test mirror were brought back to Mitaka for ultrasonic cleaning to remove glue, so they can be reused. * We arranged with Hirose-san to collect the dummy BS and mirror box next Thursday 8/4. (This is conditional on the new clean suits arriving.) Further work will be done at Mitaka. * Hirata-san arranged to borrow the NAOJ Hi-Ace van for the trip. * Hirata-san found the SR versions of the screws for immobilizing the IM and IRM. These fit much better than the BS ones (despite being the same design) and will be used for the BS. * Fabian updated the [[attachment:Geophone_Kamioka.png|geophone noise plot]] with a more accurate calibration and also plotted the [[attachment:Geophone_Kamioka_noise_ratio.png|S/N over readout noise]]. * Fabian identified 210 g of the 600 g deficiency in the IM mass as due to SS parts on the outside. However identifying the rest would require time-consuming disassembly of the IM, and it's not worth it because whatever the cause, the fix is to design and add more trim mass. * Hirata-san measured another filter, and worked on buying various small items. * Mark moved most of the contents of a bunch of older Dropbox and OneDrive shared folders into a new /Subsystems/VIS/TypeB folder on the KAGRA Dropbox. * Mark worked on a list of considerations for locating the BS rack, in preparation for discussions with Miyakawa-san et al. * Type B ongoing issues * OSEMs * Akutsu-san is working to get wide-mouth OSEMs ([[http://klog.icrr.u-tokyo.ac.jp/osl/?r=1853|2 assembled]]; first 4 expected to be assembled and washed by 8/8) * Longer cables for BF->PI and SF->PI. * Connectors RECEIVED, cables being made. * SR machining test NEARLY DONE. The part looks good and will be used but the ones for SR3 and SRM will be made from scratch. * Lower breadboard stuff * Installation to be incorporated into the procedure document. Mark/Takahashi to discuss. * Breadboard springs - RECEIVED. * Documents * BS Assembly Procedure [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4235| E1504235]], [[https://onedrive.live.com/redir?resid=D5CCFA70A378E0D0!195&authkey=!AM_usynuo9QI57g&ithint=folder,webloc|E1504235 draft]] * To-do list during Mark's vacation * Weigh IM/RM/IRM (Fabian, Hirata) - DONE but anomalies found. * Pack/ship IM/RM/IRM to Kamioka (Hirata/Fabian) - from 8/1. * Analyze geophone data (Fabian/Shoda) - data taken by Shoda-san; Fabian to find calibration factors. * Remove glue from dummy BS face (Fabian) - MOSTLY DONE. * Reglue flags and prisms (Tatsumi, Fabian) - from Friday 8/5. * Clean wire for BS and RM (Hirata) - DONE * Get new winch parts for new wire diameters - design received from Ikenoue-san * Do fit/function test of winches (Fabian/Hirata) * Ship winches to Kamioka (Hirata/Fabian) * Work on BS simulation (Fabian) * Do Inventor assembly for SR2 in chamber and on assembly frame (Hirata) - ONGOING. * Write more of payload assembly procedure (Fabian) * Write more of main assembly procedure (Mark) * Longer term to-do list * Do BS Simulink model (Mark, Kokeyama) * Do 2D drawings of SR2 parts (Hirata) * Redesign SRx IM wire clamps for larger prisms, remachined RMs. * Order SRM/PRM parts (Hirata/Shoda) * Order SRx fasteners (Hirata) |
=== Type B (Mark) === ==== Past week report ==== At Kamioka (Mark, Fabian, Enzo, Hirata-san): * 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 coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. 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. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past week report
At Kamioka (Mark, Fabian, Enzo, Hirata-san):
- 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 coming weeks
For more detail, see KAGRA/Subgroups/VIS/TypeB/ToDo.
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.