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| * Type B Past Week Summary - week of 8/8 * Mark, Fabian and Hirata-san cleaned glue off the dummy BS, attached Akutsu-san's new SS mirror plates, reglued the flags and prisms, and removed the gluing hardware, so the dummy BS is ready for shipping. Tatsumi-san's refinements to the tooling (especially the new flag holders) worked very smoothly. We were more generous with the glue and much more careful with the alignment of the prisms to the barrel, both during rehearsal and the final gluing. * Mark wrote up the gluing procedure as a new document [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5505| E1605505]]. (The original plan was to do an addendum to Tatsumi-san's PR gluing procedure JGW-E1504248, but there was too much material.) * Hirata-san organized with Takahashi-san to get the BS payload masses shipped to Kamioka. They will go in an air-ride truck on Wed 8/17 together with a load of Type A stuff, and will arrive early on Thu 8/17. * Hirata-san shipped the collection of Type B fasteners to Kamioka, to arrive Mon 8/15. * Hirata-san measured another standard filter and cleaned various parts for people. * Hirata-san worked on the SR2 Inventor assembly. He spotted a problem with the orientation: given the position of the pistons in the SR2 tank (according to the assembly from Mirapro), mating the standard Type B SR chain and the chamber in the natural way puts the optic at 90° to what it needs to be. A similar problem was found in the Type B Test at Mitaka, and it was eventually worked around, but with some difficulty. Hirata-san will investigate the best way of making a correction. * Komori-kun, Kuwahara-kun and Akutsu-san calibrated an initial batch of 7 wide-mouthed OSEMs. * Fabian worked on the payload assembly procedure. * Type B Past Week Summary - week of 8/15 * Hirata-san shipped the fasteners to Kamioka, and they arrived Tuesday. * Hirata-san shipped a large load of Type A and Type B items, which Mark and Fabian received on Thursday 8/18. * Akutsu-san shipped the first 7 OSEMs. * Hirata-san and Ikenoue-san did a successful function test of the BS winches with the new clamp parts for the thicker wires. * Mark, Fabian and Zhao-kun did a major cleanup and reorganization of the BS clean booth at Kamioka, putting PR2 stuff in boxes, vacuuming and wiping, and making space. * Mark, Fabian and Zhao-kun set the crossbeams of the assembly frame to their correct positions and installed the EQ stop ring on top, ready to receive the IM. This is the first actual installation activity for Type B. * * Type B ongoing issues * Longer cables for BF->PI and SF->PI still not received, Takahashi-san to check status. * Longer term to-do list * Decide position of BS rack (in consultation with Miyakawa-san) - document in progress: [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5413| T1605413]] * Do Inventor assembly for SR2 in chamber and on assembly frame (Hirata) - ONGOING. * Write more of payload assembly procedure (Fabian) - ONGOING * Write more of 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]] (Mark) - ONGOING * Lower breadboard installation to be incorporated into the procedure document. * Work on BS simulation (Fabian) * 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. |
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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.