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* Type B Past Week Summary * Fabian, Mark, Yokogawa-kun and Kuwahara-kun did BS installation at Kamioka: * Hung RM. * Did permanent routing of RM OSEM cables to IM. * Did temporary routing of RM OSEM in-vacuum cables to flange (4 channels). * Did semi-permanent routing of all OSEM external cables to satellite amps (10 channels) * Did temporary routing of RM OSEMs to PR2 rack (4 channels). * Took data with geophones connected but immobilized and then stored geophones in boxes. * Tested signals from first satellite amp getting to digital system. * Weighed mirror box. * Did fit check of flag holders for stub flags. Very minor adjustments will be needed. * Covered everything in preparation for modifications to clean booth roof (9/20-21). * Hirata-san: * Finished 3D CAD of SR2 and SR3 in tanks, with optical layout included. * Started 3D CAD for SRM. * Checked flag design. * Assembled a bottom filter (ongoing). * Cleaned maraging rods. * Type B ongoing issues * Longer term to-do list * Do Inventor assembly for SRx in chamber and on assembly frame (Hirata) - SR2/SR3 DONE, SRM ongoing. * Part "disk security" top has to be modified - screw positions do not match. * 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.