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==== Past week report ==== At Kamioka (Mark, Fabian, Enzo, Hirata-san): |
==== Past two weeks report ==== Kamioka (Mark, Enzo, Kozu-kun): * Supported IA team. * Replaced LPCDs for IM OSEMs with HPCDs for increased pitch/yaw range. * Re-zeroed OL after significant change of beam position during IA. * Re-laid-out OL to improve focus of lens to LEN QPD. * Offloaded the pitch/yaw actuation at the IM OSEMs using the IM pitch/yaw picos. * Enzo worked on design of control loops using the OL. * Kozu-kun worked on diagonalizing the OL. |
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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. |
Mitaka (Fabian, Hirata-san): * Fabian did mechanical design: * F0 FR * Cable clamps for the SR IP base. * New SR recoil ballast masses. * LBB ballast. * Update of BS 3D CAD with the as-built ballast. * Hirata-san * made and updated inventory list for SR. * made order list and asked some quotes. * Ordered some parts. * Talked with mirapro about SRM optical bench. * Made some drawings for SR preparation. |
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==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 11/13 ==== |
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Week of 5/29, 6/6: * Cabling: * Route BF/... cabling up past SF to PI. * Route SF cabling up to PI. * Add Type 3 extensions to SF/... cables. * Move vacuum flanges to positions on assembly frame more convenient for next stage (accessible from second floor, one on each corner of frame). * Move in-air cabling to match flange positions. * Cable and test PI vertical LVDT. * Calibrate PI vertical LVDT. * Set yoke on PI vertical LVDT (if necessary). * Cable and test PI yaw stepper. * Cable and test PI vertical stepper. * Cable and test PI horizontal steppers. * Cable and test PI horizontal LVDTs. * Calibrate PI horizontal LVDTs. * Crane into tank. |
Enzo and Kozu-kun at Mitaka * Servos * Diagonalization of OL * TFs of BF * Documentation Mark and Fabian at Kamioka. * Mark attends commissioning workshop at U Toyama. * Support BF characterization work. * Prepare for mirror gluing. * Prepare for IM assembly. Hirata-san at Mitaka * SR procurement. * Get BS prism-gluing jigs reworked for use with PR/SR mirror box. ==== Plan for week of 11/20 ==== * Holiday on Thu 3/23 * Fabian at commissioning workshop * |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past two weeks report
Kamioka (Mark, Enzo, Kozu-kun):
- Supported IA team.
- Replaced LPCDs for IM OSEMs with HPCDs for increased pitch/yaw range.
- Re-zeroed OL after significant change of beam position during IA.
- Re-laid-out OL to improve focus of lens to LEN QPD.
- Offloaded the pitch/yaw actuation at the IM OSEMs using the IM pitch/yaw picos.
- Enzo worked on design of control loops using the OL.
- Kozu-kun worked on diagonalizing the OL.
Mitaka (Fabian, Hirata-san):
- Fabian did mechanical design:
- F0 FR
- Cable clamps for the SR IP base.
- New SR recoil ballast masses.
- LBB ballast.
- Update of BS 3D CAD with the as-built ballast.
- Hirata-san
- made and updated inventory list for SR.
- made order list and asked some quotes.
- Ordered some parts.
- Talked with mirapro about SRM optical bench.
- Made some drawings for SR preparation.
Plan for week of 11/13
Enzo and Kozu-kun at Mitaka
- Servos
- Diagonalization of OL
- TFs of BF
- Documentation
Mark and Fabian at Kamioka.
- Mark attends commissioning workshop at U Toyama.
- Support BF characterization work.
- Prepare for mirror gluing.
- Prepare for IM assembly.
Hirata-san at Mitaka
- SR procurement.
- Get BS prism-gluing jigs reworked for use with PR/SR mirror box.
Plan for week of 11/20
- Holiday on Thu 3/23
- Fabian at commissioning workshop