|
Size: 3286
Comment:
|
Size: 3666
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 7: | Line 7: |
| At Kamioka (Mark, Fabian, Enzo, Hirata-san): | At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Yoshioka-kun): * We moved all the in-air cables over to the tank. * We plugged all the in-air and in-vacuum cables into the feedthroughs and checked that we got signals from all the output channels (actuation not yet tested). We had to work around a snag with the new F-F gender changers that replace many Type 1 and Type 2 cables: like the vacuum feedthroughs, they flip pins 1 and 5. Electrically they could just be omitted, but the in-air cables don't plug directly into the feedthroughs very well, so we made up some non-flipping adapters similar to the anti-feedthrough adapters. * Hirata-san fixed a problem with one of the rods supporting the LBB Cu ring, where the head was not seating in the receptacle at the bottom. The head was slightly bent so he just reinstalled the rod upside-down to move the bent head to a less critical spot. (This also establishes that it's possible to install the rods later if we need to, although it's more convenient to bring them in with the suspension on the crane as we've been doing it.) * We suspended the LBB. Per a request from Akutsu-san, we set it as high as we easily could. We decided to try for 30 mm higher than in the CAD, for a height of 367 (instead of 397) mm for the beam line above the LBB. 40 mm would also be doable, but any more would need new rods, and more than ≈100 mm would cause the LBB to hit the bottom of the security structure. * We moved a lot of stuff out of the +X side of the cleanbooth to behind SRM, so that Mirapro could connect the section of beam duct between the BS tank and the X arm. They put the new section in position but have not connected it up yet. * Hirata-san worked with Mirapro to get the SR assembly frame assembled in the SR3 area. (Insertion of the LBB and installation of the top of the tank is planned for 10/18-20.) * We investigated a problem with the IM OSEM readings, which were far from mid-range. Although Fabian and Ohishi-san got the payload hanging nicely on Thu 9/21, sometime between then and when we plugged the OSEMs back in on 9/28, the BF and IRM apparently tipped considerably (with the +X corner high) so that the H2 and H3 OSEM flags are fouling on the bottom and top of their respective OSEMs. * We took the service ports off the BF tank at the BF level and trying correcting the tilt by moving the sliding masses around, but to no avail. Finally Hirata-san solved it by noticing that one of the BF-IRM rods was not seated properly at the top. Because it had been correct, and couldn't have fallen upwards, it must have gotten knocked during the LBB adjustment work. We locked the BF temporarily, lifted the corner of the IRM and jiggled the rod. It fell back into place and the alignment was much better. We backed out the sliding mass adjustments and it was back to normal. |
| Line 9: | Line 17: |
| * 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 week of 10/2 ==== Kamioka: Mark, Enzo (Tue-Fri), Ohishi-san, Kozu-kun. * Finish preparation for SR2 work. * Debug electronics, especially actuation. * Tune IP, do LVDT/stepper calibration. * Remove First Contact, try OL. Mitaka: Fabian, Hirata-san * Design ballast for LBB. * Design improved PI yaw adjustment. * SR procurement. |
| Line 35: | Line 28: |
| ==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 10/10 ==== Holiday Mon 10/9, Open Day prep Fri 10/13.<<BR>> * TFs, final preparation for alignment in week of 10/16. |
| Line 38: | Line 32: |
| 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. |
==== Plan for week of 10/16 ==== Kamioka: all but Mark * Work with alignment team. |
| Line 46: | Line 36: |
| ==== Vacation Info ==== Mark: 10/16-24 |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Past week report
At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Yoshioka-kun):
- We moved all the in-air cables over to the tank.
- We plugged all the in-air and in-vacuum cables into the feedthroughs and checked that we got signals from all the output channels (actuation not yet tested). We had to work around a snag with the new F-F gender changers that replace many Type 1 and Type 2 cables: like the vacuum feedthroughs, they flip pins 1 and 5. Electrically they could just be omitted, but the in-air cables don't plug directly into the feedthroughs very well, so we made up some non-flipping adapters similar to the anti-feedthrough adapters.
- Hirata-san fixed a problem with one of the rods supporting the LBB Cu ring, where the head was not seating in the receptacle at the bottom. The head was slightly bent so he just reinstalled the rod upside-down to move the bent head to a less critical spot. (This also establishes that it's possible to install the rods later if we need to, although it's more convenient to bring them in with the suspension on the crane as we've been doing it.)
- We suspended the LBB. Per a request from Akutsu-san, we set it as high as we easily could. We decided to try for 30 mm higher than in the CAD, for a height of 367 (instead of 397) mm for the beam line above the LBB. 40 mm would also be doable, but any more would need new rods, and more than ≈100 mm would cause the LBB to hit the bottom of the security structure.
- We moved a lot of stuff out of the +X side of the cleanbooth to behind SRM, so that Mirapro could connect the section of beam duct between the BS tank and the X arm. They put the new section in position but have not connected it up yet.
- Hirata-san worked with Mirapro to get the SR assembly frame assembled in the SR3 area. (Insertion of the LBB and installation of the top of the tank is planned for 10/18-20.)
- We investigated a problem with the IM OSEM readings, which were far from mid-range. Although Fabian and Ohishi-san got the payload hanging nicely on Thu 9/21, sometime between then and when we plugged the OSEMs back in on 9/28, the BF and IRM apparently tipped considerably (with the +X corner high) so that the H2 and H3 OSEM flags are fouling on the bottom and top of their respective OSEMs.
- We took the service ports off the BF tank at the BF level and trying correcting the tilt by moving the sliding masses around, but to no avail. Finally Hirata-san solved it by noticing that one of the BF-IRM rods was not seated properly at the top. Because it had been correct, and couldn't have fallen upwards, it must have gotten knocked during the LBB adjustment work. We locked the BF temporarily, lifted the corner of the IRM and jiggled the rod. It fell back into place and the alignment was much better. We backed out the sliding mass adjustments and it was back to normal.
Plan for week of 10/2
Kamioka: Mark, Enzo (Tue-Fri), Ohishi-san, Kozu-kun.
- Finish preparation for SR2 work.
- Debug electronics, especially actuation.
- Tune IP, do LVDT/stepper calibration.
- Remove First Contact, try OL.
Mitaka: Fabian, Hirata-san
- Design ballast for LBB.
- Design improved PI yaw adjustment.
- SR procurement.
Plan for week of 10/10
Holiday Mon 10/9, Open Day prep Fri 10/13.
- TFs, final preparation for alignment in week of 10/16.
Plan for week of 10/16
Kamioka: all but Mark
- Work with alignment team.
Vacation Info
Mark: 10/16-24