Scraps of text for incorporation in the VIS Meeting Minutes
Type B (Mark)
Past week report
At Kamioka (Mark, Fabian, Enzo, Perry, Hirata-san):
- We cleared space for the PR2 team to remove a bellows from their tank.
- We installed safety bars on the pillars near the assembly frame at about waist height for someone on the tall ladder. We reinforced the clamps with cable ties.
- We bridged a gap in the second floor on the -X side of the SF2 tank with spare floor panels.
- We removed the PI from the assembly frame.
- We encountered a problem with the PI-SF rod jamming in the SF. We finally got it out by clamping a pair of vice grips to the rod and hammering. We found that the receptacle part was the right size (7.0 mm) but had been deformed around the edge. Hirata-san used a knife and sandpaper to lean up the edge and then ultrasonically cleaned it.
- We removed the LLB blade units from the PI, removed the blades from the clamps and sent the blades away for more rework to fix the length problem. Fortunately the tab section at the tip is fairly long, so we can just add a second hole further from the end.
- We tested the SR fishing rod again, but it would only go up, not down. We found that reseting the driver fixed it, but we also moved the driver boxes into the cleanbooth to reduce the length of the motor cables. (To support the drivers, we had to run some long DC and LAN cables.)
- We adjusted the limit nut on the SF fishing rod to increase the range.
- We debugged an issue with the SF keystone sitting lower than previously and found we had accidentally left two eyebolts on top of the BF. We retrimmed the BF/... section to reset the keystone to nominal (65.5 mm) with the fishing rod at mid-range.
- We removed one segment of the Cu ring on the SF cap and reconfigured the other two to be symmetrical.
- Fabian designed a layout for the SF damper ring magnets that would work with the modified Cu ring, and placed the magnets with the template. The poles of the magnets were not on the expected faces so we had to stand the magnets up, with the 12x12 faces sideways and the 10x12 mm pole faces up/down. We will need to raise the magnet ring by 2 mm to allow for the extra height.
- Hirata-san made an adapter cable for the PI vertical LVDT to let it connect to a standard Type 1 cable.
- Enzo made a PI yaw/vertical stepper adapter cable and a trial geophone descrambler cable (one of three).
- We placed the geophones on the PI but discovered we didn't have some mounting brackets called out in the 3D CAD.
- Fabian added the remaining cable clamps to the PI.
- We found that part of the problem with the SF LVDT was that the actuation had not been enabled for SF or F0 in the real-time model. We fixed the model and are now able to drive the LVDT actuator and see input at the LVDT sensor. However there is apparently a lot of coupling directly from output to input (presumably from transformer action between the sensing and actuation coils), so we're investigating.
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.