Scraps of text for incorporation in the VIS Meeting Minutes
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.