Scraps of text for incorporation in the VIS Meeting Minutes
Type B (Mark)
Report for week of 12/17
- We opened the top of the BS tank after the vent.
- We inspected the BS F0 blades for cracks but still didn't find any.
- We removed the arc weights and geophones, and added new longer studs for the arc weights and new cables for the geophones. We then put back the original arc weights and new geophones.
- We measured the geometry of the various IP items to check the IP diagonalization matrices.
We installed the new double-sided F0 FR. We were not close to needing to add the optional CuBe spring. Unfortunately the FR had rather less friction but still didn't work. After checking a bunch of possibilities and comparing against SRM (also non-working) and SR2/SR3 (working), we suspect the carriage may be assembled upside down, with the metal plate below and the PEEK plate above. We will try changing it next week.
- We adjusted the F0 keystone trim mass and were able to get it to sit at CAD nominal height at nominal temperature (24.9°C) with mid-range FR and modest extra mass (413 g). Interestingly, we noticed that removing the arc weights and/or geophones reduced the load capacity by a few hundred grams.
- We measured the total range of the IP FRs in steps and set them to mid-range in preparation for tuning the IP frequency and (re-)centering the IP.
- We borrowed an LED from SR2 and set the pitch of the SRM optic.
- We found the SRM front end had crashed and could not be properly reset by cycling the power from the web interface. Yamamoto-san eventually got it working for us, although it didn't seem to take more than restarting the user and IOP models.
- We sealed and retested the new geophones originally intended for SRM, but decided to use them on BS instead.
- We installed the two OL viewports. We also tried to install the camera viewport but we couldn't get the Cu gasket to sit in the recess, so we gave up and will probably reallocate the camera viewport to SR3 for now (where it will go on a different type of flange which we've had success with. Saito-san says that we can get help with the SRM flange from Mirapro on 1/28.
- We opened the top of the tank briefly to inspect the configuration of the F0 FR, but didn't do any significant work.
- Hirose-san inspected inside the bottom part of the chamber and found some dust, so he recommended we wipe with Vectra-Alpha wipes (IPA-resistant type) and IPA. he gave us a powerful LED flashlight array and asked us to use it to look for dust in all the chambers.
- We gave Simon a list of items we still need for the SRM OL. He seemed to think that they should be in stock at Kamioka and will help us look for them next Tue 1/15.
- Mark and Enzo booked flights for the KAGRA International Workshop.
- Mark had to schedule a trip to Australia for the week of 1/21 to attend to family business.
To-Do Lists, Schedule
Plan for week of 1/7
- Make sure BS is floating, recenter OL to capture current yaw position.
- Vent BS.
- Inspect BS F0 blades for cracks.
Install new BS F0 FR, and (if necessary) auxiliary CuBe spring.
- Confirm geometry of LVDTs, geophones, FRs etc and update T1707205 if necessary.
- Replace geophone preamps and cables (to fix noise, offset, pinout flip issues).
- Add more mass to IP to get lower frequency.
- Adjust all GAS filters to near mid-range (using keystone mass for F0 as much as possible, and FR+LVDT for SF and BF).
- Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
- Terrence: back at Kamioka from 1/7.