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| ==== Report for week of 7/30 ==== | ==== Report for week of 8/13 ==== KAGRA was closed Mon/Tue 8/13-14. |
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| * We undid the accidental misalignment of the SR3. We also switched off the BF GAS offset we had been using, let the IM rise until near zero on the BF LVDT, and adjusted the IM vertical OSEMs back to mid-range. * We closed control loops for the SR3 GAS filters. * Terrence set up the LED and TILT QPD for the final OL, and did a new calibration. |
* Enzo and team debugged an issue with height of the SR3 keystone coupling to yaw of the payload as measured by the OL. We suspect a ferromagnetic item on the SF damper, but we're not sure. ==== Report for week of 8/20 ==== ===== SR3 ===== * Hatoya-san and Enzo gathered date for a study of yaw mode Q damping time as a study of damper ring height. |
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| * We installed the SR2 SF damper magnet ring but found that the magnet pattern didn't match the Cu segments due to a different in the caps between SR3 and SR2. We raised the ring but left it suspended, clamped the template to the underside and rearranged the magnets. * We did a vertical height budget of the SR2. It turns out to have a very similar issue to the SR3: the chain is about 5 mm longer than the CAD, with about 3 mm of that between the SF and BF. We decided to do the same fix and operate with the F0 keystone 5 mm higher. We chose an total amount of ballast to give that keystone height and secured most of it to the SF, keeping a reserve for cables and the yaw stepper. * We routed most (all?) of the SF/... cabling up to the PI. |
* We continued with cabling work. * We configured the second pico driver and connected it. * We assembled the LBB damper rings in the tank, craned them to near the top and hooked them. While the tank was open we also set the jacks below the mushroom that will support the suspension to nominal height. |
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| ===== SRM ===== * We reserved and configured two pico drivers. * We checked the prism gluing and all the jigs came away successfully. * Fabian assembled the RM. * Hirata-san added ballast masses to the IM and we weighed it, as well as the RM and the optic in the mirror box. * We suspended the optic and RM. ==== Report for week of 8/27 ==== * We did an inventory of arc weights to see if we had enough for SRM and found that we had only enough for a basic allocation for all of type B (172 kg for BS and 103.2 kg per SR) and almost no spare for tuning. We did a quick study of the IP frequency as a function of the number of arc weights using SR3, to see how much more we might need. If SR3 is typical we would need about 27 kg extra per suspension. ===== SR3 ===== * After the IP study, we left the SR3 with 6 10-mm arc weights and measured its frequency (with the digital system instead of a stopwatch). ===== SR2 ===== * We finished routing the the in-vac |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 8/13
KAGRA was closed Mon/Tue 8/13-14.
SR3
- Enzo and team debugged an issue with height of the SR3 keystone coupling to yaw of the payload as measured by the OL. We suspect a ferromagnetic item on the SF damper, but we're not sure.
Report for week of 8/20
SR3
- Hatoya-san and Enzo gathered date for a study of yaw mode Q damping time as a study of damper ring height.
SR2
- We continued with cabling work.
- We configured the second pico driver and connected it.
- We assembled the LBB damper rings in the tank, craned them to near the top and hooked them. While the tank was open we also set the jacks below the mushroom that will support the suspension to nominal height.
SRM
- We reserved and configured two pico drivers.
- We checked the prism gluing and all the jigs came away successfully.
- Fabian assembled the RM.
- Hirata-san added ballast masses to the IM and we weighed it, as well as the RM and the optic in the mirror box.
- We suspended the optic and RM.
Report for week of 8/27
- We did an inventory of arc weights to see if we had enough for SRM and found that we had only enough for a basic allocation for all of type B (172 kg for BS and 103.2 kg per SR) and almost no spare for tuning. We did a quick study of the IP frequency as a function of the number of arc weights using SR3, to see how much more we might need. If SR3 is typical we would need about 27 kg extra per suspension.
SR3
- After the IP study, we left the SR3 with 6 10-mm arc weights and measured its frequency (with the digital system instead of a stopwatch).
SR2
- We finished routing the the in-vac
SRM
- We moved the SRM assembly frame into its final position, reset it to the initial configuration, double-checked the heights of the crossbars, and lowered the optical table by 3 mm (to give margin for the optic to rise during hanging, which we had kept forgetting to do). We cleaned it up with the airgun and wet-wipes. We installed the IM ring and IM.
- We assembled the SRM metal mass. Hirata-san made a jig from a plate with 4 screws which could safely hold the delicate front Sol-Black-coated ring upside down while the rest of the components were mounted on it.
- We moved the metal mass to the mirror box and added the prisms and magnet standoffs. We applied the EP30 on Friday morning, but probably won't be able to check the result until after Obon.
Plan for week of 8/13
- KAGRA closed Mon, Tue.
- Mark on vacation Mon-Thu, then Mitaka on Friday.
- Enzo, Fabian, Terrence, Panwei, Rikako at Kamioka Wed-Fri.
- Hirata-san on vacation all week.
- Fujii-kun to help part-time with crane work and/or the IP tuning.
- Diagonalization of new OL.
- TFs with new OL.
- Test of SF damper ring.
- Controls work.
- Tune SR3 IP.
Plan for week of 8/20
- Mark, Enzo, Hirata-san, Fabian, Kozu-kun, Terrence, Panwei at Kamioka Mon-Fri.
- Enzo, Hirata-san, Fabian, Kozu-kun, Terrence, Panwei at Kamioka Mon-Thu, then f2f.
- Kozu-kun works at Mozumi Mon.
SR3
- Hook LBB, add ballast mass.
- Tune IP.
SR2
- Adjust ballast/trim mass, with reserve for yaw stepper.
- Cable/test PI items (LVDTs, steppers, geophones).
- Set damper height.
- Add arc weights, adjust IP.
- Stage LBB damper rings in tank.
SRM
- Check gluing result - redo if necessary.
- Assemble RM.
- Add IM ballast masses (we forgot this before).
- Get parts from AOL and set up new pitch-setting OL.
- Hang metal mass.
- Hang RM.
To-Do Lists, Schedule
Vacation Info
- Mark: 8/13-16.
- Hirata-san: 8/13-17
- Terrence: 8/24-26 f2f, then returns to Hong Kong.
- Enzo: 9/14 JPS, 9/15 through 10/8 vacation in Chile.