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==== Report for week of 11/19 ==== * BS * Fabian did some debugging on the BS and found that the calibration for the F0 LVDT was off due to an Excel error, and that the sag wasn't quite the 7 mm originally observed, but still enough to cause the suspension to touch down. Enzo tried applying LVDT actuation at the GAS filters and got it to lift off far enough to get sensible TFs, but the required BF offset was enough to put the IM OSEMs at the very edge of their usable range, so this is not a good long-term solution. We can probably raise the F0 keystone during the vent by removing mass and/or installing an auxiliary spring, which will then allow us to return the BF keystone to nominal height. * While working on the BS, Enzo noticed that one of the stepper drivers was not responding. It turned out to be water damaged from the rain issues earlier in the year. Enzo and Fujii-kun opened the rest of the BS chassises on the second floor but they seem to be OK. Tanaka-san had made a third driver chassis as a spare, so we reserved that and will install it in the week of 12/10. * SRM * The SRM-W optic arrived and we installed it in place of the SRM-M in the metal mass, taking care to use 1.4 mm shims as recommended by Hirose-san. The weight of the new assembly was within 1 g of the old and did not disturb the height of the payload. There was a very small change in pitch which we corrected with the IM picos. * We installed the shelf for the OL receiver. * We added the arc weights and geophones and went through several rounds of improving the centering of the IP and then realigning the security structure back to vertical. * We calibrated the F0 LVDT, and checked the F0 and IP actuation signs. * We adjusted the SF trim masses to set the SF pitch and roll, did an inventory of the trim mass and set the damper gap. * We did a final alignment of the whole chain and left the suspension ready for TFs during the f2f week. There is only a few hours of work left before we can install and we hope to do that on Monday 12/10. * SR2 * Enzo replaced the geophones and cables that had been borrowed for calibration and did several rounds of optimization of the IP frequency. He got as low as 46 mHz but with poor Q and so backed off a bit to 55 mHz and may back off a tiny bit more. * I derived updated IP matrices for the BS and SR, with more precise geometry data provided by Hirata-san, and published them as T1707205 and T1807663. * I created a CENTERING screen for the IP, with large panel meters for the LVDT signals and the derived L, T and Y signals. * Enzo confirmed that the fancy stepper control screen created by Shoda-san worked. * We installed a modified LPCD as IM-V for testing. * SR3 * We moved HPCDs from BS and SR2 to replace the ones that had been stolen from SR3, so as to create a working suspension with an OL for Kozu-kun. ==== To-Do Lists, Schedule ==== * [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]] * [[KAGRA/Subgroups/VIS/TypeB/ToDoSR]] * [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=7779|JGW-L1807779 Type B Schedule (SR)]] |
==== Report for the week of 3/4 ==== * On Monday, Mark helped Aso-san with PR3, and Monday, Tuesday and Wednesday, Fabian helped Fujii-kun with PRM. * Mark and Terrence attempted to offload some BS IM/IRM yaw adjustments that had been done by Enomoto-san last Friday. They rezeroed the OL and then opened the tank lid and did a compensating adjustment to the F0 yaw stepper, then undid the IM/IRM yaw with the pico. However this did not have the desired effect, probably because the buoyancy correction had not been cancelled when Enomoto-san was working and the BF keystone was very high, with the IM-V OSEMs way too far in and possibly touching. We did our best to back out all the adjustments but the roll TFs were still messy and there were signs that the IM was not free in yaw (the IM/IRM Y varied oppositely to IP Y, indicating that the IMR was free and the IM wasn't). We ended up deciding to have Mirapro remove the ducts on the ±X sides of the tank so we could go in and inspect. * Terrence tuned the SR3 LEN OL to be free of yaw cross-coupling. * Terrence and Enzo did a full set of filters and a Guardian for SR2 and SR3. * Terrence did health checks on SR2 and SR3. * Enzo measured mode Qs on SR2. ==== Plan for week of 3/11 ==== * Mark at Kamioka full week. * Enzo at Kamioka Mon, Tue, then JPS. * Hirata-san at Kamioka from Monday lunchtime through Friday. * Fix BS. * Final test of stepper remote enable system (someone in cleanroom checks the lights go on/off). * Continue monitoring SRM yaw drift. * More mode Q measurements. * Work on Type B paper. |
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==== Plan for week of 12/3 ==== * f2f Meeting at NAOJ - no Kamioka work. ==== Plan for week of 12/10 ==== * Crane SRM into tank. * Install new F0 yaw mechanisms on SRs. * Remove First Contact from SRM, unlock and realign. * Move SRM in-air cables over. |
==== Vacation/Travel Info ==== * Enzo at JPS then final vacation, 3/13-29 * Terrence's last day, 3/29. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for the week of 3/4
- On Monday, Mark helped Aso-san with PR3, and Monday, Tuesday and Wednesday, Fabian helped Fujii-kun with PRM.
- Mark and Terrence attempted to offload some BS IM/IRM yaw adjustments that had been done by Enomoto-san last Friday. They rezeroed the OL and then opened the tank lid and did a compensating adjustment to the F0 yaw stepper, then undid the IM/IRM yaw with the pico. However this did not have the desired effect, probably because the buoyancy correction had not been cancelled when Enomoto-san was working and the BF keystone was very high, with the IM-V OSEMs way too far in and possibly touching. We did our best to back out all the adjustments but the roll TFs were still messy and there were signs that the IM was not free in yaw (the IM/IRM Y varied oppositely to IP Y, indicating that the IMR was free and the IM wasn't). We ended up deciding to have Mirapro remove the ducts on the ±X sides of the tank so we could go in and inspect.
- Terrence tuned the SR3 LEN OL to be free of yaw cross-coupling.
- Terrence and Enzo did a full set of filters and a Guardian for SR2 and SR3.
- Terrence did health checks on SR2 and SR3.
- Enzo measured mode Qs on SR2.
Plan for week of 3/11
- Mark at Kamioka full week.
- Enzo at Kamioka Mon, Tue, then JPS.
- Hirata-san at Kamioka from Monday lunchtime through Friday.
- Fix BS.
- Final test of stepper remote enable system (someone in cleanroom checks the lights go on/off).
- Continue monitoring SRM yaw drift.
- More mode Q measurements.
- Work on Type B paper.
Vacation/Travel Info
- Enzo at JPS then final vacation, 3/13-29
- Terrence's last day, 3/29.