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| ==== Report for week of 9/24 ==== * Monday 9/24 was a holiday (Autumn Equinox). ===== SR2 ===== * We moved all the SR2 feedthrough and in-vacuum and in-air cables. * We tested all the OSEMs and most of the LVDTs. We still need to run power to the pico drivers, and test them and the steppers. * We unlocked and mostly realigned the suspension. The IM is sitting lower than before but can be brought up to nominal height with BF GAS offset, without any signs of anything touching. The IM also has a moderately large pitch (2.8 mrad according to the OSEMs, about 1 mrad according to the OL) and some roll, which we expect to be able to correct with some pico adjustment. The horizontal IM OSEMs are well-centered (so there is no yaw misalignment). ===== SRM ===== * We made another attempt to set the pitch of the SRM, but weren't satisfied with how close we were able to get (target 20 mm low, achieved 23 mm), so we didn't tighten the clamps or continue to setting the pitch of the RM. ==== Plan for week of 10/1 ==== * Mark, Hirata-san, Fabian, Panwei at Kamioka Mon-Fri. ===== SRM ===== * Set pitch of SRM and RM, tighten clamps, remove winch system. * Weigh IM/... section. * Build up SS to BF level. * Add BF. * Suspend IM and tweak height/balance. * Cable/test BF. * Install IRM. * Install/cable/test IM OSEMs. ==== Plan for week of 10/8 ==== * Monday 10/8 is Sports Day. * Enzo returns Tuesday 10/9. * Mark and Terrence (plus TBD) at Kamioka Mon-Fri. * Enzo, Hirata-san, Fabian and Panwei at Kamioka Tue-Fri. ===== SR2/SR3 ===== * Terrence to set up LEN half of SR3 OL and, time permitting, TILT and LEN for SR2. ===== SRM ===== * Continue installation. |
==== 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. |
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| ==== Vacation/Visitor Info ==== * Enzo: 9/15 through 10/8 vacation in Chile. * Terrence: 10/8-12, 10/29-11/2 at Kamioka. |
==== 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. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
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
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.