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| ==== Report for week of 10/1 ==== ===== SR2 ===== * We solved a mystery with the height of the BF keystone: it turns out that running the table KOACH filters in the tank warms it up (by about 1.5°C) and causes significant sag (700 µm). D'oh! * We ran power to the pico drivers. * We got the lower section of the SR2 fairly well aligned with just a bit of adjustment with the IM pitch and roll picos. * We helped Lucia double-check the geometry of the IP - the current matrix calculation assumes the FRs and the LVDT sensors and actuators are colocated, which is much closer to true than for the BS, but not quite right. * We gave up on doing anything more with SR2 for now because we're waiting on extra extension cables for the PI and Fujii-kun will want to borrow one of the geophones next week for a huddle test with new geophones. ===== SRM ===== * We set the pitch of the SRM and RM, tightened the clamps and removed the winch system. * We installed the BF crossbars of the assembly frame and the BF ring section of the security structure. * We lifted the IM/... section on the load gauge to find its weight. * We craned in the BF and removed the cap. * We installed the BF-IRM rods and the IRM top plate. * We installed the BF-IM maraging rod and flying saucer cable clamps. * We suspended the IM/... section and adjusted the trim masses for balance and total mass. It took quite a lot of adjustment in each of pitch, roll and vertical. The vertical was due to the fact that the weight of the IM/... section is very close to that of SR2/SR3 but the SRM BF is about 0.5 kg weaker. The roll was due to the fact that the default configuration of trim mass had no correction for the horizontal wedge on the optic. However the pitch is a bit of a mystery - nearly all of the removed mass had to come off the AR side. Fortunately we were able to correct for it entirely with masses we had in hand. * We routed the TM OSEM cables via the flying saucer up to the underside of the BF. * We got 2 power supplies from Shimode-san so we can fire up the SRM rack next week. He will also supply suitable cables to connect the power supplies to the DC power strip in the rack. * We received the replated yoke for the SRM top filter. ==== 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 ===== * Cable/test BF. * Install IRM. * Install/cable/test IM OSEMs. * Suspend/weigh/balance the BF/... section. |
==== 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.