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| ==== Report for week of 10/22 ==== ===== SRM ===== * We borrowed the TM HPCDs from SR2 and SR3 so that SRM had HPCDs for IM-H, IM-V and GAS. * Fabian adjusted the last two OSEMs (IM-H2 and H3). * We closed the BF and weighed the BF/... section. * Fabian and Hirata-san routed all the BF/... cables via the BF cap (except for the four TM OSEM cables, where we're still waiting for extensions). * We built up the assembly frame and security structure to the SF level and craned in the SF. * We installed the SF-BF rod and flying saucer, and suspended the BF/... section. We will need about 600 g on the BF cap for balance and SF keystone height, which is as expected and not a problem. * Hirata-san collected a suitable CuBe spring and bracket parts from Type A. He ultrasonically cleaned the bracket and then installed the bracket and spring on the F0. The frequency increased from 0.5 Hz to 0.625 Hz, so he did another round of compression, from 30 mm to 31.3 mm. * Enzo soldered some short and/or broken cables to make longer cables that we need urgently. He got in touch with Yamamoto-san to arrange bringing them to Toyama University and ultrasonically cleaning them. * We pulled out cables running to the OMMT area that were used for the old OSEM/geophone testing setup and started a new geophone testing setup in the SR3 area using the optical table from the SR2 assembly frame. * Hirose-san reported results from his astigmatism test on the second SRM small optic and metal mass. With the tight shims (1.0 mm thickness, as used for the installed SRM) there was substantial astigmatism, but with the next looser available size (1.5 mm) there was no astigmatism but the optic is held very poorly and rattles. Hirose-san is ordering some intermediate thicknesses and will make a recommendation. However he will almost certainly suggest that we change the shims on the hanging SRM, so we need to think about whether that is feasible. ===== SR2 ===== * Akutsu-san collected the parts we will need for the SR2 OL so that Terrence can install it next week. * Hirata-san supervised the disassembly of the assembly frame. The pieces are now in the IMMT area, although we may need to move them again because they're a bit in the way. ==== Plan for week of 10/29 ==== * Mark, Enzo, Hirata-san, Fabian and Terrence at Kamioka Mon-Fri. ===== SR2 ===== * Set up OL. * Possibly do a measurement of how much torque is required on the F0 keystone to move the system in yaw. (This will help Sato-san choose a suitable stepper driver for the new design.) * Possibly add more arc weights, to get below 0.1 Hz. ===== SRM ===== * Continue assembly. |
==== 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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| ==== Plan for week of 10/29 ==== * Mark, Enzo, Hirata-san and Fabian at Kamioka Mon-Fri (except Hirata-san to take compensation day Friday or Monday (TBD)). ===== SRM ===== * Continue assembly. |
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| ==== Vacation/Visitor Info ==== * Terrence: 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.