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| ==== Report for week of 11/19 ==== | ==== Report for week of 12/17 ==== |
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| * 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. |
* We opened the top of the BS tank after the vent. * We inspected the BS F0 blades for cracks but still didn't find any. * We removed the arc weights and geophones, and added new longer studs for the arc weights and new cables for the geophones. We then put back the original arc weights and new geophones. * We measured the geometry of the various IP items to check the IP diagonalization matrices. * We installed the new double-sided F0 FR. We were not close to needing to add the optional !CuBe spring. Unfortunately the FR had rather less friction but still didn't work. After checking a bunch of possibilities and comparing against SRM (also non-working) and SR2/SR3 (working), we suspect the carriage may be assembled upside down, with the metal plate below and the PEEK plate above. We will try changing it next week. * We adjusted the F0 keystone trim mass and were able to get it to sit at CAD nominal height at nominal temperature (24.9°C) with mid-range FR and modest extra mass (413 g). Interestingly, we noticed that removing the arc weights and/or geophones reduced the load capacity by a few hundred grams. * We measured the total range of the IP FRs in steps and set them to mid-range in preparation for tuning the IP frequency and (re-)centering the IP. |
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| * 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. |
* We borrowed an LED from SR2 and set the pitch of the SRM optic. * We found the SRM front end had crashed and could not be properly reset by cycling the power from the web interface. Yamamoto-san eventually got it working for us, although it didn't seem to take more than restarting the user and IOP models. * We sealed and retested the new geophones originally intended for SRM, but decided to use them on BS instead. * We installed the two OL viewports. We also tried to install the camera viewport but we couldn't get the Cu gasket to sit in the recess, so we gave up and will probably reallocate the camera viewport to SR3 for now (where it will go on a different type of flange which we've had success with. Saito-san says that we can get help with the SRM flange from Mirapro on 1/28. |
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| * 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. | * We opened the top of the tank briefly to inspect the configuration of the F0 FR, but didn't do any significant work. * Hirose-san inspected inside the bottom part of the chamber and found some dust, so he recommended we wipe with Vectra-Alpha wipes (IPA-resistant type) and IPA. he gave us a powerful LED flashlight array and asked us to use it to look for dust in all the chambers. * Etc * We gave Simon a list of items we still need for the SRM OL. He seemed to think that they should be in stock at Kamioka and will help us look for them next Tue 1/15. * Mark and Enzo booked flights for the KAGRA International Workshop. * Mark had to schedule a trip to Australia for the week of 1/21 to attend to family business. |
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| ==== Plan for week of 1/7 ==== * Make sure BS is floating, recenter OL to capture current yaw position. * Vent BS. * Inspect BS F0 blades for cracks. * Install new BS F0 FR, and (if necessary) auxiliary CuBe spring. * Confirm geometry of LVDTs, geophones, FRs etc and update T1707205 if necessary. * Replace geophone preamps and cables (to fix noise, offset, pinout flip issues). * Add more mass to IP to get lower frequency. * Adjust all GAS filters to near mid-range (using keystone mass for F0 as much as possible, and FR+LVDT for SF and BF). |
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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/Etc Info ==== * Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16. * Terrence: back at Kamioka from 1/7. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 12/17
- BS
- We opened the top of the BS tank after the vent.
- We inspected the BS F0 blades for cracks but still didn't find any.
- We removed the arc weights and geophones, and added new longer studs for the arc weights and new cables for the geophones. We then put back the original arc weights and new geophones.
- We measured the geometry of the various IP items to check the IP diagonalization matrices.
We installed the new double-sided F0 FR. We were not close to needing to add the optional CuBe spring. Unfortunately the FR had rather less friction but still didn't work. After checking a bunch of possibilities and comparing against SRM (also non-working) and SR2/SR3 (working), we suspect the carriage may be assembled upside down, with the metal plate below and the PEEK plate above. We will try changing it next week.
- We adjusted the F0 keystone trim mass and were able to get it to sit at CAD nominal height at nominal temperature (24.9°C) with mid-range FR and modest extra mass (413 g). Interestingly, we noticed that removing the arc weights and/or geophones reduced the load capacity by a few hundred grams.
- We measured the total range of the IP FRs in steps and set them to mid-range in preparation for tuning the IP frequency and (re-)centering the IP.
- SRM
- We borrowed an LED from SR2 and set the pitch of the SRM optic.
- We found the SRM front end had crashed and could not be properly reset by cycling the power from the web interface. Yamamoto-san eventually got it working for us, although it didn't seem to take more than restarting the user and IOP models.
- We sealed and retested the new geophones originally intended for SRM, but decided to use them on BS instead.
- We installed the two OL viewports. We also tried to install the camera viewport but we couldn't get the Cu gasket to sit in the recess, so we gave up and will probably reallocate the camera viewport to SR3 for now (where it will go on a different type of flange which we've had success with. Saito-san says that we can get help with the SRM flange from Mirapro on 1/28.
- SR3
- We opened the top of the tank briefly to inspect the configuration of the F0 FR, but didn't do any significant work.
- Hirose-san inspected inside the bottom part of the chamber and found some dust, so he recommended we wipe with Vectra-Alpha wipes (IPA-resistant type) and IPA. he gave us a powerful LED flashlight array and asked us to use it to look for dust in all the chambers.
- Etc
- We gave Simon a list of items we still need for the SRM OL. He seemed to think that they should be in stock at Kamioka and will help us look for them next Tue 1/15.
- Mark and Enzo booked flights for the KAGRA International Workshop.
- Mark had to schedule a trip to Australia for the week of 1/21 to attend to family business.
To-Do Lists, Schedule
Plan for week of 1/7
- Make sure BS is floating, recenter OL to capture current yaw position.
- Vent BS.
- Inspect BS F0 blades for cracks.
Install new BS F0 FR, and (if necessary) auxiliary CuBe spring.
- Confirm geometry of LVDTs, geophones, FRs etc and update T1707205 if necessary.
- Replace geophone preamps and cables (to fix noise, offset, pinout flip issues).
- Add more mass to IP to get lower frequency.
- Adjust all GAS filters to near mid-range (using keystone mass for F0 as much as possible, and FR+LVDT for SF and BF).
Vacation/Etc Info
- Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
- Terrence: back at Kamioka from 1/7.