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| ==== Report for week of 12/17 ==== | ==== Report for the week of 3/18 ==== |
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| * 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. |
* Terrence notice that one of the IP LVDTs was not working. We traced it to an unplugged cable, plugged it back in and screwed it together to prevent a recurrence. * Simon helped us rebuild the damaged LEN OL QPD stage and Terrence reinstalled it. We removed a C-clamp that we had been using to immobilize the breadboard because it interfered with the QPD stage, and replaced it with a more elegant solution using a dog clamp underneath. * We noticed that the BS IP had fallen over in +L at some time shortly before Nakano-san aligned the optic on 3/18. Terrence tried to recenter it but it was unstable. We decided to remove the tank lid one more time and remove some arc weights. The IP frequency had been 39 mHz the last time it was measurable, and we increased it to a much-safer 80 mHz by removing 9 kg. We believe we were able to recover Nakano-san's alignment fairly closely. * Terrence then recalibrated and diagonalized both the TILT and LEN OL. * SR2 * Terrence recalibrated the OL. * SR3 * Mark pulled out unused cables leading into the SR3 cleanbooth. |
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| * 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 ==== * [[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)]] |
* Terrence set up the SRM Guardian. * Etc/All * Mark did an audit of the OL whitening/dewhitening system and fixed a bunch of problems: the SRM chassis was the wrong type, with no actual whitening card; SR2 and SRM needed whitening filters turned on; BS LEN needed the dewhitening turned on; SR2, SR3 and SRM needed dewhitening filters installed and turned on; SRM needed more gain. * Terrence weeded out a minor error from his OL diagonalization scheme and got L, T and Y independent at the 1% level for SR2 and SRM. He will do SR3 next. * Fabian measured the gain resistor values and other settings of the LVDT drivers, in case a card or chassis fails and we have to approximate the original state without the chance to recalibrate from scratch. * Fabian monitored the pumpdown. |
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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). |
==== Plan for week of 3/25 ==== * Mark, Fabian, Terrence at Kamioka Mon-Thu. * Assist with alignment. * Work on Type B paper. * Tidy up. * Throw out foil and other garbage. * Gather and clean tools. * Gather and organize unused parts and fasteners. * Return all unused cables to tent. * Tidy up cables in rear of SR2 rack. |
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| ==== Vacation/Etc Info ==== * Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16. * Terrence: back at Kamioka from 1/7. |
==== Vacation/Travel Info ==== * Enzo's final vacation till 3/29. * Terrence's last day for now, 3/29. * Mark compensation day for 3/21: 3/29. * Type B going-away party for Terrence/Enzo, 3/29 in Tokyo. * Terrence's next visit from 4/18. * Fabian's vacation 4/26 to 5/10. * Mark's final day ≈6/28 (TBD). |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for the week of 3/18
- BS
- Terrence notice that one of the IP LVDTs was not working. We traced it to an unplugged cable, plugged it back in and screwed it together to prevent a recurrence.
- Simon helped us rebuild the damaged LEN OL QPD stage and Terrence reinstalled it. We removed a C-clamp that we had been using to immobilize the breadboard because it interfered with the QPD stage, and replaced it with a more elegant solution using a dog clamp underneath.
- We noticed that the BS IP had fallen over in +L at some time shortly before Nakano-san aligned the optic on 3/18. Terrence tried to recenter it but it was unstable. We decided to remove the tank lid one more time and remove some arc weights. The IP frequency had been 39 mHz the last time it was measurable, and we increased it to a much-safer 80 mHz by removing 9 kg. We believe we were able to recover Nakano-san's alignment fairly closely.
- Terrence then recalibrated and diagonalized both the TILT and LEN OL.
- SR2
- Terrence recalibrated the OL.
- SR3
- Mark pulled out unused cables leading into the SR3 cleanbooth.
- SRM
- Terrence set up the SRM Guardian.
- Etc/All
- Mark did an audit of the OL whitening/dewhitening system and fixed a bunch of problems: the SRM chassis was the wrong type, with no actual whitening card; SR2 and SRM needed whitening filters turned on; BS LEN needed the dewhitening turned on; SR2, SR3 and SRM needed dewhitening filters installed and turned on; SRM needed more gain.
- Terrence weeded out a minor error from his OL diagonalization scheme and got L, T and Y independent at the 1% level for SR2 and SRM. He will do SR3 next.
- Fabian measured the gain resistor values and other settings of the LVDT drivers, in case a card or chassis fails and we have to approximate the original state without the chance to recalibrate from scratch.
- Fabian monitored the pumpdown.
Plan for week of 3/25
- Mark, Fabian, Terrence at Kamioka Mon-Thu.
- Assist with alignment.
- Work on Type B paper.
- Tidy up.
- Throw out foil and other garbage.
- Gather and clean tools.
- Gather and organize unused parts and fasteners.
- Return all unused cables to tent.
- Tidy up cables in rear of SR2 rack.
Vacation/Travel Info
- Enzo's final vacation till 3/29.
- Terrence's last day for now, 3/29.
- Mark compensation day for 3/21: 3/29.
- Type B going-away party for Terrence/Enzo, 3/29 in Tokyo.
- Terrence's next visit from 4/18.
- Fabian's vacation 4/26 to 5/10.
- Mark's final day ≈6/28 (TBD).