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| ==== Report for week of 11/12 ==== | ==== Report for week of 12/17 ==== |
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| * Kozu-kun noticed the BS OL was out of range, and Fabian and Fujii-kun investigated. It turns out that the temperature has risen by over 2°C, so all the GAS filters have sagged and several stages are touching. Miyoki-san and Furuta-san are looking at what can be done. * We ordered three more geophone cables in the standard (non-flipped pinout) to save time during the December vent, where we will replace at least two of the preamps to fix issues and take the opportunity to put in non-flipped ones. |
* Miyakawa-san worked on the BS real-time model and the gain/offset settings for the F0 LVDTINF block were lost, so we reentered them and did a new safe.snap file. |
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| * We cabled all the SF/... through to the rack and checked that all items worked. * We did the vertical height survey and found that as with SR2 and SR3, the chain is longer than the CAD, this time by ≈7 mm, and again mostly between the SF and BF. We decided on a keystone height of 11.5 mm (5 mm higher than CAD), which can be achieved with 1 kg more on the SF and 1 kg in reserve for a yaw stepper mechanism. We reset the height of the yoke to give near-zero LVDT output for the new nominal height, and corrected the sensing and actuation signs, but still need to do the calibration. * The final SRM small glass mirror became available, so we had Hirose-san ship it to us so we can install it while the suspension is still on the assembly frame. Hirata-san ordered shims to make up the new recommended thickness of 1.4 mm and a micrometer to check the combination, which should arrive on Monday 11/26. * Enzo took calibration data for the last batch of geophones, for SRM. We had to borrow cables from SR2 because one cable was missing and another was miswired. And it turned out that one of the SR2 cables was defective as well. But if we can find two possibly borrowed by Okutomi-san and rewire one, we should have enough for SR2 and SRM. The geophones appear to be healthy and we will seal them next week. * We raised the PI clear of the assembly frame and unlocked and centered the IP. We calibrated the IP LVDTs, and reversed connections to get positive LVDT output for positive yaw. We borrowed a HPCD from SR3-IM-V for the SRM IP but haven't checked the actuation yet. |
* We unlocked the IP adjusted the level with the jacks to center it. As hoped, this also improved the alignment of the chain insecurity structure and fixed a touching issue. * Hirata-san installed and cabled the new F0 yaw stepper. We had allowed plenty of reserve mass, so there was no problem getting back to nominal height of the keystone. * We found that the Nikhef method Fabian had used to tune the F0 LVDT driver gave an artificially narrow working range, so he retuned it with Enzo's method and recalibrated the LVDT. * Fabian did a vertical position survey with all the GAS filters at nominal and found the height of the RM above the SS bottom plate was about 2.5 mm lower than in the CAD. This is about what we expected from a chain 7 mm longer than CAD and and F0 keystone set to 5 mm higher than CAD. In future we can survey to either the optic or the security structure as convenient, and we are in the range where we should easily be able to match the correct beam height with the jacks under the PI. * We got two OL viewports for SRM from Akutsu-san, and will install them sometime in January, whenever we have a free moment. Akutsu-san pre-torqued the inner ring of screws around the glass, so we only need to torque the outer bolts. * SR3 * We also got a camera viewport for SR3 from Akutsu-san and will install it sometime in January. * Hirata-san installed and cabled the new F0 yaw stepper. |
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| * While we were grabbing geophone cables from SR2, we added extra arc weights to get the IP frequency below 0.1 Hz. * Akutsu-san showed us how to install the OL transmitter support pillar, receiver shelf and viewports. We believe we have the parts to finish setting up the SR2 OL. |
* Enzo calibrated the OL. He noted that with the standard f=2500 mm collimator, the angular range was only about 100 µrad in pitch and 150 µrad in yaw, which is rather less than Enomoto-kun's preferred range of more like 400 µrad, so we borrowed f=1100 mm and f=3500 mm collimators to characterize. * Hirata-san installed and cabled the new F0 yaw stepper. We did not have enough reserve mass for SR2, so to save 300 g we had Mesco make a new, lighter top plate, and Hirata-san ultrasonically cleaned it. We were then able to get the desired F0 keystone height with about 200 g to spare. * Etc * Enzo did a historical survey of the temperature as the various suspensions were being built and concluded that ideal operating temperature would be 25°C in the BS/SR2 area and 24°C for SR3/SRM. * Mark wrote a bash script to log all the GAS filter heights and LVDT actuation offsets, and an Excel spreadsheet to analyze the data to get an overview of the heights of the suspensions and the amount of height adjustment being used. He also reviewed old TF data to get near-DC values for the effect of GAS actuation on GAS height. This uncovered a few issues with calibration settings (such as for BS F0) having been lost because they hadn't been recorded in a safe.snap file, which we fixed. |
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| ==== Plan for week of 11/26 ==== * SRM * Clean tools and metal parts for final SRM glass mass. * Swap in final glass mass. * Adjust SF trim mass. * Check/adjust alignment of SS. * Calibrate IP LVDTs. * Add arc weights and geophones. * Improve centering/tuning of IP and SS alignment. * Disconnect cables at feedthroughs, lock suspension. * Crane into tank. * SR2 * Finish OL setup * TFs. * Control loops. |
==== Plan for week of 12/17 ==== * Final alignment of SRM payload, plus BF and SF GAS. * (Time permitting) unlocking/centering/tuning of IP. * Installation of Enomoto-kun's beam target on SRM (if available). * Installation/testing of F0 steppers on SR2, SR3, SRM, and (hopefully) final vertical height adjustment. * Installation of viewports on SRM. |
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| ==== Plan for week of 12/3 ==== * f2f Meeting at NAOJ - no Kamioka work. ==== Plan for week of 12/10 ==== * Prepare for vent of BS. * BS work - see [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]]. |
==== Plan for weeks of 12/24, 12/31 ==== * Most of team on holidays - no Kamioka work. |
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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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| ==== Vacation/Event Info ==== * Hirata-san at Mitaka, Fri 11/30 (medical check for solvent use). * Enzo at Mitaka, Fri 11/30 (Mitaka day). |
==== Vacation/Etc Info ==== * Mark: 12/24 - 1/4. * Hirata-san: 12/24 - 1/4. * Fabian: TBD but similar. * Enzo: TBD but similar. * Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 12/17
- BS
- Miyakawa-san worked on the BS real-time model and the gain/offset settings for the F0 LVDTINF block were lost, so we reentered them and did a new safe.snap file.
- SRM
- We unlocked the IP adjusted the level with the jacks to center it. As hoped, this also improved the alignment of the chain insecurity structure and fixed a touching issue.
- Hirata-san installed and cabled the new F0 yaw stepper. We had allowed plenty of reserve mass, so there was no problem getting back to nominal height of the keystone.
- We found that the Nikhef method Fabian had used to tune the F0 LVDT driver gave an artificially narrow working range, so he retuned it with Enzo's method and recalibrated the LVDT.
- Fabian did a vertical position survey with all the GAS filters at nominal and found the height of the RM above the SS bottom plate was about 2.5 mm lower than in the CAD. This is about what we expected from a chain 7 mm longer than CAD and and F0 keystone set to 5 mm higher than CAD. In future we can survey to either the optic or the security structure as convenient, and we are in the range where we should easily be able to match the correct beam height with the jacks under the PI.
- We got two OL viewports for SRM from Akutsu-san, and will install them sometime in January, whenever we have a free moment. Akutsu-san pre-torqued the inner ring of screws around the glass, so we only need to torque the outer bolts.
- SR3
- We also got a camera viewport for SR3 from Akutsu-san and will install it sometime in January.
- Hirata-san installed and cabled the new F0 yaw stepper.
- SR2
- Enzo calibrated the OL. He noted that with the standard f=2500 mm collimator, the angular range was only about 100 µrad in pitch and 150 µrad in yaw, which is rather less than Enomoto-kun's preferred range of more like 400 µrad, so we borrowed f=1100 mm and f=3500 mm collimators to characterize.
- Hirata-san installed and cabled the new F0 yaw stepper. We did not have enough reserve mass for SR2, so to save 300 g we had Mesco make a new, lighter top plate, and Hirata-san ultrasonically cleaned it. We were then able to get the desired F0 keystone height with about 200 g to spare.
- Etc
- Enzo did a historical survey of the temperature as the various suspensions were being built and concluded that ideal operating temperature would be 25°C in the BS/SR2 area and 24°C for SR3/SRM.
- Mark wrote a bash script to log all the GAS filter heights and LVDT actuation offsets, and an Excel spreadsheet to analyze the data to get an overview of the heights of the suspensions and the amount of height adjustment being used. He also reviewed old TF data to get near-DC values for the effect of GAS actuation on GAS height. This uncovered a few issues with calibration settings (such as for BS F0) having been lost because they hadn't been recorded in a safe.snap file, which we fixed.
To-Do Lists, Schedule
Plan for week of 12/17
- Final alignment of SRM payload, plus BF and SF GAS.
- (Time permitting) unlocking/centering/tuning of IP.
- Installation of Enomoto-kun's beam target on SRM (if available).
- Installation/testing of F0 steppers on SR2, SR3, SRM, and (hopefully) final vertical height adjustment.
- Installation of viewports on SRM.
Plan for weeks of 12/24, 12/31
- Most of team on holidays - no Kamioka work.
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: 12/24 - 1/4.
- Hirata-san: 12/24 - 1/4.
- Fabian: TBD but similar.
- Enzo: TBD but similar.
- Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.