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| ==== Report for week of 6/18 ==== * Mark checked the health of the suspensions after an earthquake on Monday morning. The BS watchdog tripped and there was a few µrad change in the pointing, but otherwise it was fine. SR3 and SR2 were also fine. * Mark, Enzo and Terrence finalized the trim mass on the BF to set the SF keystone height and BF pitch/roll. * They weighed the SF/... section. With no internal trim mass in the SF but with the flying saucer and rod, but with 2 Promec masses for rough balance, it was 255.4 kg, so allowing 1 kg for cables and fine trim mass, we would like a PI load capacity of 256.4 kg. * Enzo and Terrence cabled and tested the SF fishing rod, and reversed the connections on the SF LVDT actuation to bring it to standard polarity. * Mark and Enzo made many improvements to the Type B MEDM screens. * Enzo and Mark measured the BF and SF bounce frequencies (with the other keystone locked). * Enzo replaced a HPCD that seemed to have failed during the bounce test (but had just had a watchdog trip), and then replaced the replacement, which really did fail. It turns out we need to avoid applying more than about 25000 counts of GAS actuation. * Enzo offloaded the BF LVDT actuator with the BF FR to remove the need for a 10000 ct offset. * Hirata-san and Kozu-kun struggled to tune the top filter for SR3 - see klogs 5310, 5324, 5337, xxxx. At first the results were somewhat unrepeatable, with high frequency and low load capacity. This was improved by using a torque wrench (set to 50 N.m) to tighten the blade base clamp screws, retightening the blade tip screws (which had worked loose) and tightening the collar on the end of the shaft of the magic wand. Eventually we decided on a compression of 30 mm, which should give a frequency of around 0.5 Hz if we remove one Cu damper segment from the SF. Hirata-san applied the 30 mm compression but we skipped another round of testing with the dummy load and will go straight to hanging the SF/... section on the assembly frame. * We wrapped PI #1 (for SR2) and craned it from behind SR3 to behind SRM. We can now wrap PI #3 (for SR3) and crane it straight to the assembly frame. ==== Plan for week of 6/25 ==== * Mark, Enzo, Hirata-san, Terrence at Kamioka Mon-Fri. * Kozu-kun at Kamioka except Thu. * -- * Shutdown Type B controls (as far as possible) in preparation for risk of accidental power outage during electrical work on 6/26. * Prepare SF damper magnet ring and rods. * Install PI #3 in SR3 AF. * Suspend SF/... section. * Lots of cable routing and testing. * Move PI #1 (for SR2) over SRM tank to work area, install blades and tune. ==== Plan for week of 7/2 ==== * Mark, Hirata-san, Terrence at Kamioka Mon-Fri. * Enzo at Kamioka Mon-Wed. * Kozu-kun at Kamioka except Wed. * -- * Lock suspension. * Remove tank lid and raise LBB damper rings. * Crane suspension into tank. |
==== 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. [''As of Thursday afternoon, it had not yet been tested - UPDATE?''] * 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 SR2 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. [''Enzo was going to do f=1100 mm and maybe f=3500 mm on Friday morning 12/21 - UPDATE?''] * 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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| ==== Vacation Info ==== * Kozu-kun: 7/4 Tokyo. * Enzo: 7/5-6 NAOJ Party, Mitaka. * Terrence: 8/24-26 f2f, then returns to Hong Kong. * Enzo: 9/14 JPS, 9/15 through 10/18 vacation in Chile. |
==== 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 week of 12/24 ==== * Mark and Hirata-san on holidays, Enzo at Mitaka, Fabian. ==== 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: 12/31 - 1/4 * Enzo: 12/31 - 1/4. * 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
- 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. [As of Thursday afternoon, it had not yet been tested - UPDATE?]
- 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 SR2 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. [Enzo was going to do f=1100 mm and maybe f=3500 mm on Friday morning 12/21 - UPDATE?]
- 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 week of 12/24
- Mark and Hirata-san on holidays, Enzo at Mitaka, Fabian.
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: 12/31 - 1/4
- Enzo: 12/31 - 1/4.
- Mark and Enzo: KAGRA International Workshop in Perugia, 2/14-16.
- Terrence: back at Kamioka from 1/7.