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| ==== Report for week of 10/1 ==== ===== SR2 ===== * We solved a mystery with the height of the BF keystone: it turns out that running the table KOACH filters in the tank warms it up (by about 1.5°C) and causes significant sag (700 µm). D'oh! * We ran power to the pico drivers. * We got the lower section of the SR2 fairly well aligned with just a bit of adjustment with the IM pitch and roll picos. * We helped Lucia double-check the geometry of the IP - the current matrix calculation assumes the FRs and the LVDT sensors and actuators are colocated, which is much closer to true than for the BS, but not quite right. * We gave up on doing anything more with SR2 for now because we're waiting on extra extension cables for the PI and Fujii-kun will want to borrow one of the geophones next week for a huddle test with new geophones. ===== SRM ===== * We set the pitch of the SRM and RM, tightened the clamps and removed the winch system. * We installed the BF crossbars of the assembly frame and the BF ring section of the security structure. * We lifted the IM/... section on the load gauge to find its weight. * We craned in the BF and removed the cap. * We installed the BF-IRM rods and the IRM top plate. * We installed the BF-IM maraging rod and flying saucer cable clamps. * We suspended the IM/... section and adjusted the trim masses for balance and total mass. It took quite a lot of adjustment in each of pitch, roll and vertical. The vertical was due to the fact that the weight of the IM/... section is very close to that of SR2/SR3 but the SRM BF is about 0.5 kg weaker. The roll was due to the fact that the default configuration of trim mass had no correction for the horizontal wedge on the optic. However the pitch is a bit of a mystery - nearly all of the removed mass had to come off the AR side. Fortunately we were able to correct for it entirely with masses we had in hand. * We routed the TM OSEM cables via the flying saucer up to the underside of the BF. * We got 2 power supplies from Shimode-san so we can fire up the SRM rack next week. He will also supply suitable cables to connect the power supplies to the DC power strip in the rack. * We received the replated yoke for the SRM top filter. ==== Plan for week of 10/8 ==== * Monday 10/8 is Sports Day. * Enzo returns Tuesday 10/9. * Mark and Terrence (plus TBD) at Kamioka Mon-Fri. * Enzo, Hirata-san, Fabian and Panwei at Kamioka Tue-Fri. ===== SR2/SR3 ===== * Terrence to set up LEN half of SR3 OL and, time permitting, TILT and LEN for SR2. ===== SRM ===== * Cable/test BF. * Install IRM. * Install/cable/test IM OSEMs. * Suspend/weigh/balance the BF/... section. |
==== 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. |
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| ==== Vacation/Visitor Info ==== * Enzo: 9/15 through 10/8 vacation in Chile. * Terrence: 10/8-12, 10/29-11/2 at Kamioka. |
==== 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. |
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.