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==== Report for week of 8/13 ====
 * KAGRA was closed Mon/Tue 8/13-14 due to O-Bon.
 * Enzo and team debugged an issue with height of the SR3 keystone coupling to yaw of the payload as measured by the OL. We suspect a ferromagnetic item on the SF damper, but we're not sure.

==== Report for week of 8/20 ====
===== SR3 =====
 * Hatoya-san and Enzo gathered date for a study of yaw mode Q damping time as a study of damper ring height.
===== SR2 =====
 * We continued with cabling work.
 * We configured the second pico driver and connected it.
 * We assembled the LBB damper rings in the tank, craned them to near the top and hooked them. While the tank was open we also set the jacks below the mushroom that will support the suspension to nominal height.

===== SRM =====
 * We reserved and configured two pico drivers.
 * We checked the prism gluing and all the jigs came away successfully.
 * Fabian assembled the RM.
 * Hirata-san added ballast masses to the IM and we weighed it, as well as the RM and the optic in the mirror box.
 * We suspended the optic and RM.

==== Report for week of 8/27 ====
===== SR3 =====
 * We did an inventory of arc weights to see if we had enough for SRM and found that we had only enough for a basic allocation for all of type B (172 kg for BS and 103.2 kg per SR) with almost no spare for tuning.
 * Using SR3, we did a quick study of the IP frequency as a function of the number of arc weights, to see how much more we might need. 3 pairs of small arc weights (10 mm thick, 4.53 kg each) brought the frequency below 0.1 Hz, 4 pairs made it unstable. If SR3 is typical we would need about 27 kg extra per suspension.
 * After the IP study, we left three pairs of 10 mm arc weights installed on the IP for more investigation with the digital system (instead of a stopwatch). ''RESULTS.''

===== SR2 =====
 * We finished routing the in-vacuum cables, and connected everything through to the rack for final testing.
 * We brought a basic 103.2 kg set of arc weights (3 large (38 mm) and 6 medium (19 mm)) into the SR2 cleanbooth.

===== SRM =====
 * Panwei calibrated 6 OSEMs to be used on the IM.
 * We brought in all the remaining arc weights from the pallet into the SRM cleanbooth, and Hirata-san cleaned up 1 large arc weight and 3 mediums left over from the BS that complete a basic set of 103.2 kg, plus about 5 kg spare. (However 27 kg of these are on loan to SR3.)
 * We assembled and installed the bottom section of the security structure under the optic and RM.
 * We set up a new OL for setting the pitch. We found the reflection off the AR surface was much weaker than for SR2 and SR3, but fortunately the HR surface is almost flat (ROC≈300 m) so we were able to use the HR reflection instead.
 * ''We set the pitch of the SRM and RM and tightened the wire clamps.''

==== Plan for week of 9/3 ====
 * Mark, Enzo, Hirata-san, Fabian, Kozu-kun, Panwei at Kamioka Mon-Fri.
 * (Mark possible trip to LIGO Hanford - TBD.)
===== SR2 =====
 * Crane in SR2.
 * Move SR2 in-air cables.
 * Remove First Contact. ''DO WE NEED TO GET THE DUCT MOVED FIRST???''
 * Unlock and realign payload.

===== SRM =====
 *
===== Etc =====
 * Prepare for scheduled power outage on 9/10.

==== Plan for week of 9/10 ====
 * Monday 9/10 is scheduled power outage.
 * Mark, Hirata-san, Fabian, Kozu-kun, Panwei at Kamioka Tue-Fri.
 * Enzo at Kamioka Tue-Thu, then JPS Meeting Fri, then vacation.
 * (Mark possible trip to LIGO Hanford - TBD.)
 * Recover from power outage.

==== Plan for week of 9/17 ====
 * Monday 9/17 is holiday (Respect for the Aged Day).
 * Enzo on vacation.
 * Mark, Hirata-san, Fabian, Kozu-kun, Panwei at Kamioka Tue-Fri.

==== Plan for week of 9/24 ====
 * Monday 9/24 is holiday (Autumn Equinox).
 * Mark, Hirata-san, Fabian, Kozu-kun, Panwei at Kamioka Tue-Fri.
==== 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 Info ====
 * Mark: 8/13-16.
 * Hirata-san: 8/13-17
 * Terrence: 8/24-26 f2f, then returns to Hong Kong.
 * Enzo: 9/14 JPS, 9/15 through 10/8 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 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.

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)