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==== Report for week of 7/30 ====
===== SR3 =====
 * We undid the accidental misalignment of the SR3. We also switched off the BF GAS offset we had been using, let the IM rise until near zero on the BF LVDT, and adjusted the IM vertical OSEMs back to mid-range.
 * We closed control loops for the SR3 GAS filters.
 * Terrence set up the LED and TILT QPD for the final OL, and did a new calibration.
===== SR2 =====
 * We installed the SR2 SF damper magnet ring but found that the magnet pattern didn't match the Cu segments due to a different in the caps between SR3 and SR2. We raised the ring but left it suspended, clamped the template to the underside and rearranged the magnets.
 * We did a vertical height budget of the SR2. It turns out to have a very similar issue to the SR3: the chain is about 5 mm longer than the CAD, with about 3 mm of that between the SF and BF. We decided to do the same fix and operate with the F0 keystone 5 mm higher. We chose an total amount of ballast to give that keystone height and secured most of it to the SF, keeping a reserve for cables and the yaw stepper.
 * We routed most (all?) of the SF/... cabling up to the PI.
==== Report for the week of 3/11 ====
 * Fabian helped Fujii-kun with the PRM most of the week. Hirata-san also helped at various times.
 * Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small. We will try resetting it to zero with the pico and see if the trend changes.
 * Mark and Hirata-san debugged the BS:
  * We inspected the payload section and quickly found the problem: two RM EQ stops were touching, on the +L (-X,+Y) side at the top. This was probably because the stops had been adjusted with the IP unlocked and sitting a few mm to -L, whereas now we have the DCCTRL running and have been locking the IP at the LVDT zero. We drove the IP to L=+1.5 mm as a near-worst case, and backed off all the stops to give several mm of margin. Then we zeroed the IP pitch, roll and yaw with the picos.
  * We also opened the top of the BS and confirmed that the mechanical zero defined by the locking mechanism agreed with the LVDT zero. It was very close in L and T, but -728 µrad in Y, driven mostly by a -805 µm offset in H3. That much is probably not a dumb error but just a difference in technique among the three people using calipers to take data for the calibration.
  * We then prepared the BS for close-up:
   * We wiped and inspected the O-ring for the lid and replaced the lid.
   * We wiped all accessible surfaces in the lower half of the tank, rescued some dropped items (some PEEK tube and a small nut) and un-immobilized the LBB.
  * After all the above, the OL was a bit off-center but still on the QPD, and Nagano-san fairly quickly recovered the original alignment.
 * Terrence rebuilt the BS OL according to a new layout suggested by Simon, which avoids scrambling the pitch/yaw at the first steering mirror and greatly reduces the amount of diagonalization required.
 * Terrence noticed some anomalous cross coupling on the SR2 (but not the SR3) and we investigated.
  * We suspected it might be an odd position of the beam spot on the optic, so we took pictures through the camera and LED viewports of SR3, and opened the SR2 tank and used a white target, but the beam spots were in very similar positions - close to central vertically and about 3 cm to the left of center horizontally.
  * We suspected it might be something touching at the IRM (because the IM OSEM TFs were fine), so we checked using a stick mirror with the IP centered, but all EQ stops were well backed off.
  * We suspected it might be a ghost beam from the LEN/TILT beamsplitter (and one was clearly visible on the SR2 TILT QPD) so Terrence set up a beam block, which improved things slightly but not completely.
  * Finally Terrence discovered that the problem was mainly uneven sensitivities of the QPD quadrants, and devised a new calibration and diagonalization procedure which allowed for it.
 * Enzo and Terrence did a health check of the SRM and it was fine except for some apparent electrical noise around 240 Hz. They put in a notch filter to get rid of it for now.
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===== SRM =====
 * We moved the SRM assembly frame into its final position, reset it to the initial configuration, double-checked the heights of the crossbars, and lowered the optical table by 3 mm (to give margin for the optic to rise during hanging, which we had kept forgetting to do). We cleaned it up with the airgun and wet-wipes. We installed the IM ring and IM.
 * We assembled the SRM metal mass. Hirata-san made a jig from a plate with 4 screws which could safely hold the delicate front Sol-Black-coated ring upside down while the rest of the components were mounted on it.
 * We moved the metal mass to the mirror box and added the prisms and magnet standoffs. We applied the EP30 on Friday morning, but probably won't be able to check the result until after Obon.
==== Plan for week of 3/18 ====
 * Mark, Fabian, Terrence at Kamioka full week.
 * More OL stuff.
 * SRM controls and Guardian.
 * Reset SRM yaw and continue monitoring yaw drift.
 * Assist with pump down.
 * Work on Type B paper.
 * Tidy up.
  * Throw out foil and other garbage.
  * Gather and clean tools.
  * Gather and organize unused parts and fasteners.
  * Pull out unused cables in cable tray near SR3.
  * Return all unused cables to tent.
  * Tidy up cables in rear of SR2 rack.
  *
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==== Plan for week of 8/13 ====
 * KAGRA closed Mon, Tue.
 * Mark on vacation Mon-Thu, then Mitaka on Friday.
 * Enzo, Fabian, Terrence, Panwei, Rikako at Kamioka Wed-Fri. Probably no tunnel work.
 * Hirata-san on vacation all week.
 * TFs with new OL.
 * Controls work.
 * Tune SR3 IP?
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==== Plan for week of 8/20 ====
 * Mark, Enzo, Hirata-san, Fabian, Kozu-kun, Terrence, Panwei at Kamioka Mon-Fri.
 * Enzo, Hirata-san, Fabian, Kozu-kun, Terrence, Panwei at Kamioka Mon-Thu, then f2f.
 * Kozu-kun works at Mozumi Mon.
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===== SR3 =====
 * Hook LBB, add ballast mass.
 * Tune IP.

===== SR2 =====
 * Adjust ballast/trim mass, with reserve for yaw stepper.
 * Cable/test PI items (LVDTs, steppers, geophones).
 * Set damper height.
 * Add arc weights, adjust IP.
 * Stage LBB damper rings in tank.
 
===== SRM =====
 * Check gluing result - redo if necessary.
 * Assemble RM.
 * Add IM ballast masses (we forgot this before).
 * Get parts from AOL and set up new pitch-setting OL.
 * Hang metal mass.
 * Hang RM.

==== 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)]]

==== 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.
==== Vacation/Travel Info ====
 * Enzo at JPS then final vacation, 3/13-29
 * Terrence's last day, 3/29.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for the week of 3/11

  • Fabian helped Fujii-kun with the PRM most of the week. Hirata-san also helped at various times.
  • Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small. We will try resetting it to zero with the pico and see if the trend changes.
  • Mark and Hirata-san debugged the BS:
    • We inspected the payload section and quickly found the problem: two RM EQ stops were touching, on the +L (-X,+Y) side at the top. This was probably because the stops had been adjusted with the IP unlocked and sitting a few mm to -L, whereas now we have the DCCTRL running and have been locking the IP at the LVDT zero. We drove the IP to L=+1.5 mm as a near-worst case, and backed off all the stops to give several mm of margin. Then we zeroed the IP pitch, roll and yaw with the picos.
    • We also opened the top of the BS and confirmed that the mechanical zero defined by the locking mechanism agreed with the LVDT zero. It was very close in L and T, but -728 µrad in Y, driven mostly by a -805 µm offset in H3. That much is probably not a dumb error but just a difference in technique among the three people using calipers to take data for the calibration.
    • We then prepared the BS for close-up:
      • We wiped and inspected the O-ring for the lid and replaced the lid.
      • We wiped all accessible surfaces in the lower half of the tank, rescued some dropped items (some PEEK tube and a small nut) and un-immobilized the LBB.
    • After all the above, the OL was a bit off-center but still on the QPD, and Nagano-san fairly quickly recovered the original alignment.
  • Terrence rebuilt the BS OL according to a new layout suggested by Simon, which avoids scrambling the pitch/yaw at the first steering mirror and greatly reduces the amount of diagonalization required.
  • Terrence noticed some anomalous cross coupling on the SR2 (but not the SR3) and we investigated.
    • We suspected it might be an odd position of the beam spot on the optic, so we took pictures through the camera and LED viewports of SR3, and opened the SR2 tank and used a white target, but the beam spots were in very similar positions - close to central vertically and about 3 cm to the left of center horizontally.
    • We suspected it might be something touching at the IRM (because the IM OSEM TFs were fine), so we checked using a stick mirror with the IP centered, but all EQ stops were well backed off.
    • We suspected it might be a ghost beam from the LEN/TILT beamsplitter (and one was clearly visible on the SR2 TILT QPD) so Terrence set up a beam block, which improved things slightly but not completely.
    • Finally Terrence discovered that the problem was mainly uneven sensitivities of the QPD quadrants, and devised a new calibration and diagonalization procedure which allowed for it.
  • Enzo and Terrence did a health check of the SRM and it was fine except for some apparent electrical noise around 240 Hz. They put in a notch filter to get rid of it for now.

Plan for week of 3/18

  • Mark, Fabian, Terrence at Kamioka full week.
  • More OL stuff.
  • SRM controls and Guardian.
  • Reset SRM yaw and continue monitoring yaw drift.
  • Assist with pump down.
  • Work on Type B paper.
  • Tidy up.
    • Throw out foil and other garbage.
    • Gather and clean tools.
    • Gather and organize unused parts and fasteners.
    • Pull out unused cables in cable tray near SR3.
    • Return all unused cables to tent.
    • Tidy up cables in rear of SR2 rack.

Vacation/Travel Info

  • Enzo at JPS then final vacation, 3/13-29
  • Terrence's last day, 3/29.

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