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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 the week of 3/11 ==== * Fabian mostly helped Fujii-kun with the PRM. * 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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| ==== 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. |
==== Plan for week of 3/11 ==== * Mark at Kamioka full week. * Enzo at Kamioka Mon, Tue, then JPS. * Hirata-san at Kamioka from Monday lunchtime through Friday. * Fix BS. * Final test of stepper remote enable system (someone in cleanroom checks the lights go on/off). * Continue monitoring SRM yaw drift. * More mode Q measurements. * Work on Type B paper. |
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| ===== 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. |
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| ==== 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). ===== 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 * 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. * 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. ===== 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 mostly helped Fujii-kun with the PRM.
- 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 3/11
- Mark at Kamioka full week.
- Enzo at Kamioka Mon, Tue, then JPS.
- Hirata-san at Kamioka from Monday lunchtime through Friday.
- Fix BS.
- Final test of stepper remote enable system (someone in cleanroom checks the lights go on/off).
- Continue monitoring SRM yaw drift.
- More mode Q measurements.
- Work on Type B paper.
Vacation/Travel Info
- Enzo at JPS then final vacation, 3/13-29
- Terrence's last day, 3/29.