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| * Type B Past Week Summary - weeks of 8/22 and 8/29 * Fabian, Mark, Zhao-kun and Yokogawa-kun did BS installation at Kamioka: * Weighed the BF, SF and dummy BS (in mirror box). * Moved the geophones onto the optical table, clamped them down and took another time series for analysis. * Aligned the IM, installed the extra trim masses, tested the picos and weighed the whole assembly. * Placed vacuum flanges and cleaned D-Sub cables ready for routing to the rack. * Realigned and immobilized the optical table (which had been bumped). * Made safety improvements on the second floor (new safety rail, new arrangement of floor pieces, caution tape around holes) * Suspended the dummy BS. Currently however it is not hanging correctly, but is off in the +Y direction by several mm relative to the mirror box. * We set up the BS OL, using one of the wheeled chests of drawers as a base and using the OL breadboard from the PR2 assembly frame. * Hirata-san made a 3D assembly model for SR2 and added the optical design. * Hirata-san worked with Uchiyama-san to solve the 90° rotation problem. It turns out the "box" part with the pistons can be rotated, so we can build the SR2 according to the original design. * Hirata-san investigated the puzzle of the BF-IM maraging rods, where the 2D drawings and 3D CAD do not agree. Fortunately the actual parts seem to agree with the 3D CAD. * Hirata-san washed 3 OSEMs (last of initial 10 for BS) and parts for two BFs (for Type A). He moved the BF parts into the clean room and will assemble them with ATC staff from next Wednesday 9/7. * Type B ongoing issues * Longer cables for BF->PI and SF->PI - RECEIVED * Longer term to-do list * Decide position of BS rack - DONE * Do Inventor assembly for SR2 in chamber and on assembly frame (Hirata) - NEARLY DONE. * Write more of payload assembly procedure (Fabian) - ONGOING * Write more of BS Assembly Procedure [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=4235| E1504235]], [[https://onedrive.live.com/redir?resid=D5CCFA70A378E0D0!195&authkey=!AM_usynuo9QI57g&ithint=folder,webloc|E1504235 draft]] (Mark) - ONGOING * Lower breadboard installation to be incorporated into the procedure document. * Work on BS simulation (Fabian) * Do BS Simulink model (Mark, Kokeyama) * Do 2D drawings of SR2 parts (Hirata) * Redesign SRx IM wire clamps for larger prisms, remachined RMs * Order SRM/PRM parts (Hirata/Shoda) * Order SRx fasteners (Hirata) |
=== 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. |
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| * Terrence rebuilt the BS TILT 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. He started on the LEN OL, but unfortunately the QPD stage fell and bent the brackets holding two of the micrometers. It's useable but we haven't installed it yet. * 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 procedure which allowed for it. Later we discovered that one of the 3 dB gain stages on the whitening filter was engaged, even though the switch on the BIO Config card was not. It mysteriously came good after we removed and replugged the BIO Config card. * 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 low-pass 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 OL setup. * Recalibration of all OLs per new procedure. * Improve mounting of BS OL RX breadboard. * Reinstall BS LEN OL. * SRM controls and Guardian. * Reset SRM yaw and continue monitoring yaw drift. * Length/pitch decoupling. * 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. |
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 TILT 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. He started on the LEN OL, but unfortunately the QPD stage fell and bent the brackets holding two of the micrometers. It's useable but we haven't installed it yet.
- 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 procedure which allowed for it. Later we discovered that one of the 3 dB gain stages on the whitening filter was engaged, even though the switch on the BIO Config card was not. It mysteriously came good after we removed and replugged the BIO Config card.
- 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 low-pass 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 OL setup.
- Recalibration of all OLs per new procedure.
- Improve mounting of BS OL RX breadboard.
- Reinstall BS LEN OL.
- SRM controls and Guardian.
- Reset SRM yaw and continue monitoring yaw drift.
- Length/pitch decoupling.
- 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.