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| ==== Report for week of 11/12 ==== * BS * Kozu-kun noticed the BS OL was out of range, and Fabian and Fujii-kun investigated. It turns out that the temperature has risen by over 2°C, so all the GAS filters have sagged and several stages are touching. Miyoki-san and Furuta-san are looking at what can be done. * We ordered three more geophone cables in the standard (non-flipped pinout) to save time during the December vent, where we will replace at least two of the preamps to fix issues and take the opportunity to put in non-flipped ones. * SRM * We cabled all the SF/... through to the rack and checked that all items worked. * We did the vertical height survey and found that as with SR2 and SR3, the chain is longer than the CAD, this time by ≈7 mm, and again mostly between the SF and BF. We decided on a keystone height of 11.5 mm (5 mm higher than CAD), which can be achieved with 1 kg more on the SF and 1 kg in reserve for a yaw stepper mechanism. We reset the height of the yoke to give near-zero LVDT output for the new nominal height, and corrected the sensing and actuation signs, but still need to do the calibration. * The final SRM small glass mirror became available, so we had Hirose-san ship it to us so we can install it while the suspension is still on the assembly frame. Hirata-san ordered shims to make up the new recommended thickness of 1.4 mm and a micrometer to check the combination, which should arrive on Monday 11/26. * Enzo took calibration data for the last batch of geophones, for SRM. We had to borrow cables from SR2 because one cable was missing and another was miswired. And it turned out that one of the SR2 cables was defective as well. But if we can find two possibly borrowed by Okutomi-san and rewire one, we should have enough for SR2 and SRM. The geophones appear to be healthy and we will seal them next week. * We raised the PI clear of the assembly frame and unlocked and centered the IP. We calibrated the IP LVDTs, and reversed connections to get positive LVDT output for positive yaw. We borrowed a HPCD from SR3-IM-V for the SRM IP but haven't checked the actuation yet. * SR2 * While we were grabbing geophone cables from SR2, we added extra arc weights to get the IP frequency below 0.1 Hz. * Akutsu-san showed us how to install the OL transmitter support pillar, receiver shelf and viewports. We believe we have the parts to finish setting up the SR2 OL. ==== 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)]] |
==== Report for the week of 3/11 ==== * Fabian mostly helped Fujii-kun with the PRM. * Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small. * 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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| ==== Plan for week of 11/26 ==== * SRM * Clean tools and metal parts for final SRM glass mass. * Swap in final glass mass. * Adjust SF trim mass. * Check/adjust alignment of SS. * Calibrate IP LVDTs. * Add arc weights and geophones. * Improve centering/tuning of IP and SS alignment. * Disconnect cables at feedthroughs, lock suspension. * Crane into tank. * SR2 * Finish OL setup * TFs. * Control loops. ==== Plan for week of 12/3 ==== * f2f Meeting at NAOJ - no Kamioka work. ==== Plan for week of 12/10 ==== * Prepare for vent of BS. * BS work - see [[KAGRA/Subgroups/VIS/TypeB/ToDoBS]]. |
==== 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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| ==== Vacation/Event Info ==== * Hirata-san at Mitaka, Fri 11/30 (medical check for solvent use). * Enzo at Mitaka, Fri 11/30 (Mitaka day). |
==== 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.
- Fabian monitored the SRM yaw drift. It gradually reversed but so far remained small.
- 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.