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| ==== Report for week of 7/2 ==== * We double-checked the bounce frequency and it was indeed around 0.5 Hz with the CuBe auxiliary spring installed. * We prepared (but did not yet install) 6 arc weights for tuning the IP. * We unlocked the security structure from the assembly frame, and raised the whole system on the top jacks. We then unlocked the IP and adjusted the leveling so the IP was centered. We then had to loosen two of the poles at the top level of the security structure to make it vertical again, because it turns out that the jack receptacles (which also serve as the IP leg bases) are welded at very uneven depths in the bottom surface of the PI, so the IP and the bottom surface can't be level at once. * We debugged an issue with the height of the payload. It turns out that due to a buildup of errors (especially an extra 3 mm between the SF and BF), the payload is some 5-6 mm low with the F0 keystone at CAD height. Since the frequency is roughly independent of height around 0.5 Hz, we decided to go with a higher F0 keystone. * Enzo and Eleonora routed all the SF/... cables up to the PI. * We found we needed 4.7 kg of extra mass to get the desired keystone height, so we decided to put the third Cu segment (3.3 kg) back on, purely as ballast. * We put some extra small masses on the SF cap to level it. The suspension is now fully ballasted and trimmed except for 1 Promec mass (455 g) standing in for the new PI yaw stepper motor assembly (estimated 330 g) which is yet to arrive. * We took all the SR sat amps back to Mozumi to get new capacitors installed, and grabbed three spares for use while that is being done. * We investigated and documented Tanaka-san's watchdog for the BS, to see if the BIO Converter chassis that it uses could also drive reset lines for stepper motor driver boxes. * Hirata-san and Terrence characterized the last 4 F0 blades. * Hirata-san and Terrence installed blades in the top filter for SR2 and tuned it to 0.5 Hz (with the CuBe auxiliary spring) over three rounds of compression. |
==== 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. |
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| ==== Plan for week of 7/9 ==== * Mark, Enzo, Hirata-san, Kozu-kun, Terrence at Kamioka Mon-Fri. * -- ===== Main Sequence ===== * Check/restore alignment of payload, especially optic pitch. * Install and cable geophones. * Install arc weights. * Tune IP. * Install, cable PI yaw stepper. * Make three in-air stepper splitter cables for SR2, SR3 and SRM. * Calibrate PI LVDTs and FRs. * Cabling, testing, TFs. ===== F0/LBB Stuff ==== * Finalize PI #1 for SR2; crane into SR2 cleanbooth. * Remove SR3 tank lid, crane LBB rings to top of lower half of the tank, clamp in position. * Set tank jacks to nominal height. * Clear space for PI #2 (SRM) work. === Plan for week of 7/16 === ===== Main Sequence ===== * Lock suspension. * Crane into tank. * Unlock suspension. * Rearrange cables. * Test. ===== F0/LBB Stuff ===== * Install correct IP in PI #2. * Crane PI #2 to second floor. * Rebuild top filter of PI #2. ==== 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 ==== * 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.