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| ==== Report for week of 10/1 ==== ===== SR2 ===== * We solved a mystery with the height of the BF keystone: it turns out that running the table KOACH filters in the tank warms it up (by about 1.5°C) and causes significant sag (700 µm). D'oh! * We ran power to the pico drivers. * We got the lower section of the SR2 fairly well aligned with just a bit of adjustment with the IM pitch and roll picos. * We helped Lucia double-check the geometry of the IP - the current matrix calculation assumes the FRs and the LVDT sensors and actuators are colocated, which is much closer to true than for the BS, but not quite right. * We gave up on doing anything more with SR2 for now because we're waiting on extra extension cables for the PI and Fujii-kun will want to borrow one of the geophones next week for a huddle test with new geophones. ===== SRM ===== * We set the pitch of the SRM and RM, tightened the clamps and removed the winch system. * We installed the BF crossbars of the assembly frame and the BF ring section of the security structure. * We lifted the IM/... section on the load gauge to find its weight. * We craned in the BF and removed the cap. * We installed the BF-IRM rods and the IRM top plate. * We installed the BF-IM maraging rod and flying saucer cable clamps. * We suspended the IM/... section and adjusted the trim masses for balance and total mass. It took quite a lot of adjustment in each of pitch, roll and vertical. The vertical was due to the fact that the weight of the IM/... section is very close to that of SR2/SR3 but the SRM BF is about 0.5 kg weaker. The roll was due to the fact that the default configuration of trim mass had no correction for the horizontal wedge on the optic. However the pitch is a bit of a mystery - nearly all of the removed mass had to come off the AR side. Fortunately we were able to correct for it entirely with masses we had in hand. * We routed the TM OSEM cables via the flying saucer up to the underside of the BF. * We got 2 power supplies from Shimode-san so we can fire up the SRM rack next week. He will also supply suitable cables to connect the power supplies to the DC power strip in the rack. * We received the replated yoke for the SRM top filter. |
==== 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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| ==== Plan for week of 10/8 ==== * Monday 10/8 is Sports Day. * Enzo returns Tuesday 10/9. * Mark and Terrence (plus TBD) at Kamioka Mon-Fri. * Enzo, Hirata-san, Fabian and Panwei at Kamioka Tue-Fri. ===== SR2/SR3 ===== * Terrence to set up LEN half of SR3 OL and, time permitting, TILT and LEN for SR2. ===== SRM ===== * Cable/test BF. * Install IRM. * Install/cable/test IM OSEMs. * Suspend/weigh/balance the BF/... section. |
==== 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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| ==== 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)]] |
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| ==== Vacation/Visitor Info ==== * Enzo: 9/15 through 10/8 vacation in Chile. * Terrence: 10/8-12, 10/29-11/2 at Kamioka. |
==== 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.