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| ==== Report for week of 2/12 (February 12th) ==== * On Saturday we moved the vertical IM OSEMs in order to compensate for a large pitch in the IM introduced when the IR laser as aligned. * I took transfer functions over the weekend and the system looks healthy. * Although moving the OSEMs was done successfully, I accidentally pulled the cables and moved the flying saucer cable clamp set. I rotated it back judging the position by visual inspection, but an IM yaw drift appeared since then. It's moving with a speed of 0.2 urad/min. * On Tuesday we moved the Im back to zero but the drift continued. At the time of writing these lines it is at -833 urad, with H2 and H3 at 93 um and 47 um and still drifting. * On Saturday we connected the SRM geophones in-air cables and confirmed we had a signal. * However, on Wednesday morning the geophones are not giving any signal. We cheked the master model channel and realized the problem was not the slave model. We suspect a hardware fault. * I checked the in-air cables were connected. * We released the SRM optical bench and wiped the places where sticky tape was used to fix support blocks. * We wiped the SR2 optical bench and security structure. SR3 and SRM had been wiped by Hirose-san, Hirata-san and Fujii-kun. * Terrence worked on splitting the real-time models for all the SR suspensions. * Today the pumping down of the central area will begin around noon. We will monitor the four inverted pendulums. |
==== 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 1/28 ==== * Etc * Mark inventoried lots of items and updated the [[KAGRA/Subgroups/VIS/TypeB/Status|Status]] page. * SR2 * Hirata-san helped with installing the obelisk on the LBB, and added counterweights to get the LBB level and at the right height for the first rough alignment. However the springs were still at or near the top stops, so he later pulled down the LBB with excess mass, locked the blades at the bottom of their range and reset the LBB rods and damping magnet ring, aiming off by 10 mm so that it would be correct when the LBB was allowed to rise to midrange on the blades. He left it pressed down for now so that Hirose-san could apply FC. Early next week he will release it and do the final ballasting. * Hirose-san applied and removed FC on both sides of the optic for cleanliness. * Mirapro hooked the LBB. * SR3 * Enzo installed IM damping filters. * Mark installed a BIO Converter for the stepper remote enable (which will eventually also be used for the WD). * Fabian researched buoyancy compensation and pre-applied as much as possible to SR3. The total compensation needed is 0.19 mm for F0, 0.48 mm for SF and 0.46 mm for BF, total 1.23 mm. 1.0 mm had been applied with the jacks. The initial plan was to apply the calculated amounts at each level but then offset F0 1.0 mm lower to undo the jack adjustment. However SF was stuck approximately 1 mm lower than it needed to end up, so the buoyancy correction for it will have to be done at F0, and F0 will end up quite close to nominal. * Fabian also offloaded the IM pico yaw adjustment done by Enomoto-kun-tachi to the F0 yaw stepper. This left the OSEMs well-centered, so we will not need to adjust them and the LBB can be released. * SRM * Enzo fixed the broken triple in-air pico adapter cable and we plugged it back in. * Fabian calibrated the F0 FR. * Enzo and Terrence installed the arc weights and geophones, tuned and centered the IP, and centered and calibrated the FRs. * Mirapro helped us with the camera viewport issue by giving us a gasket of the same type but a different brand from their stock, which snapped easily into place. We then installed the viewport on the tank. Kokeyama-san will help us add the camera and camera LAN cable next week. * Simon gave us all the remaining items for the SRM OL except the 3D stage for the LEN QPD. |
==== 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 2/4 ==== * Mark, Enzo, Fabian, Terrence at Kamioka Mon-Fri. * Hirata-san at Kamioka Mon+TBD. * Etc * Split SR2, SR3 and SRM RT models. * Get rid of the power reel behind SRM and plug stuff into the new power point instead. * BS * Run BNC cables for stepper remote enable, plug into BIO, debug. * SR2 * Do buoyancy correction. * Install camera viewport. * Install camera. * Run BNC cables for stepper remote enable, plug into BIO, debug. * SR3 * Release LBB. * Ballast LBB. * Install camera viewport. * Install camera. * Debug stepper remote enable. * SRM * Install camera. * Ballast LBB. * Do buoyancy correction. * Set up OL. * Debug stepper remote enable. |
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| * Constitution Day, 2/11. * Mark and Enzo at KIW in Perugia, 2/12-18. * Enzo vacation, 3/5. * Enzo et al. Farewell Party, 3/7. |
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.