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==== Past week report ==== At Kamioka (Mark, Fabian, Enzo, Hirata-san): |
==== Report for week of 1/29 ==== * We moved the top filter intended for SR2 (#1) into the SR3 cleanbooth. * Unfortunately we noticed one of the blades had many small X-shaped stress fractures on the top surface (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=4058|4058]]). * We moved the top filter entered for SR3 (#3) into the SRM cleanbooth and inspected the blades. Two had one smallish stress fracture each and one had a huge fracture and looks close to failing (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=4061|4061]]). * We referred the BS OL. * We removed the BS tank lid and inspected the BS top filter blades. They seemed fine. * Hirata-san received and washed some ferromagnetic disks for IM flags and other small parts. * Hirata-san moved the BF with the tilted keystone (#1) out of the cleanbooth in preparation for rebuilding. * Hirata-san * Fabian measured the gain of the ADC system (homework from the Commissioning Workshop). |
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* Inspected LLB in tank - in a good position, but not very clean - apparent water spots and dirt. * Found the geophone adapter plates. * Retested SF FR stepper - still good. * Finally got SF LVDT working: * Found a short in the primary coil due to Al foil used for mechanical reinforcement at vacuum feedthrough connection. * Did a full calibration and found that linear range was too small (0.75 mm!) and did not cover nominal keystone height. * Decreased gain to increase linear range. * Adjusted the height of the yoke and secondary coil unit to center the linear region around the nominal keystone height. * Implemented velocity damping. * Found all parts for the LBB and damper rings. * Cu segments and some other parts were very dirty - wiped carefully for now, but should be properly cleaned before final install. * Outrigger parts for LBB have M16 thread cut directly into Al but should have had M16 helicoils. This is a galling risk with Ag-coated rod receptacles. Hirata-san organized rework. * Some special lock nuts are in short supply and are being borrowed from supply at ATC for next batch of BFs. * Made remaining two geophone in-air descrambler cables (total three). * Installed a thermometer supplied by Kokeyama-san on the tower around the BS tank. * Prepared the SF damper. * Designed a pattern of magnets for the two-segment arrangement of SF damper and laid it out on the magnet ring with the template. * Moved the Cu segments on SF cap by 30° (the cap had not been in the right position earlier). * Reinstalled PI: * Raised the PI with the crane and hooked the SF damper ring. Some of the rods did not fit the receptacles due to tolerance issue, but by going through a large number of rods and receptacles, we found three working sets. * Craned the PI onto the frame and suspended the SF/... section, this time with the hex cable clamp on the F0-SF rod. * Tensioned the PI yaw return spring, installed (but did not cable) the yaw stepper and adjusted the yaw of the SF/... section. We worry the return spring is not stiff enough. * Installed (but did not cable) the geophones. * Recentered the IP. The extra weight from the geophones (≈42 kg) and SF damper ring (≈17 kg) had brought the IP to near the point of instability, so we removed one arc weight (≈17 kg) and rearranged the other two in the top row to be symmetrical. * Added ballast to set the height of the F0 keystone. We now have about 6 kg in hand (due to removing one of the Cu segments for the SF damper). This should be enough margin for cables, temperature fluctuations etc. |
==== Plan for week of 1/29 ==== * Enzo at Mitaka 1/29 and most of 1/30, then vacation. * Kozu-kun away. * All others at Kamioka. * Make in-air pico adapter cables. * Test IM picos and BF yaw pico. * Test FR. * Calibrate LVDT. * Get screws for ballast mass from Takahashi-san. * Install ballast mass in BF. * Set up for F0 test. * Lower IM crossbars in SR3 assembly frame. * Open curtain on SR3 crane slot. * Set up dummy load (weight carrier, rods etc). * Do F0 test. * Bring in F0. * Hook up dummy load. * Adjust dummy load. |
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==== Plan for coming weeks ==== For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]]. |
==== Plan for week of 2/5 ==== * Enzo on vacation; all others at Kamioka. * Build IRM around IM. * Cable/test/adjust IM OSEMs. * Time permitting, do TFs from IM OSEMs to themselves and to optical sensor. |
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Weeks of 5/22, 5/29: * Retest SF stepper every day, to see if problems recur. * Find/install geophone adapter plates or improvise replacement. * Reinstall PI, this time with rods and damper ring. * Reinstall PI-SF rod, this time with hex cable clamp. * Cable/test PI geophones LVDTs and steppers. * Reinstall LBB blade units. |
==== Plan for week of 2/12 ==== * Enzo on vacation; all others at Kamioka. |
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==== Vacation Info ==== * Enzo 1/30-2/19 (at Mitaka 1/29, part of 1/30) * Kozu-kun 1/29-2/2 |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
Type B (Mark)
Report for week of 1/29
- We moved the top filter intended for SR2 (#1) into the SR3 cleanbooth.
Unfortunately we noticed one of the blades had many small X-shaped stress fractures on the top surface (klog 4058).
We moved the top filter entered for SR3 (#3) into the SRM cleanbooth and inspected the blades. Two had one smallish stress fracture each and one had a huge fracture and looks close to failing (klog 4061).
- We referred the BS OL.
- We removed the BS tank lid and inspected the BS top filter blades. They seemed fine.
- Hirata-san received and washed some ferromagnetic disks for IM flags and other small parts.
- Hirata-san moved the BF with the tilted keystone (#1) out of the cleanbooth in preparation for rebuilding.
- Hirata-san
- Fabian measured the gain of the ADC system (homework from the Commissioning Workshop).
Plan for week of 1/29
- Enzo at Mitaka 1/29 and most of 1/30, then vacation.
- Kozu-kun away.
- All others at Kamioka.
- Make in-air pico adapter cables.
- Test IM picos and BF yaw pico.
- Test FR.
- Calibrate LVDT.
- Get screws for ballast mass from Takahashi-san.
- Install ballast mass in BF.
- Set up for F0 test.
- Lower IM crossbars in SR3 assembly frame.
- Open curtain on SR3 crane slot.
- Set up dummy load (weight carrier, rods etc).
- Do F0 test.
- Bring in F0.
- Hook up dummy load.
- Adjust dummy load.
Plan for week of 2/5
- Enzo on vacation; all others at Kamioka.
- Build IRM around IM.
- Cable/test/adjust IM OSEMs.
- Time permitting, do TFs from IM OSEMs to themselves and to optical sensor.
Plan for week of 2/12
- Enzo on vacation; all others at Kamioka.
Vacation Info
- Enzo 1/30-2/19 (at Mitaka 1/29, part of 1/30)
- Kozu-kun 1/29-2/2