Differences between revisions 146 and 185 (spanning 39 versions)
⇤ ← Revision 146 as of 2017-05-26 10:54:56 →
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Editor: MarkBarton
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← Revision 185 as of 2017-09-01 14:32:36 → ⇥
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Editor: MarkBarton
Comment:
Deletions are marked like this. Additions are marked like this.
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At Kamioka (Mark, Fabian, Enzo, Hirata-san): At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Yoshioka-kun, Kozu-kun):
 * We solved the problem with the OSEMs: cables had been plugged into the confusingly named "PD current monitor" outputs (actually LED current monitors), not the "OSEM outputs".
 * We solved a problem with the real-time model freezing which turned out to be the IO chassis having lost power.
 * We took some mass off the IM to allow for the weight of the cables, and readjusted it in pitch and roll.
 * We aligned the IRM to the IM and set the OSEMs to mid-range.
 * We added ballast to the BF.
 * We changed the receptacles for the SF-BF rod. The low receptacle did not fit properly into the BF keystone and Hirata-san had to file it.
 * We fixed a broken wire on the BF yaw pico, retested the pico and added the BF cap.
 * We cabled and tested the BF cap picos.
 * We lifted the BF and weighed and balanced it.
 * We installed the SF ring and brought in the SF.
 * We installed the Cu segments on the SF.
 * We cabled the SF LVDT and did a quick test (not a full calibration).
 * We replaced non-vacuum compatible cables in the PI, removed various sticky labels and wiped it with ethanol.
 * We tried to hook the SF-BF rod but found the hole in the hex cable clamp was too small for the 8 mm rod head. We enlarged the hole but then found the PEEK pieces were too loose. We tried using foil, but then managed to lose a PEEK piece into the BF, so we will need to remove the cap of the BF to get it.
Line 9: Line 23:
 * 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 9/4 ====
Mark, Fabian, Enzo (Tue-Fri), Ohishi-san, Hirata-san, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun (Thu, Fri)
 * Retrieve PEEK piece from BF.
 * Crane SF back in.
 * Suspend BF/IRM/IM/RM/BS.
 * Test SF FR.
 * Calibrate SF LVDT.
 * Install SF cap; route cables.
 * Lift and weigh SF/BF/IRM/IM/RM/BS.
 * Adjust SF ballast.
Line 35: Line 34:
==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].		 ==== Plan for week of 9/13 ====
Mark (except Wed), Fabian (except ASJ), Enzo, Ohishi-san, Hirata-san, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun
 * Prepare magnet ring.
 * Bring in PI.
 * Route cables.
 * Suspend SF/..., adjust tilt of SF and total mass.
 * Adjust damper gap.
  
Line 38: Line 43:
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.

 
 		 ==== Vacation Info ====
Mark: 10/16-24

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past week report

At Kamioka (Mark, Ohishi-san, Fabian, Enzo, Hirata-san, Yoshioka-kun, Kozu-kun):

  • We solved the problem with the OSEMs: cables had been plugged into the confusingly named "PD current monitor" outputs (actually LED current monitors), not the "OSEM outputs".
  • We solved a problem with the real-time model freezing which turned out to be the IO chassis having lost power.
  • We took some mass off the IM to allow for the weight of the cables, and readjusted it in pitch and roll.
  • We aligned the IRM to the IM and set the OSEMs to mid-range.
  • We added ballast to the BF.
  • We changed the receptacles for the SF-BF rod. The low receptacle did not fit properly into the BF keystone and Hirata-san had to file it.
  • We fixed a broken wire on the BF yaw pico, retested the pico and added the BF cap.
  • We cabled and tested the BF cap picos.
  • We lifted the BF and weighed and balanced it.
  • We installed the SF ring and brought in the SF.
  • We installed the Cu segments on the SF.
  • We cabled the SF LVDT and did a quick test (not a full calibration).
  • We replaced non-vacuum compatible cables in the PI, removed various sticky labels and wiped it with ethanol.
  • We tried to hook the SF-BF rod but found the hole in the hex cable clamp was too small for the 8 mm rod head. We enlarged the hole but then found the PEEK pieces were too loose. We tried using foil, but then managed to lose a PEEK piece into the BF, so we will need to remove the cap of the BF to get it.

Plan for week of 9/4

Mark, Fabian, Enzo (Tue-Fri), Ohishi-san, Hirata-san, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun (Thu, Fri)

  • Retrieve PEEK piece from BF.
  • Crane SF back in.
  • Suspend BF/IRM/IM/RM/BS.
  • Test SF FR.
  • Calibrate SF LVDT.
  • Install SF cap; route cables.
  • Lift and weigh SF/BF/IRM/IM/RM/BS.
  • Adjust SF ballast.

Plan for week of 9/13

Mark (except Wed), Fabian (except ASJ), Enzo, Ohishi-san, Hirata-san, Yoshioka-kun (Tue, Wed, Fri), Kozu-kun

  • Prepare magnet ring.
  • Bring in PI.
  • Route cables.
  • Suspend SF/..., adjust tilt of SF and total mass.
  • Adjust damper gap.

Vacation Info

Mark: 10/16-24

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)