Differences between revisions 146 and 160 (spanning 14 versions)
⇤ ← Revision 146 as of 2017-05-26 10:54:56 →
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Editor: MarkBarton
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← Revision 160 as of 2017-06-30 13:26:16 → ⇥
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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, Enzo, Simon, Type Bp team):
 * Mark remade the BF pico adapter cable which was poorly made and had also been damaged.
 * The Type Bp team tided up the BS rack and made new labels for many cables (thanks!).
 * Enzo connected up the in-air cables for the picos and steppers.
 * Mark and Enzo renumbered the PI LVDTs, geophones and LVDTs to make a consistent scheme working anticlockwise.
 * Enzo and Mark debugged all the cables. The only problem we couldn't solve was that the actuator coil for PI LVDT #0 is open-circuit at the connector on the LVDT. (It has been intermittent but worked before the craning.) We may have to redo the connector or replace the LVDT. Limited TFs will be possible in the next week.
 * Simon set up the LSOL and was easily able to get a return beam from the mirror on the dummy BS.
 * Shoda-san copied over the LSOL section of the PR3 real-time model into the BS model and made other improvements (thanks!).
 * Mark brought home
Line 9: Line 17:
 * 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.		 At Mitaka (Fabian, Hirata-san):
 * Fabian finished designing final trim masses for IM/BF/SF for the final hang of the BS and passed it to Hirata-san to make drawings and get quotes.
 * Hirata-san requested quotes for the replaceable-jaw version of the BS wire clamps.
 * Fabian and Hirata-san gathered needed items for the BS prism/flag gluing.
 * Hirata-san designed receptacles for the new rods with 8 mm heads and requested quotes.
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==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].

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 7/3 ====
 * Do prism/flag gluing on real BS at Kashiwa (whole team).
 * Do new 3D CAD (Hirata-san):
  * SR2 on BS assembly frame. (Adjust jack positions if possible, or leave for Fabian/Mark to do.)
  * Final BS build, SS/PI/SF as for Test Hang but with BF/IRM/IM/BS/RM down rotated back to original direction.
   * On-assembly-frame version. (Adjust jack positions if possible, or leave for Mark to do.)
   * In-tank version.
 *
==== Plan for week of 7/10 ====

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past week report

At Kamioka (Mark, Enzo, Simon, Type Bp team):

  • Mark remade the BF pico adapter cable which was poorly made and had also been damaged.
  • The Type Bp team tided up the BS rack and made new labels for many cables (thanks!).
  • Enzo connected up the in-air cables for the picos and steppers.
  • Mark and Enzo renumbered the PI LVDTs, geophones and LVDTs to make a consistent scheme working anticlockwise.
  • Enzo and Mark debugged all the cables. The only problem we couldn't solve was that the actuator coil for PI LVDT #0 is open-circuit at the connector on the LVDT. (It has been intermittent but worked before the craning.) We may have to redo the connector or replace the LVDT. Limited TFs will be possible in the next week.
  • Simon set up the LSOL and was easily able to get a return beam from the mirror on the dummy BS.
  • Shoda-san copied over the LSOL section of the PR3 real-time model into the BS model and made other improvements (thanks!).
  • Mark brought home

At Mitaka (Fabian, Hirata-san):

  • Fabian finished designing final trim masses for IM/BF/SF for the final hang of the BS and passed it to Hirata-san to make drawings and get quotes.
  • Hirata-san requested quotes for the replaceable-jaw version of the BS wire clamps.
  • Fabian and Hirata-san gathered needed items for the BS prism/flag gluing.
  • Hirata-san designed receptacles for the new rods with 8 mm heads and requested quotes.

Plan for week of 7/3

  • Do prism/flag gluing on real BS at Kashiwa (whole team).
  • Do new 3D CAD (Hirata-san):
    • SR2 on BS assembly frame. (Adjust jack positions if possible, or leave for Fabian/Mark to do.)
    • Final BS build, SS/PI/SF as for Test Hang but with BF/IRM/IM/BS/RM down rotated back to original direction.
      • On-assembly-frame version. (Adjust jack positions if possible, or leave for Mark to do.)
      • In-tank version.

Plan for week of 7/10

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