Differences between revisions 147 and 203 (spanning 56 versions)
⇤ ← Revision 147 as of 2017-05-26 13:29:23 →
Size: 3633
Editor: MarkBarton
Comment:
← Revision 203 as of 2017-11-10 09:54:31 → ⇥
Size: 1089
Editor: MarkBarton
Comment:
Deletions are marked like this. Additions are marked like this.
Line 6: Line 6:
==== Past week report ====
At Kamioka (Mark, Fabian, Enzo, Hirata-san):		 ==== Past two weeks report ====
At Kamioka (Mark, Enzo, Kozu-kun):
 * Supported IA team.
 * Replaced LPCDs for IM OSEMs with HPCDs for increased pitch/yaw range.
 * Re-zeroed OL after significant change of beam position during IA.
 * Re-laid-out OL to improve focus of lens to LEN QPD.
 * Offloaded the pitch/yaw actuation at the IM OSEMs using the IM pitch/yaw picos.
 * Enzo worked on design of control loops using the OL.
 * Kozu-kun worked on diagonalizing the OL.
Line 9: Line 16:
 * 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.		 Mitaka (Fabian, Hirata-san):
 * Hirata-san published his inventory of SR parts on Dropbox.
Line 35: Line 19:
==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].		 ==== Plan for week of 11/13 ====
Line 38: Line 21:
Week of 5/29, 6/6:
 * Cabling:
  * Route BF/... cabling up past SF to PI.
  * Route SF cabling up to PI.
  * Add Type 3 extensions to SF/... cables.
  * Move vacuum flanges to positions on assembly frame more convenient for next stage (accessible from second floor, one on each corner of frame).
  * Move in-air cabling to match flange positions.
  * Cable and test PI vertical LVDT.
  * Calibrate PI vertical LVDT.
  * Set yoke on PI vertical LVDT (if necessary).
  * Cable and test PI yaw stepper.
  * Cable and test PI vertical stepper.
  * Cable and test PI horizontal steppers.
  * Cable and test PI horizontal LVDTs.
  * Calibrate PI horizontal LVDTs.
 * Crane into tank.		 Kamioka: Mark
 * Attend commissioning workshop at U Toyama.
 * Be person-on-site for BF work.
 * Set up for mirror gluing.

Mitaka: Fabian and Hirata-san
 * SR procurement.
 * New PI GAS FR design.
 * BS LBB ballast mass design.
 * SR cable lamp design.

Mitaka: Enzo and Kozu-kun (Wed, Thu)
 * Servos
 * TFs of BF
 * Documentation

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past two weeks report

At Kamioka (Mark, Enzo, Kozu-kun):

  • Supported IA team.
  • Replaced LPCDs for IM OSEMs with HPCDs for increased pitch/yaw range.
  • Re-zeroed OL after significant change of beam position during IA.
  • Re-laid-out OL to improve focus of lens to LEN QPD.
  • Offloaded the pitch/yaw actuation at the IM OSEMs using the IM pitch/yaw picos.
  • Enzo worked on design of control loops using the OL.
  • Kozu-kun worked on diagonalizing the OL.

Mitaka (Fabian, Hirata-san):

  • Hirata-san published his inventory of SR parts on Dropbox.

Plan for week of 11/13

Kamioka: Mark

  • Attend commissioning workshop at U Toyama.
  • Be person-on-site for BF work.
  • Set up for mirror gluing.

Mitaka: Fabian and Hirata-san

  • SR procurement.
  • New PI GAS FR design.
  • BS LBB ballast mass design.
  • SR cable lamp design.

Mitaka: Enzo and Kozu-kun (Wed, Thu)

  • Servos
  • TFs of BF
  • Documentation

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