Differences between revisions 146 and 165 (spanning 19 versions)
⇤ ← Revision 146 as of 2017-05-26 10:54:56 →
Size: 3286
Editor: MarkBarton
Comment:
← Revision 165 as of 2017-07-14 07:14:06 → ⇥
Size: 2069
Editor: MarkBarton
Comment:
Deletions are marked like this. Additions are marked like this.
Line 7: Line 7:
At Kamioka (Mark, Fabian, Enzo, Hirata-san): At Kamioka (Mark, Enzo, Yoshioka-kun):
 * We experimented with rearranging the arc weights to accommodate the magic wands and came up with a suitable scheme.
 * We used spare arc weights as extra ballast on the LBB to get it to float, and measured the height for a known load.
 * We put the blocks back under the LBB and unhooked it.
 * We moved the suspension from the tank back to the assembly frame.
 * We craned the LBB rings down onto the LBB but did not remove them yet. (This however is the last crane work in the tank until reinstallation, so the lid does not have to come off again and the pallet can be used for the PI.)
 * We put the crossbars back in the assembly frame underneath the SF and BF (and corrected an error in the height of the BF ones).
 * Enzo started setting up the SR3 rack (with help from Yamamoto-san).
 * We received the real BS optic and gluing tools, and glued the disks and rods into the modified magnet jigs. We also tried the re-made secondary prisms in the gluing jigs and made shims to hold them more securely.
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 and Hirata-san):
 * Hirata-san shipped the optic and gluing tools to Kamioka.
 * Hirata-san did drawings and RFQs for IM/BF/SF ballast masses
 * Fabian worked on the SRx assembly frame.
Line 35: Line 22:
==== Plan for coming weeks ====
For more detail, see [[KAGRA/Subgroups/VIS/TypeB/ToDo]].		 ==== Plan for week of 7/18 ====
Full team at Kamioka from Tue-Fri, except Hirata-san (Tue-Wed only).
 * Glue prisms/magnets on BS.
 * Dismantle suspension.
 * Finish setting up filter service area (mostly already done by Mirapro).
 * Move BF to filter service area.
Line 38: Line 29:
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 7/24 ====
Full team at Kamioka from Mon-Fri, except Hirata-san (Tue-Fri) and Enzo (vacation).
 * Recheck alignment of assembly frame and centering of optical table.
 * Install IM, suspend BS and RM.
Line 46: Line 34:
    Vacation Info:
Hirata-san: Thu 7/20 through Mon 7/24
Enzo: Sat 7/22 through Sun 8/6
Fabian: Fri 8/4 through Mon 8/21
Mark: TBD Mid-Oct

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Past week report

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

  • We experimented with rearranging the arc weights to accommodate the magic wands and came up with a suitable scheme.
  • We used spare arc weights as extra ballast on the LBB to get it to float, and measured the height for a known load.
  • We put the blocks back under the LBB and unhooked it.
  • We moved the suspension from the tank back to the assembly frame.
  • We craned the LBB rings down onto the LBB but did not remove them yet. (This however is the last crane work in the tank until reinstallation, so the lid does not have to come off again and the pallet can be used for the PI.)
  • We put the crossbars back in the assembly frame underneath the SF and BF (and corrected an error in the height of the BF ones).
  • Enzo started setting up the SR3 rack (with help from Yamamoto-san).
  • We received the real BS optic and gluing tools, and glued the disks and rods into the modified magnet jigs. We also tried the re-made secondary prisms in the gluing jigs and made shims to hold them more securely.

At Mitaka (Fabian and Hirata-san):

  • Hirata-san shipped the optic and gluing tools to Kamioka.
  • Hirata-san did drawings and RFQs for IM/BF/SF ballast masses
  • Fabian worked on the SRx assembly frame.

Plan for week of 7/18

Full team at Kamioka from Tue-Fri, except Hirata-san (Tue-Wed only).

  • Glue prisms/magnets on BS.
  • Dismantle suspension.
  • Finish setting up filter service area (mostly already done by Mirapro).
  • Move BF to filter service area.

Plan for week of 7/24

Full team at Kamioka from Mon-Fri, except Hirata-san (Tue-Fri) and Enzo (vacation).

  • Recheck alignment of assembly frame and centering of optical table.
  • Install IM, suspend BS and RM.

Vacation Info: Hirata-san: Thu 7/20 through Mon 7/24 Enzo: Sat 7/22 through Sun 8/6 Fabian: Fri 8/4 through Mon 8/21 Mark: TBD Mid-Oct

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