Differences between revisions 146 and 225 (spanning 79 versions)
⇤ ← Revision 146 as of 2017-05-26 10:54:56 →
Size: 3286
Editor: MarkBarton
Comment:
← Revision 225 as of 2018-02-02 10:26:31 → ⇥
Size: 2000
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):		 ==== 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 (klog [[http://klog.icrr.u-tokyo.ac.jp/osl/?r=4073|4073]]).
 * 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 placed the second order for payload parts, and an order for remachining of nuts for cable clamps on rods.
 * Fabian measured the gain of the ADC system (homework from the Commissioning Workshop).
 
==== Plan for week of 2/5 ====
Enzo on vacation; all others at Kamioka.
 * Make in-air pico adapter cables.
 * Calibrate LVDT.
 * Test IM picos and BF yaw pico.
 * Test FR.
 * Install ballast mass in BF.
 * Build IRM around IM.
 * Cable/test/adjust IM OSEMs.
 * Time permitting, do TFs from IM OSEMs to themselves and to optical sensor.
Line 9: Line 28:
 * 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 2/13 ====
 * No work Monday (建国記念の日の振替休日)<<BR>>
 * Enzo on vacation
 * Hirata-san at Mitaka Tue, Wed (to receive and wash parts).
 * All others at Kamioka.
-
 * Lift BF/IM/IRM/RM/TM and check total mass and balance.
 * Test BF picos.
 *
Line 35: Line 38:
==== 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.

 
 		 ==== 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 (klog 4073).

  • 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 placed the second order for payload parts, and an order for remachining of nuts for cable clamps on rods.
  • Fabian measured the gain of the ADC system (homework from the Commissioning Workshop).

Plan for week of 2/5

Enzo on vacation; all others at Kamioka.

  • Make in-air pico adapter cables.
  • Calibrate LVDT.
  • Test IM picos and BF yaw pico.
  • Test FR.
  • Install ballast mass in BF.
  • 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 2/13

  • No work Monday (建国記念の日の振替休日)

  • Enzo on vacation
  • Hirata-san at Mitaka Tue, Wed (to receive and wash parts).
  • All others at Kamioka.

-

  • Lift BF/IM/IRM/RM/TM and check total mass and balance.
  • Test BF picos.

Vacation Info

  • Enzo 1/30-2/19 (at Mitaka 1/29, part of 1/30)
  • Kozu-kun 1/29-2/2

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