Differences between revisions 298 and 299
Revision 298 as of 2018-06-22 13:35:18
Size: 3497
Editor: MarkBarton
Comment:
Revision 299 as of 2018-06-29 11:15:08
Size: 2665
Editor: MarkBarton
Comment:
Deletions are marked like this. Additions are marked like this.
Line 7: Line 7:
 * Mark checked the health of the suspensions after an earthquake on Monday morning. The BS watchdog tripped and there was a few µrad change in the pointing, but otherwise it was fine. SR3 and SR2 were also fine.
 * Mark, Enzo and Terrence finalized the trim mass on the BF to set the SF keystone height and BF pitch/roll.
 * They weighed the SF/... section. With no internal trim mass in the SF but with the flying saucer and rod, but with 2 Promec masses for rough balance, it was 255.4 kg, so allowing 1 kg for cables and fine trim mass, we would like a PI load capacity of 256.4 kg.
 * Enzo and Terrence cabled and tested the SF fishing rod, and reversed the connections on the SF LVDT actuation to bring it to standard polarity.
 * Mark and Enzo made many improvements to the Type B MEDM screens.
 * Enzo and Mark measured the BF and SF bounce frequencies (with the other keystone locked).
 * Enzo replaced a HPCD that seemed to have failed during the bounce test (but had just had a watchdog trip), and then replaced the replacement, which really did fail. It turns out we need to avoid applying more than about 25000 counts of GAS actuation.
 * Enzo offloaded the BF LVDT actuator with the BF FR to remove the need for a 10000 ct offset.
 * Hirata-san and Kozu-kun struggled to tune the top filter for SR3 - see klogs 5310, 5324, 5337, xxxx. At first the results were somewhat unrepeatable, with high frequency and low load capacity. This was improved by using a torque wrench (set to 50 N.m) to tighten the blade base clamp screws, retightening the blade tip screws (which had worked loose) and tightening the collar on the end of the shaft of the magic wand. Eventually we decided on a compression of 30 mm, which should give a frequency of around 0.5 Hz if we remove one Cu damper segment from the SF. Hirata-san applied the 30 mm compression but we skipped another round of testing with the dummy load and will go straight to hanging the SF/... section on the assembly frame.
 * We wrapped PI #1 (for SR2) and craned it from behind SR3 to behind SRM. We can now wrap PI #3 (for SR3) and crane it straight to the assembly frame.
 
==== Plan for week of 6/25 ====
 * Mark, Enzo, Hirata-san, Terrence at Kamioka Mon-Fri.
 * Kozu-kun at Kamioka except Thu.
 * --
 * Shutdown Type B controls (as far as possible) in preparation for risk of accidental power outage during electrical work on 6/26.
 * Prepare SF damper magnet ring and rods.
 * Install PI #3 in SR3 AF.
 * Suspend SF/... section.
 * Lots of cable routing and testing.
 * Move PI #1 (for SR2) over SRM tank to work area, install blades and tune.
 * We powered down the Type B racks as a precaution against possible loss of power during work on Tuesday, and later powered them up again.
 * We put a flange cover over the hole in the floor near the filter tuning area as a temporary safety measure. We later managed to entirely close the part of the hole that was not covered by the filter, by moving the filter towards the outside and using short floor panels from SR2 on the tank side.
 * We removed the SR3 PI from the filter tuning area and brought in the SR2 one.
 * We put magnets on the SR damper magnet ring to match the two Cu segments we were using.
 * We craned the SR3 PI into the AF, connected it to the security structure, and hooked the SF/... section and the SF damper magnet ring.
 * At first the F0 did not rise, and we realized that we had 2 kg less margin than we originally thought because we had not allowed for the PI-SF rod receptacle, the top disk which holds the yaw stepper mechanism, or the stepper itself.
 * However we were able to try the redesigned PI fishing rod, parts for which had just arrived. The optional strong CuBe spring in the new arrangement gave plenty of extra lift, so that we now have about 5 kg of margin. We did have to move the yoke to work around the problem that the CuBe spring tends to tilt the keystone, but we got it moving freely. We will also have to compress the blades some more to compensate for the extra stiffness, which caused the frequency to rise from 0.5 Hz to 0.9 Hz.
Line 33: Line 20:
 * --
 * Continued tuning of filter in PI #3 for SR3.
 * Building and tuning of filter in PI #1 for SR2 (time permitting).
 * Lots of cable routing and testing.
 * Install geophones and arc weights.

==== Plan for week of 7/9 ====
 * Mark, Enzo, Hirata-san, Kozu-kun, Terrence at Kamioka Mon-Fri.

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

Type B (Mark)

Report for week of 6/18

  • We powered down the Type B racks as a precaution against possible loss of power during work on Tuesday, and later powered them up again.
  • We put a flange cover over the hole in the floor near the filter tuning area as a temporary safety measure. We later managed to entirely close the part of the hole that was not covered by the filter, by moving the filter towards the outside and using short floor panels from SR2 on the tank side.
  • We removed the SR3 PI from the filter tuning area and brought in the SR2 one.
  • We put magnets on the SR damper magnet ring to match the two Cu segments we were using.
  • We craned the SR3 PI into the AF, connected it to the security structure, and hooked the SF/... section and the SF damper magnet ring.
  • At first the F0 did not rise, and we realized that we had 2 kg less margin than we originally thought because we had not allowed for the PI-SF rod receptacle, the top disk which holds the yaw stepper mechanism, or the stepper itself.
  • However we were able to try the redesigned PI fishing rod, parts for which had just arrived. The optional strong CuBe spring in the new arrangement gave plenty of extra lift, so that we now have about 5 kg of margin. We did have to move the yoke to work around the problem that the CuBe spring tends to tilt the keystone, but we got it moving freely. We will also have to compress the blades some more to compensate for the extra stiffness, which caused the frequency to rise from 0.5 Hz to 0.9 Hz.

Plan for week of 7/2

  • Mark, Hirata-san, Terrence at Kamioka Mon-Fri.
  • Enzo at Kamioka Mon-Wed.
  • Kozu-kun at Kamioka except Wed.
  • --
  • Continued tuning of filter in PI #3 for SR3.
  • Building and tuning of filter in PI #1 for SR2 (time permitting).
  • Lots of cable routing and testing.
  • Install geophones and arc weights.

Plan for week of 7/9

  • Mark, Enzo, Hirata-san, Kozu-kun, Terrence at Kamioka Mon-Fri.
  • --
  • Lock suspension.
  • Remove tank lid and raise LBB damper rings.
  • Crane suspension into tank.

To-Do Lists, Schedule

Vacation Info

  • Kozu-kun: 7/4 Tokyo.
  • Enzo: 7/5-6 NAOJ Party, Mitaka.
  • Terrence: 8/24-26 f2f, then returns to Hong Kong.
  • Enzo: 9/14 JPS, 9/15 through 10/18 vacation in Chile.

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-06-24 12:23:36 by fabian.arellano)