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• VISMinutes20170526

Agenda/Minutes of the VIS Meeting on 2017/5/26

2017/5/26 13:30 - 15:00

Participants: Hirata, Takahashi, Okutomi, Iszhizaki, Tanaka, Mark, Aso, Fabian, Sato, Shoda, Ohishi, Enzo, Akutsu, Raffaele

Progress report

Schedule Chart : (PDF,MPP)

• Type-A: Finish Y-End in 3 weeks (by June 16). 8 weeks delay on the start of X-End installation from the original plan.
• Type-B: Start the installation into the chamber in the week of June 5th. 6 weeks delay
• Type-Bp: Schedule depends on when the PR2 flags will be removed. Roughly 3 weeks delay.

Type-A (Takahashi)

Installation in Y-end:

22nd(Mon)

• Dismounted the DP from the EQ stop.
• Disassembled the stat bolt from the DP.

23rd(Tue)

• Cut the stat bolt by 15mm.
• Mounted the DP. The height of the DP was increased by 5mm.
• Checked the DP weight.

24th(Wed)

• Closed the cap for BF.
• Lifted up the EQ stop, and disassembled the top plate.
• Lifted up the F1, and set the F1 at the higher position.

25th(Thu)

• Lifted up the F2 stage to the frame lock.
• Extracted the 3.3m wire from the cryostat.
• Assembled the top plate.
• Mounted the bridge frame on the hoot hold.
• Mounted the PI on the bridge frame.
• Suspended the filter chain from the TF.

Plan for coming weeks

• Tune the TF.
• Assemble the SF damper.
• Cable between the F1 and the TF.
• Lift down the top plate to the frame lock.
• Set the PI in the chamber.

Type B (Mark)

Past week report

At Kamioka (Mark, Fabian, Enzo, Hirata-san):

• 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.
• Swapped in three new LPCDs with fix for watchdog issue reported by Kamiizumi-san.
• 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 coming weeks

For more detail, see KAGRA/Subgroups/VIS/TypeB/ToDo.

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.

Type-Bp (Shoda)

Past week report

• We installed PR3 into the chamber.
  • After checking the balance and performance of the suspension roughly, we fixed everything and cleaned the suspension by wiping and blowing.
  • Set the optical bench intermediate ring and damper ring.
  • The whole suspension was installed into the chamber safely.
  • The optical bench is almost suspended. Note that the optical is still sitting on the chamber, since we still have some task remained which we have to sit on the optical bench.
  • Cabling is on going.
• We do not have news that the flags are removed completely yet.

Plan for coming weeks

• Cabling
• Performance check.
• Cleaning the PR3 clean booth and move to PR2 area.

IMMT (Ohishi)

Past week report

• Working on retrofit of magnet fixture jig of IMMT mirror.

  • Mirror spec

  • MC(D: 96mm, t at max 29.5mm)->IMMT(D: 99.8mm, t at max 51.8mm, 53mm)

Plan for coming weeks

• Finalize the design and order.

Watchdog system (Tanaka)

Past week report

• Creation of extended I/O PCB(plot type (With the Main 4ch WDS box and I/O box,I/O board For relay).

• Modification and update of document accompanying circuit modification.PDF(JGW-E1706772)

Plan for coming weeks

• Creation of extended I/O PCB(plot type (With the Main 4ch WDS box and I/O box,I/O board For relay).-->Ongoing.

Safety

• Incidents:
  • PR3 clean bag frame broke. Need a stronger one. Aso will check it in the next week.
  • There are several anchor bolts sticking out from the floor in the BS clean booth, imposing a tumbling hazard.
    • Put caution tapes to illuminate them
    • Will move a table back to cover those bolts.
• Notes
  • We need to bring crane licenses with us when operating a crane. Do not leave them at home.
  • BS team wants to use the shield safety blocks. Ishizaki-san will move them from PR to BS on Monday afternoon. 2 of them should be installed near the BS. 1 will be used near the PR2.
• Foreseen risks
  • Type-A: Crane works.
  • Type-B: Tricky works for cabling
  • Type-Bp: No heavy work expected.

Discussion

• How to divide the 3.3m long rod ?
  • Got a Virgo design. They use nail heads to join two rods together. We do not have nail heads.
  • Making a neck to create a nail head will add an extra bending point in the long rod: not desirable.
  • What we can do is make threads (M6) on the divided rods and join them together with a long nut.
  • Takahashi will check if this will have enough strength or not.

Travel Plans

• Travel (Week of 5/29):
  • Takahashi: 30 - 6/2
  • Shoda: 29 - 6/2
  • Mark: 29 - 6/2
  • Fabian: 29 - 6/2
  • Okutomi: 29 - 6/2
  • Fujii:
  • Ishizaki: 29 - 6/2
  • Hirata: 29 - 6/2
  • Sato: 29 - 6/2
  • Enzo: 29 - 6/2
  • Ohishi:
  • Tanaka:
  • Akiyama(Hosei): 30 - 6/2
• Travel (Week of 6/5):
  • Takahashi: 6-9
  • Shoda: 6-9
  • Mark: 6-9
  • Fabian: 6-9
  • Okutomi: 6-9
  • Fujii:
  • Ishizaki: 6-9
  • Hirata: 6-9
  • Sato: 6-9
  • Enzo: 6-9
  • Ohishi:
  • Tanaka:
  • Akiyama(Hosei): 6-9
  • Hashimoto(Hosei): 5-9

Next meeting

On 2017/6/2(Fri)