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• VISMinutes20210625

Agenda/Minutes

Zoom Meeting

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CRY+VIS Interface Meeting

Date: 2021/6/25 13:00-13:55

Participants: Takahashi, Hirata, Miyo, Kimura, Yokozawa, Ikeda, Node, Ushiba, Tomaru, Aso

Post O3 Upgrade portal

Schedule

• IX: MN was recovered. TF will be measured precisely in the next week.
• IY: Rough alignment of TM was tried. The ballast weight on the PF is too small to take a balance. Additional spring will be implemented on the BF on 7/28. Adjustment of ballast on the PF was scheduled on 7/29.
• EX: Alignment for the green beam is planed in the week of 7/5. OL damp in PR3, Yaw damp, and Oplev are necessary.
• EY: Mirror cleaning in Mitaka is on going. Though 24h x2 cleaning was applied, the stain remains. Still continue through the week end. Splay type FC will be tried.

Status

• Corrugate tube fixing jig: Delivery and implement are scheduled on 7/12-13.
• TM height setting: Next target is ITMY.
• Commissioning in air: X-arm.
• Commissioning in vacuum:
• Overall commissioning:
• Acceptance check: Group work is set every Friday.
• PF actuator: After SC.
• Jig for FC painting:
• Separation of rack in 2F: On the maintenance days in July.
• Disassembly of PRM/PR2 assembly frame: This is scheduled on 6/28-29.
• New vacuum pumps for V-chambers: Check the port location and interference of cabling.
• Extension of cables for picomotor drivers: Test was planed in EYV.

Discussion

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VIS Meeting

14:00-14:55

Participants: Takahashi, Hirata, Miyo, Sato, Fabian, Sugiyama, Aso, Terrence, Tanaka, Ishizaki

Klog

This is generated by python script in /users/Miyo/dropbox/Script/scrapping/main.py.

Summary Report

Type-A

• Assembled six accelerometers for IY and EX. The original capacitance sensors were replaced to the LVTDs.
• Designing the adapter plate for H4 geophones and the protection cover for accelerometers.

Type-B

I wrote the Type-B section of the O3GK paper.

BS

• With Takahashi-san we moved the ballast masses on the IP to have a more uniform distribution with the hope of reducing the asymmetry in the IP-L and IP-T resonance frequencies. It did not work. On the contrary, the difference increased: it went from 24 to about 30 mHz.
• Then we added 4.7 kg and the frequencies went down to 63 and 92 mHz.
• The temperature was 23.8 degrees, which is high. The frequencies will decrease when it becomes 23 degrees again.
• L and T look strongly coupled. Maybe similar to what Terrence observed in SRM.

SR2

We measured the IP transfer functions.

• The resonance frequencies in L and T are both close to 70 mHz.
• They cannot be distinguished from each other but they below 80 mHz.
• From measurements made this morning, the three legs seem equally stiff.

SR3

• The IP resonance frequencies in L and T had an asymmetry of about 23 mHz and one of them was very low: 70 and 47 mHz in L and T respectively.
• We removed 1.1 kg and redristributed 3.8 kg: the frequencies became 78 and 55 mHz.
• Later we removed 1.2 kg and they changed to 83 and 63 mHz.
• We were not able to remove or decrease the asymmetry.
• From measurements made this morning, it seems that the IP-H1 leg is stiffer than the others.

SRM [Terrence]

• I have modeled the LVDT and geophone sensor noises. These will be useful for designing sensor correction filter, blending filters, and damping filters. Results here.

• I have also inter-calibrated the geophones with the LVDTs. Not posted yet. Will post after getting the geophone sensing matrix.
• I attempted to align the Geophones to the LVDTs but I have difficulties:
  • I aligned the actuators to the LVDTs at 1 Hz, and tried to align the geophones to the actuators at 1 Hz. This way we can align the LVDTs and the geophones.
  • But the geophones have a strange phase response at 1 Hz. This is probably due to poor calibration filter, but I am inclined not to fix this now.
  • I am trying a different frequency, i.e. 0.2 Hz.
• The optical lever will become important soon. But the signals were zeroed out. Is it installed?

Remaining tasks

• Install the supporting beams of the BS outer frame.
• In BS, SR2 and SR3 lock the IP and F0 to measure noise.
• Measure parameters for the acceptance check.

Type-Bp

• The green laser reflected by SR3 reached the X End.
• No major ajustments to the payload were necessary.
• It only required adjustment in yaw, which was done with the BF Damper first and later offloaded to the traverser.
• This likely means we left the payload in good condition.

Type-C

Electronics

Control

Schedule

See Schedule

• Type-A team: Adjustement of IYV
• Type-B team: Remaining work

Milestone

• IMC suspensions are ready in air [40] will finish 2021/04/21.

• PRs are ready in air [643] will finish 2021/07/09.

• ETMX is ready in air [656] will finish 2021/08/25.

• ITMX is ready in air [657] will finish 2021/08/31.

• ETMY is ready in air [658] will finish 2021/09/16.

• ITMY is ready in air [659] will finish 2021/11/08.

• BS is ready in air [691] will finish 2021/11/24.

• SRs are ready in air [663] will finish 2021/12/20.

• Output suspensions are ready in air [695] will finish 2021/12/21.

• TMSY is ready in air [708] will finish 2021/??/??.

• TMSX is ready in air [684] will finish 2021/??/??.

2021/03/29 updated

Safety

Discussion

• Real-time model modification [Terrence]
  • Two requests (Of course LIGO doesn't have them)
    • Sensor correction path for the optical levers, this allows us to estimate the control performance without the interferometer. The seismometer signal exists in the model, I see no reason why we don't include that path.
    • There's LVDTALIGN for aligning the LVDTs, which is good. But then I just realized the screen for ACCALIGN exists but they are all white. Can we at least add this for aligning the geophones/accelerometers?

Travel Plans

The week from 6/28

• Takahashi: 6/28-7/2
• Sato: 6/28-7/2
• Hirata: 6/28-7/2
• Yano: 6/28-7/2

The week from 7/5

• Takahashi: 7/5-9 (KIW8 7/7-9)
• Sato: 7/5-9
• Hirata: 7/5-9
• Yano: 7/5-9

Next meeting

• 2021/7/2(FRI)