Agenda/Minutes

Zoom Meeting

CRY+VIS Interface Meeting

Date: 2021/6/25 13:00-

Participants:

Post O3 Upgrade portal

Schedule

IX: TF measurement of MN is on going.
IY: Rough alignment of TM was tried. The ballast weight on the PF is too small to take a ballance. Additional spring on the BF is necessary.
EX: Alignment for the green beam. The week of 7/5?
EY: Mirror cleaning in Mitaka is on going.

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.

Discussion

VIS Meeting

14:00-

Participants:

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.

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 the asymmetry.

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)