No, it was just the remaining work of the IMC chamber closing. It's independent of the vibration tests.

I measured the inductance and resistance of the MCi/MCo suspensions.

I measured the inductance and resistance of the MCi/MCo suspensions.

I checked the lightning information in the Blitzortung database.

Yesterday, 4 events were recorded, but all of them were after the blackout.

In the FALMA information, many lightnings were recorded around 8 am, but not around noon.
I heard a thunder at 13:44 yesterday.

Note:
Blitzortung uses VLF (~10 kHz) signals and identifies each stroke, for the worldwide scale (~4000 km)
FALMA uses LH (~100kHz) signals and distinguish sparks in a stroke, within Chuubu(中部) area.

I compared the recent results to the TAMA paper (Rev. Sci. Instrum. 73, 2428–2433 (2002)).
They are quite different...

I wonder whether our measurements and analysis are appropriate or not. 
It might be necessary to locate sensors both on a base and a table simultaneously.

I compared the MCF seismometer's signal between the old and the new places.

Red: New place (5/14 9 pm)
Blue: Old place (5/13 9 pm)

Z-axis: The new place is smaller
X/Y-axis: The new place is larger over 70 Hz and smaller below it. 

I compared the TF from Base acceleration -> Table acceleration between the OMC (5/15) and the IFI(5/2).

The result shows:

• Horizontal: the difference is not clear. (IFI is larger in the X-direction below 50Hz?)
  • note that the tapping direction is vertical.
• Vertical:
  • below 130Hz: IFI had a larger amplitude.
  • 130-180Hz: almost same
  • over 180Hz: OMC had a larger amplitude. (bad coherence at IFI)

[Takano, Washimi]

We performed a hammering test for the OMC stack (-X side), the same measurements and analysis as the IFI work (klog29482)
(See also the previous test, klog29310 )

• optical table -> optical table
• base plate -> optical table
• nothing -> optical table (as a reference)
• base plate -> base plate (2 sets)
• ground -> base plate (2 sets)

After this work, we moved the permanent seismometer (S1707526) from outside to inside the MCF clean booth.
At first, we tried to locate it below the MCF chamber (like OMC), but the height of the space was not enough.
Finally, the seismometer is located as the pictures place. (It needs to be moved if we re-open this chamber, maybe)

[YokozaWashimi]

For the IMC vibration tests for the resistance against blastings (~200 um/sec @ KAGRA CS is expected, JGW-G2415755), we checked how large ground vibration we can generate.

I (M~75kg) jumped near the MCF seismometer located outside of the clean booth. The peak amplitude was ~100 um/s in the Y&Z-directions and ~40 um/s in the X-direction.
During this work, the IMC cavity power was not changed.

I plotted the transfer functions from the impact hammer to the accelerometer, by selecting the single pulses and requesting the coherence >0.5. 
The results when the accelerometer was put on the ground were not good coherence and difficult to use.

I also evaluated the transfer functions from the Base vibration to the Table vibration, by

Thank you for the information.

At least this behavior was reported on April 1st this year (asked by Uchiyama-san via email), but I couldn't identify this at that time.
The SEM plot making is working with the pem38 conda environment, which has not changed in a long time (>2 years?)

I changed my script from using TimeSeries.read() to using TimeSeries.fetch(), to fix a problem on Feb.18 this year (klog28619).
I guess the reading started to apply slope=6.1028e-05 from this time. 

I checked the vacuum gauge data inconsistency between MEDM and the Slow monitoring page.

The value at "2024-05-13 09:00:00 JST" was "1.03747602e-09 Pa" in the frame file without any calculation, even the MEDM screen shows "1.7e-05 Pa".

Their ratio is "6.1028001176470595e-05", which number is very similar to the factor from an ADC count to Volt (6.1e-4 V/count).

For a temporal treatment, I correct this factor in the Slow monitoring page plots.

Same analysis for other measurements.

I'm updating the hammering test analysis.

Generally, one event should be a single pulse, and multiple pulse events due to bounding need to be removed from an analysis.

It can be realized by using a time-over-threshold (ToT) automatically. In this case, I request it be less than 0.02s.

After choosing single pulse events, the transfer functions became smooth and the coherence became larger.

Yesterday 9:45, Hayakawa-san stopped the Y2300 water pump.

[YokozaWashimi]

We took 4π photos inside the IFI, IMM, and PRM chambers.

https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=15766

I estimated the transfer function from the base plate vibration to the optical table vibration, by
TF(impact@base -> ACC@table) / TF(impact@base -> ACC@base)

I also did the same calculation for the Ground (z) ->Table case, but the results became over 1 for many frequencies. I need to investigate whether my analysis is correct or not...

[Komori, Tanaka, YokozaWashimi]

We performed the Hammering test for the IFI stack (+X, +Y side stack).

• optical table -> optical table
• top stack -> optical table
• middle stack -> optical table
• bottom stack -> optical table
• base plate -> optical table
• ground -> optical table
• nothing -> optical table (as a reference)
• base plate -> base plate
• ground (leg) -> base plate
• ground (leg) -> ground
• ground (concrete) -> ground

sorry, the legend was clipped.

It is same for all plots.

I plotted the high-resolution (3-hour data, 128s FFT) ASDs and Coherences for the geophones and ACCs on the OMC chamber, for the night time before vacuum breaking.

[YokozaWashimi]

We moved the 3-axial accelerometer and the impact hammer from the OMC area to the IFI area.

[YokozaWashimi, Ishikawa, Ozaki, Sudo]

We performed hammering tests (vertical tapping) for the OMC in-vac table.
The tapped points are the table, the base plate, and the ground near the stack1 or 2. 

The readout of the water fluid has recovered.

[YokozaWashimi, Tanaka, Ozaki, Sudo]

Today we tried to evaluate the seismic isolation of the OMC stacks, using a 3-axial accelerometer (S2315344) and an impact hammer (G1910656).
This is a quick report.

1. Locating the ACC on the OMC vac-table (Fig.1, Fig.2)
2. Tapping each stack (top, middle, bottom of stack1, stack2) with the impact hammer (direction: Fig.3)
3. Picking up each pulse (-0.2/+0.8 sec) and calibrating its transfer functions from impact [N] to acceleration [m/s2] automatically (example: Fig.4, Fig.5)
4. Calculating averages of the events (Fig.6, Fig.7)