PDF showing each fitting: https://www.dropbox.com/scl/fi/h87b1kxmtvxrobqcc8f35/each_fit.pdf?rlkey=xtrz5wmwzb5t0a5zfgih8tmb0&st=579p0hzm&dl=0

Operators

Takaaki Yokozawa, Hiroshi Takaba, Dan Chen

Shift Time

9:00–17:00 JST

Check Items

• VAC: No issues were found.
• CRY cooler: No issues were found.
• Compressor: No issues were found.
• OBS INTENT: The OBS INTENT was ON throughout the shift.

Note

• Around 11:00 JST, ground motion increased. It returned to normal around 14:00 JST.
• Around 12:00 JST, the network connection was lost. It recovered around 12:30 JST.
• The following earthquakes occurred near the Tokara Islands:
  • 14:51 JST – Magnitude 5.1
  • 14:59 JST – Magnitude 5.2
  • 15:07 JST – Magnitude 5.1
  • 15:26 JST – Magnitude 5.6

We analyzed the violin mode peaks using approximately 6000 seconds of data starting from GPS time 1433982518 (2025-06-15).

• For the 1st, 2nd, and 3rd violin mode frequency regions, peaks were searched and fitted individually. The fitting results are attached.

• During visual inspection of the fitting results, obviously incorrect fittings were marked with “X.”

• Most of the fitted peaks show Q factors around 1e5. In the 1st mode region, there are three peaks with significantly higher Q values (they look too high...), which are currently under investigation.

• The mirror temperatures at the time of measurement were as follows:

  • Temperature [K]: (IX, EX, IY, EY) = (92, 49, 42, 58)

• A PDF showing each fitting result is also attached.

I just compared BNS and IRXY trans Norm for the recent 22 days as Fig.1

• A very long decreasing trend can be recognized in IRXY_NORM. However, it could be recovered by some adjustments as -19 days, -8 days, and -6 days.
• The BNS reduction around -7 days seems to correlate with the IRXY trans reduction.

Do you find any more characteristic points?

N2 increased and decreased as Fig.1

Plot with "K1:CRY-TEMPERATURE_IX_4K_REF2_4K_HEAD".

With Shingo Hido

K1:VAC-PRESSURE_X_00 is going up.

Operators name: Takaaki Yokozawa, Hiroshi Takaba, Dan Chen
Shift time: 9-17 (JST)
Check Items:

• VAC: No issues were found.
• CRY cooler: No issues were found.
• Compressor: No issues were found.

IFO was used by CAL group during the day.
After a meeting between Miyoki-san, Ushiba-san, Sawada-san and CAL group, the state is planned to be set to OBSERVING.

Finally, I raised CFC_LATCH bit and moved from CALIB_NOT_READY to READY.

Differences in foton filters shown in Fig.1 are related to klog#34424 (K1:CAL-CS_DARM_*) and klog#34425 (K1:CAL-CS_SUM_{MICH,PRCL}_*).
Differences in SDF tables shown in Fig.2 are related to klog#34411 (K1:CAL-MEAS_*) and klog#34426 (K1:CAL-CS_TDEP_*).
There is no change in guardian code and model files as shown in Fig.3 and Fig.4, respectively.

K1CALCS

Channels in JGW-L2314962

It's related to klog#34425.
They were updated based on the latest value of optical gain of DARM and ETMX actuator efficiencies in klog#34424.

Changes were accepted on observation.snap (Fig.1), down.snap (Fig.2), and safe.snap (Fig.3).
Finally, numerical rounding errors were reverted after re-loading observation.snap as shown in Fig.4.

MICH and PRCL calibrations were updated by using the values in klog#34423 as follows.
- 1/H_MICH [K1:CAL-CS_SUM_MICH_ERR_FM1]
- A_BS(1) [K1:CAL-CS_SUM_MICH_BS_TM_FM1]
- 1/H_PRCL [K1:CAL-CS_SUM_PRCL_ERR_FM1]
- A_PRM [K1:CAL-CS_SUM_PRCL_PRM_TM_FM1]
Actual changes were shown in Fig.1.

After then line tracking parameters were also updated based on the DARM calibration parameters in klog#34424.
Updated EPICS records can be found in JGW-L2314962.
They were accepted on {observation,down,safe}.snap in klog#34426.

I estimated and updated the parameters related DARM (Fig.1).
There is no strange variations (Fig2).

 H_etmxtm = 3.839154366e-14 at 10Hz (0.23% from previous measurements)
 H_etmxim  = 1.535938431e-14 at 10Hz (-1.9% from previous measurements)
 Optical_gain = 2.129473235e12 (0.07% from previous measurements)
 Cavity_pole = 18.127587391 Hz (-0.76% from previous measurements)

Previous parameters are listed in klog#34393.

I investigated the variation in optical gain (specifically, the gain of the sensing function) between 0602 full calibration (klog#34033) and 0630 full calibration (Fig.3).
A decreasing trend was observed from the measurement date (June 2) toward June 20, followed by an increase thereafter.
Since a continuous change can be observed on this time scale (although further data accumulation is needed),
there is a possibility that calibration lines could not only account for statistical fluctuations, but also help suppress systematic errors by correcting for actual variations.

In last night, I reduced the voltage to heaters for IY and EX IM by ~ 0.3V to reduce the temperature.

Fig.1 shows the relation between IM temperatures and BNS sensitivity. IY temp kept increasing by ~ 1K. On the other hand, the EX temp decreased by 1K.

Fig.2 shows a longer trend. It is difficult to find remarkable relations.

The best BNS sensitivity is 7.35Mpc just before the lock loss. We need calibration?

• Each value is estimated based on JGW-L2314903.
• Estimated values by Pcal and Free-swing are consistent with each other at approximately 3%.
• Previous full measurement which is the reference of comparison is klog#34033.
• There is no significant change in all parameters.
• Numbers in parentheses indicate a number of engaged de-whitening filters.
  • Low-frequency (<1Hz) zero/pole in disengaged de-whitening filters (see also klog#33874) are compensated based on circuit measurement only for ETMX in klog#34229 and klog#34244.
  • So this effect must be considered for other suspensions.

We accepted SDFs related to the cal measurement (klog#34412) in observation.snap, down.snap, and safe.snap (k1calcs).
K1:CAL-MEAS_{CURRENT, LATEST}

with Dan, YamaT, SawadaT

We performed full measurements for the IFO calibration.
The analysis results will be posted at a later date.

Notes:

The DARM-related measurements were conducted after adjusting the feedforward gains (see klog#34410).
Following the same method as klog#34040 and klog#34033, we performed measurements to observe the changes in DC caused by differences in the number of whitening filter stages for ITMX-TM and BS-TM.

Measurement files (`/users/CAL/current/measurements/2025/0603/0920_*`):
0920_BS_TM_PRCL.xml   : Whitening = 1 stage
0920_BS_TM_PRCL-1.xml  : Whitening = 0 stage
0920_ITMX_TM_DARM_PRFPMI_WFOFF.xml : Whitening = 0 stage
0920_ITMX_TM_DARM_PRFPMI_WFON.xml  : Whitening = 3 stages

Here is a update of the 8 blasting between 2025/06/18 03:22:49 UTC and 2025/06/26 13:59:52 UTC. The plots are available at DAC wiki.

• 6 times: lockloss occurred from OBSERVATION state
  • The the amplitude of the seismic motion was large enough to make the lockloss.
  • Even though the bomb size was 6.2 kg (which is relatively small), the lockloss occurred. I guess this is because the blasting point is approaching to the KGRA tunnel.
• 2 times: interferometer was in down state or during lock acquisition.