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.

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

• VAC: No issues were found.
• CRY cooler: Temperature of EX 50_REFBRT went down by 6K between 6/29 16:00 and 6/30 10:00. No other movement.
• Compressor: No issues were found.

IFO was used by CAL group during the day.
After their works, the state was set to be CALIB NOT READY. 

[Dan, Hido, Sawada, Yamamoto, Ushiba]

Abstract:

Gain tuning of MICH2DARM, MICH2PRCL, and PRCL2DARM FF were performed.
All update seems fine.

Detail:

First, calibration team measured the actuator efficiency ratio of MICH2PRCL/PRM2PRCL.
The new value was 0.03675 and FM10 of LSC_MICHFF2 filter bank was updated.
Figure 1 and 2 show the filters before and after the update, respectively.

Then, I measured MICH2DARM coupling with several FF gain to tune the MICH2DARM FF gain (fig3).
MICH FF performance seems better when MICH FF gain is 0.98, so I implemented the gain of 0.98 at FM10 of LSC_MICHFF1 filter bank.
Figure4 and 5 show the filters before and after the update, respectively

After that, I measured PRCL2DARM coupling with several FF gain (fig6).
Though the low frequency performance is worse than before, the best gain seems 0.8, so I update FM1 of LSC_PRCLFF1 filter bank.
Figure 7 and 8 show the filters before and after the update, respectively.
For further tuning of PRCL2DARM FF, we may need to modify the filter shape and it takes a time, so I didn't performit today.
Since current PRCL2DARM noise budget cased on the today's measurement is low enough (fig9), the current situation should be fine.

Since all updates are done by overwriting current FF filters, no SDF change happens.

5 days have passed since the last recovery. No problem has happened until now. So, the heat up inside the 19-inch rack could be the reason.