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CAL (General)
Shingo Hido - 18:38 Friday 13 June 2025 (34088) Print this report
Weekly calibration on 0613

CAL group

We did the calibration measurements.

Estimated parameters in the Pre-maintenance measurements are as follows.
 H_etmxtm = 3.87957055e-14 @10Hz ( 0.03% from previous measurements)
 H_etmxim = 1.60823003e-14 @10Hz  ( 1.16% from previous measurements)
 Optical_gain = 2.128193e12               ( -2.87% from previous measurements)
 Cavity_pole = 18.349842 H                ( 1.67% from previous measurements)

Previous values are listed in klog#34090.

Fig. 2 shows the ratio of the sensing functions estimated on June 13st and June 6th.
As can be seen from this figure, the actual difference in the sensing function is approximately -1.2%.

Estimated parameters in the Post-maintenance measurements are as follows.
 H_etmxtm = 3.893062476e-14 @10Hz ( 0.03% from pre-maintenance measurements)
 H_etmxim = 1.552203891e-14 @10Hz ( -3.4% from pre-maintenance measurements)
 Optical_gain = 2.1602595e12              ( 1.5% from pre-maintenance measurements)
 Cavity_pole = 17.97637634 Hz            ( -2% from pre-maintenance measurements)

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takahiro.yamamoto - 19:41 Friday 13 June 2025 (34222) Print this report

After the update of calibration updates, we raised CFC_LATCH and IFO guardian moved from CALIB_NOT_READY to READY.

All detected changes are coming from the planned commissioning activities.
- Chagens in foton Fig.1 are related to the update of optical gain and actuator efficiencies (klog#34088).
- Changes in guardian shown in Fig.2 are related to klog#34199 (PCAL_s), and klog#34182 (ARM).
- Changes in SDF tables shown in Fig.3-5 are related to klog#34221 (k1calcs), klog#34190 (k1asc1), klog#34205 (k1ascbpc), klog#34198 (k1psliss), klog#34202 (k1pemmcf0), klog#34169 (k1calex), klog#34219 (k1calex, k1caley), and klog#34209 (k1sdfmanage),
- No changes in the model (Fig.6).

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Shingo Hido - 8:27 Sunday 15 June 2025 (34227) Print this report

During the measurement of the transfer function from ETMXTM to DARM (0613/1601_*xml), it was found that the signal was saturating at "OMC_TRANS_DC_{A, B}_IN1" (Fig. 1). Since this issue began occurring right after klog#33944, it is believed to be caused by a slight gain increase resulting from the modification to ETMX_TM_COILOUTF_HP_H{1, 2, 3, 4}.


As a countermeasure, the excitation amplitudes at the following frequencies in the template were reduced from 10 to 7:
[33.4757308959961, 35.9416084289551, 37.2418098449707, 46.5193901062012, 47.1052284240723, 49.2812309265137]


In the subsequent measurements used for parameter estimation (0613/1707_*xml), it was confirmed that there was no saturation (Fig. 2).

By taking the ratio of the sensing function model (Fig. 3), it was confirmed that the presence or absence of saturation had little impact on the parameter estimation.

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