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CAL (General)

dan.chen - 17:01 Monday 19 May 2025 (33823)

ETMX High Power Coil Driver Transfer Function Measurement

With HidoS, YamaT, SawadaT

We performed the transfer function measurement of the high power coil driver for ETMX.

As noted in klog32925, this coil driver was replaced after the O4a observation run. Therefore, this measurement was necessary to characterize the new unit. However, it is still uncertain whether this coil driver will actually be used during the O4c observation run.

The measurement setup (equipment and cables) has been left in place, as it will be reused for the planned installation of the Low Power Coil Driver (LPCD) this week.

The ETMX suspension cabling has been restored to its original configuration. However, the signal split cable used during the measurement remains connected. We have confirmed that the test mass coil can work properly.

A more detailed report will be added later.

Comments to this report:

dan.chen - 8:56 Tuesday 20 May 2025 (33832)

Picture

Shingo Hido - 13:48 Tuesday 20 May 2025 (33835)

I performed a fitting analysis on the measured data. Figure 1 shows the measured data along with the fitted curve, and Figure 2 shows the residuals between them.
The figures below represent a subset of the results; the complete results have been uploaded to the wiki.
From the results, it was confirmed that there is no significant deviation between the model and the measurement in the 10 Hz to 10 kHz range.
When all three zero-pole stages are turned ON simultaneously, the measured values tend to fluctuate. Therefore, for high-precision measurements, it may be better to measure each stage individually.

Images attached to this comment