Virgo Logbook

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Detector Characterisation (Spectral lines)

fiori, paoletti - 16:01 Monday 19 August 2019 (46708)

Acoustic injections WEB

This morning we injected broadband acoustic noise at WEB with the prepared setup. We managed to excite some structures and lines, some of which exist in the Quiet Hrec: Figure 1 (high resolution FFT), Figure 2 (spectrogram)

41.3 Hz
48.0 Hz ... and sometiing else closeby? (Figure 3.)
51.0
52.9
60.0
70.3, Figure 4.
bump around 106Hz (not in quiet Hrec), Figure 5.

Attached is log file with all details of injection times. A good time for analysis is 8 minutes starting at 12:22 UTC.

Interesting to check SWEB signals. Also, interesting to do the same at NEB.

Images attached to this report

46708_1566223267_WEB acoustic_106Hz_bump.jpg

Non-image files attached to this report

log_injections_August19_2019.txt

Comments to this report:

ruggi - 16:53 Monday 19 August 2019 (46711)

An investigation about the peak at 48.05 Hz was performed some months ago, injecting vertical noise on the payloads, because the vertical resonance of F7crossbar/Marionette was expected around that frequency. No vertical resonance was found exactly at 48.05 Hz, but the injection on WE payload had the effect to excite the 48.05 (beside the known vertical resonance, at 48.38 Hz).

The acoustic injection reported here has increased a lot the correction on the payload and F7, due to the local sensor which got noisier.

A more accurate shaking of WE payload can be performed, in order to see if something more clear come out.