Yamada-kun pointed out that above 70 Hz, there was no coherence in the past TFs from MN_PS_L vs DARM and for this reason the conclusion "ITMX MNL_PS control noise is limiting the sensitivity"  could be not correct.

To check if these loops are really limiting the sensitivity (above 100 Hz), today I measured again these TFs and estimated again these control noise contributions.

The attached plots show the results.

-In Pic1, Pic2,Pic3 Pic4, Pic5  the amplitude, the phase and the coherence are shown:

-above 100 Hz the coherence is high

- The TFs show same behavior (see Pic5) and can be fitted as 1/f^6

-Pic6 and Pic7 show the MN_PSL control noise projection for each TypeA suspension and the total contributions.

Looking at these plots seems MNL_PS control noise is not limiting the sensitivity above 100 Hz

Note

The measurements are saved in:

/kagra/Dropbox/Subsystems/VIS/Automeasurement/TypeA/ITMX/TF/Measurements/20200312

/kagra/Dropbox/Subsystems/VIS/Automeasurement/TypeA/ETMX/TF/Measurements/20200312

/kagra/Dropbox/Subsystems/VIS/Automeasurement/TypeA/ITMY/TF/Measurements/20200312

/kagra/Dropbox/Subsystems/VIS/Automeasurement/TypeA/ETMY/TF/Measurements/20200312