Kozakai, (remote Shoda), T. Yamamoto, Enomoto, Akutsu

This is to confirm zpk parameters of the designed filters for MICH and PRCL feed forwarding to be input into the actual real time model. We succeeded to show what will happen if we actually implement the filters into the real-time model. For MICH, the artifically injected noise into the interferometer and the subtraction are shown in Fig .1, while Fig 2 shows the quiet time. The same for Fig 3 and 4, respectively, for PRCL. Note that the vertical axis are roughly calibrated to displacement noise (n/rtHz) but my calibration ignored (1+G) so don't believe the spectra shapes lower than ~100 Hz. The important thing is that (1) the artificially injected noise can be subtracted, and (2) it is promising for MICH that the filter would subtract actual noise.

Files: Dropbox/Personal/Akutsu/04_KamiokaWS/20200210/Offline ,

where the matlab *.m files in the directories MICH_FF and PRCL_FF were used to make the attached figures.

MICH

• From: K1:LSC-MICH_OUT_DQ
• To: K1:LSC-DARM_IN1_DQ

PRCL

• From: K1:LSC-PRCL_OUT_DQ
• To: K1:LSC-DARM_IN1_DQ

The transfer functinos from MICH to DARM and PRCL to DARM during the PRFPMI+OMC lock were newly measured today, and we used them. Kozakai-san did fitting of the measured transfer functions to foton zpk parameters with python scripts using IIRrational. See the files in /users/.ckozakai/KashiwaAnalysis/analysis/code/NoiseSubtraction

Then we implemented the promising MICH feed forward filter into the digital model. The detail will be reported later.