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Entry  Thu Nov 17 15:17:16 2016, gautam, Update, IMC, MCL Feedback MCLerror.pdfMCLtest.pngYarmCtrl.pdf
    Reply  Wed Nov 23 01:13:02 2016, gautam, Update, IMC, MCL Feedback MCL_plant.pdfOLG.pdfMC_armSpectra_X.pdfMC_armSpectra_Y.pdf
       Reply  Wed Nov 23 15:08:56 2016, rana, Update, IMC, MCL Feedback 
          Reply  Fri Feb 3 00:36:52 2017, gautam, Update, IMC, MCL Feedback - framing the problem 
             Reply  Fri Feb 3 11:40:09 2017, rana, Update, IMC, MCL Feedback - framing the problem 
                Reply  Mon Feb 6 17:03:41 2017, gautam, Update, IMC, MCL Feedback - simulink model updated mc40_v1.pdf
                   Reply  Mon Feb 6 18:20:08 2017, Koji, Update, IMC, MCL Feedback - simulink model updated 
                      Reply  Wed Feb 8 19:13:02 2017, gautam, Update, IMC, MCL Feedback - TF measurements 
                         Reply  Thu Feb 9 23:35:34 2017, gautam, Update, IMC, MCL Feedback - TF measurements mc40_v1.pdfCMboard_OLTF_fit.pdfFSSFast_OLTF_fit.pdfPCdrive_OLTF_measured.pdfdata.zip
Message ID: 12805     Entry time: Mon Feb 6 18:20:08 2017     In reply to: 12804     Reply to this: 12812
Author: Koji 
Type: Update 
Category: IMC 
Subject: MCL Feedback - simulink model updated 

It is more accurate to model the physical frequency noises at various places.

cf. See also 40m ALS paper or Shigeo Nagano PDH thesis on https://wiki-40m.ligo.caltech.edu/40m_Library

- The output 4 should be "Laser frequency"

- Seismic path should be excluded from the summing node

- The output after the PMC: "Laser frequency after the PMC"

- "Laser frequency after the PMC" is compared (diffed) with the output 1 "mirror motion in Hz"

- The comparator output goes to the cav pole, the PD, and the PDH gain: This is the output named "PDH Error"

- Tap a new path from "Laser frequency after the PMC" and multiply with the cav pole (C_IMC)
- Tap a new path from "Mirror motion" and multiply with the cavity high pass  (s C_IMC/omega)
- Add these two: This is the output named "Frequency noise transmitted by IMC"

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