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Entry  Fri Oct 10 03:05:09 2014, ericq, Update, LSC, Which side of optical spring are we on? comparison.pdf
    Reply  Fri Oct 10 03:25:11 2014, Jenne, Update, LSC, Which side of optical spring are we on (simulation) 10x
    Reply  Mon Oct 13 12:01:28 2014, ericq, Update, LSC, Which side of optical spring are we on? AOInjection_SqrtInv_REFLDC.pngAOinjection_SqrtInv_REFLDC.xml.zip
       Reply  Mon Oct 13 21:20:56 2014, Jenne, Update, LSC, Which side of optical spring are we on? (No progress) 
          Reply  Mon Oct 13 21:59:47 2014, rana, Update, Computer Scripts / Programs, Which side of optical spring are we on? (No progress) 
             Reply  Tue Oct 14 17:38:31 2014, ericq, Update, Computer Scripts / Programs, Rossa and Allegra wiped, Ubuntu 12.04 installed 
                Reply  Tue Oct 14 23:44:42 2014, diego, Update, Computer Scripts / Programs, Rossa and Allegra wiped, Ubuntu 12.04 installed 
                   Reply  Wed Oct 15 17:18:10 2014, Jenne, Update, Computer Scripts / Programs, Dataviewer fix with Ubuntu 12.04 
          Reply  Wed Oct 15 02:58:03 2014, Jenne, Update, LSC, Which side of optical spring are we on?  PRFPMI_MC2injection_PosCARMoffset_REFLDC_TRX_response_14Oct2014_TRX.pdfPRFPMI_MC2injection_PosCARMoffset_REFLDC_TRX_response_14Oct2014_REFLDC.pdfPRFPMI_MC2injection_NegCARMoffset_REFLDC_TRX_response_14Oct2014_TRX.pdfPRFPMI_MC2injection_NegCARMoffset_REFLDC_TRX_response_14Oct2014_REFLDC.pdf
             Reply  Wed Oct 15 19:56:38 2014, Jenne, Update, LSC, Which side of optical spring are we on? Meas vs Model AntispringModel_NegOffsetMeas_comparison.pdfSpringModel_NegOffsetMeas_comparison.pdf
Message ID: 10598     Entry time: Mon Oct 13 12:01:28 2014     In reply to: 10594     Reply to this: 10603
Author: ericq 
Type: Update 
Category: LSC 
Subject: Which side of optical spring are we on? 

 I went back into the DQ channels to look at the TF from AO injection to REFLDC (which is easy to do with this kind of noise injection TF).  

AOInjection_SqrtInv_REFLDC.png

I fear that REFL does not seem to have as much phase under the resonance as we have modeled, lacking about 10-20 degrees. This could result from the zero in the REFL DC response that we've modeled at ~200ish Hz is actually higher. I'll look into what affects the frequency of that feature. 

It is, of course, possible, that this measurement doesn't properly cancel out the various digital effects, but the REFLDC phase curves do seem to settle to (+/-) 90 after the pole as expected. 

DTT XML file is attached. 

Attachment 2: AOinjection_SqrtInv_REFLDC.xml.zip  5.340 MB  Uploaded Mon Oct 13 13:02:11 2014
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