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Entry  Tue Feb 17 16:44:04 2015, Koji, Update, LSC, Delay line installed again 
    Reply  Tue Feb 17 19:49:51 2015, Koji, Update, LSC, Delay line un-installed again 
       Reply  Mon Feb 23 21:57:13 2015, Koji, Update, LSC, Delay line installed again (experiment, round 1) 
          Reply  Tue Feb 24 01:57:01 2015, Jenne, Update, LSC, Modelled effect of relative modulation phase ChangeInAngle_PRCLvsMICH.pngREFL33_MICH_SensMat_vsModulationOrder_vsModulationPhase.pngREFL33_SensMat_vsModulationPhase.pngREFL33_PRCL_nominalVsLoweredGamma.pngREFL33_MICH_nominalVsLoweredGamma.png
             Reply  Thu Feb 26 00:20:54 2015, ericq, Update, LSC, Modelled effect of relative modulation phase 33budget_canceled.png33budget_nominal.png2015-02-ModPhase.zip
                Reply  Thu Feb 26 01:51:39 2015, ericq, Update, LSC, Sideband HOMs C1_HOMcurves_PR.pngC1_HOMcurves_Y.pngC1_HOMcurves_X.pngC1_HOMlist.zip
                Reply  Thu Feb 26 01:53:35 2015, Koji, Update, LSC, Modelled effect of relative modulation phase 
       Reply  Tue Feb 24 23:39:16 2015, Jenne, Update, LSC, Delay line re-installed again 
          Reply  Wed Feb 25 04:59:47 2015, Jenne, Update, LSC, Delay line re-installed, measurements round 2 SensMat_PRMI_24Feb2015.pdf
             Reply  Wed Feb 25 12:16:27 2015, Koji, Update, LSC, Delay line re-installed, measurements round 2 
                Reply  Wed Feb 25 14:18:28 2015, rana, Update, LSC, Delay line re-installed, measurements round 2 
          Reply  Wed Feb 25 14:51:13 2015, Jenne, Update, LSC, Delay line un-installed again 
             Reply  Wed Feb 25 20:00:39 2015, Jenne, Update, LSC, Delay line un-installed again - sensing matrix comparisons 
                Reply  Wed Feb 25 23:48:57 2015, rana, Update, LSC, some thoughts 
                   Reply  Thu Feb 26 20:02:46 2015, Jenne, Update, LSC, re: some thoughts 
Message ID: 11074     Entry time: Thu Feb 26 01:53:35 2015     In reply to: 11072
Author: Koji 
Type: Update 
Category: LSC 
Subject: Modelled effect of relative modulation phase 

Ok... This is what I was afraid of, and it seems true.
i.e. the relation ship of the modulations for the 3f cancellation is making the PRCL signals cancel each other.

It agrees with Anamaria's analysis that 11x44 is the strongest component in aLIGO 27MHz signal.
In fact,

00x33 has the order of \frac{m_1^2 m_2}{16}+\frac{m_1^3}{48}

11x22 has the order of \frac{m_1^3}{16}

11x44 has the order of \frac{m_1^2 m_2}{8}

22x55 has the order of \frac{m_1^2 m_2}{16}

Therefore 11x44 is inherently the strongest contribution at 33MHz.
(And then, of couse, the signal amplitudes have additional dependences on the reflectivity
and the gain of the IFO at each freq)

If we believe this result, it may be difficult to exploit the benefit of the signals under the 3f cancellation.
We probably have to go back to the original idea of cancelling the 3f modulation by adding 3f modulation.
(i.e. Produce 33MHz signal by freq tripling, add this signal to Kiwamu's box to elliminate 3f.)

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