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Entry  Thu Oct 9 16:31:53 2014, ericq, Update, LSC, CARM W/N TFs carm2SQRTinv.pdfcarm2REFLDC.pdf
    Reply  Thu Oct 9 18:30:59 2014, Jenne, Update, LSC, CARM W/N TFs 6x
       Reply  Fri Oct 10 00:20:37 2014, rana, Update, LSC, CARM W/N TFs carm40.pngcarm.pdf
          Reply  Wed Oct 15 02:59:04 2014, rana, Update, LSC, CARM W/N TFs spring.pdfantispring.pdf
             Reply  Thu Oct 16 22:35:05 2014, rana, Update, LSC, CARM W/N TFs carm_spring.pdfcarm_antispring.pdf
       Reply  Wed Oct 15 13:38:33 2014, Jenne, Update, LSC, CARM W/N TFs 7x
          Reply  Mon Oct 20 17:50:30 2014, Jenne, Update, LSC, CARM W/N TFs (Others were all wrong!) 7x
Message ID: 10626     Entry time: Mon Oct 20 17:50:30 2014     In reply to: 10609
Author: Jenne 
Type: Update 
Category: LSC 
Subject: CARM W/N TFs (Others were all wrong!) 

I realized today that I had been plotting the wrong thing for all of my transfer functions for the last few weeks! 

The "CARM offsets" were correct, in that I was moving both ETMs, so all of the calculations were correct (which is good, since those took forever). But, in the plots I was just plotting the transfer function between driving ETMX and the given photodiode.  But, since just driving a single ETM is an admixture of CARM and DARM, the plots don't make any sense.  Ooops.

In these revised plots (and the .mat file attached to this elog), for each PD I extract from sigAC the transfer function between driving ETMX and the photodiode.  I also extract the TF between driving ETMY and the PD.  I then  sum those two transfer functions and divide by 2.  I multiply by the simple pendulum, which is my actuator transfer function to get to W/N, and plot.

The antispring plots don't change in shape, but the spring side plots do.  I think that this means that Rana's plots from last week are still true, so we can use the antispring side of TRX to get down to about 100 pm.

Here are the revised plots:




Attachment 1: PDs_vsCARMoffset_20Oct2014.mat.zip  1.245 MB
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