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Entry  Fri Jul 29 16:25:06 2011, kiwamu, Update, ASC, beam axis and Y arm aligned 
    Reply  Sat Jul 30 06:24:06 2011, kiwamu, Update, ASC, Y arm ASS fixed 
       Reply  Sat Jul 30 21:04:23 2011, kiwamu, Update, ASC, Y arm ASS fixed 
       Reply  Sun Jul 31 00:05:52 2011, kiwamu, Update, LSC, script for loss measurement : modified 
          Reply  Sun Jul 31 22:35:35 2011, kiwamu, Update, LSC, arm loss measurement : done 
             Reply  Wed Sep 7 16:21:35 2011, kiwamu, Update, LSC, arm loss measurement : resluts Yarmloss.pngXarmloss.png
                Reply  Wed Sep 7 17:28:41 2011, kiwamu, Update, LSC, X arm loss measurement : not good Xarmlossmeasurement.png
Message ID: 5359     Entry time: Wed Sep 7 16:21:35 2011     In reply to: 5077     Reply to this: 5360
Author: kiwamu 
Type: Update 
Category: LSC 
Subject: arm loss measurement : resluts 

Here are the results of the arm loss measurements, which I have done before the vent.

I ran the existing matlab script, called 'armLoss.m', to estimate the loss. The script resides in /scripts/LSC.

(Y arm)

 Round trip loss =  154.668624 +/- 11.343204 ppm


The figure above is a time series of the measurement.

In the lower plot the power in the ASDC_PD are plotted. The green dotted-curve is the power when the Y arm is unlocked.

The blue dotted-curve is the one when the Y arm is locked.

In the upper plot the estimated loss from each combination of locked/unlocked power are plotted.


(X arm)

Round trip loss = ????? 50 ppm ?????

The obtained time series looked wired because difference in the ASDC power when the arm was locked/unlocked were small.

This small difference results in such a small loss.

To see what was going on I will look at the trend data.


Quote from #5077

I did the measurement of the arm loss on both X and Y arm by running the armLoss script.

The results will be posted later.


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