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Entry  Tue Aug 4 23:03:56 2009, alberto, Update, Locking, IFO Alignment 
    Reply  Wed Aug 5 09:48:05 2009, alberto, Update, Locking, IFO Alignment 2009-08-09_FSStransPD.png2009-08-09_FSreflPD.png
       Reply  Thu Aug 6 09:33:08 2009, alberto, Update, Locking, FSS Transmitted and Reflected Power Trends 2009-08-06_PSL_trends200days.png2009-08-06_PSL_trends.png
          Reply  Thu Aug 6 10:32:45 2009, alberto, rob, Update, Locking, More PSL trends: NPRO, MOPA, FSS, PMC and MZ 2009-08-06_PSLtrends.png
Message ID: 1833     Entry time: Wed Aug 5 09:48:05 2009     In reply to: 1830     Reply to this: 1842
Author: alberto 
Type: Update 
Category: Locking 
Subject: IFO Alignment 


After the mini boot fest that Jenne did today, I checked whether that fixed the overflow issues we yesterday prevented the alignemnt of the arms. 

I ran the alignment script for the arms getting 0.85 for TRX and 0.75 for TRY: low values.

After I ran the script ,C1SUSVME1 and C1SUSVME2 started having problems with the FE SYNC (counter at 16378). I rebooted those two and fix the sync problem but the transmitted powers didn't improve.

Are we still having problem due to MC misalignment?

I also noticed that the FSS transmitted power has been constantly decaying for the last 6 months. Only in the last month tt dropped by 15%. The laser power hasn't decayed as much, so it's probably not the cause.
Maybe this is one reason why lately of less power going to the IFO.
We call it FSS Transmission, but I guess we mean power transmitted TO the IFO, that is it measures the power reflected from reference cavity, right?
Still on the front of the FSS, the reflected power has dropped from -0.5 to -1.2. Here I also wonder about the reason of negative values for that.

See attachments

Attachment 1: 2009-08-09_FSStransPD.png  14 kB  | Hide | Hide all
Attachment 2: 2009-08-09_FSreflPD.png  9 kB  | Hide | Hide all
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