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Entry  Fri Mar 1 01:17:06 2013, Jenne, Update, LSC, Xarm oscillation POX11_630Hz_osc.pdf
    Reply  Fri Mar 1 16:58:37 2013, yuta, Update, LSC, Xarm oscillation stopped POX11_630Hz.png
       Reply  Sat Mar 2 00:09:31 2013, rana, Update, LSC, Xarm oscillation stopped 
Message ID: 8208     Entry time: Fri Mar 1 16:58:37 2013     In reply to: 8203     Reply to this: 8210
Author: yuta 
Type: Update 
Category: LSC 
Subject: Xarm oscillation stopped 

POX11 oscillation at 630 Hz was stopped by installing 630 Hz resonant gain to LSC_XARM.
After few hours, oscillation stopped. So I removed the resonant gain.
Our guess is that 630 Hz peak is some violin mode or something, and it was excited somehow, and didn't stopped for very long time because of its high Q. It coupled into POY11 somehow (scattering, electronics, etc).

Attachment 1: POX11_630Hz.png  32 kB  | Hide | Hide all
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