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Entry  Sun Mar 8 03:27:48 2015, Jenne, Update, LSC, Error signal blending for CARM/DARM transitions 
    Reply  Sun Mar 8 04:04:19 2015, Jenne, Update, LSC, Error signal blending for CARM/DARM transitions 
       Reply  Sun Mar 8 13:51:41 2015, rana, Update, LSC, Error signal blending for CARM/DARM transitions 
          Reply  Mon Mar 9 14:14:32 2015, Jenne, Update, LSC, Error signal blending for CARM/DARM transitions First-ever_RFonly_lock_7March2015.pngSecond-ever_RFonly_lock_7March2015.png
Message ID: 11122     Entry time: Mon Mar 9 14:14:32 2015     In reply to: 11121
Author: Jenne 
Type: Update 
Category: LSC 
Subject: Error signal blending for CARM/DARM transitions 

Here is a longer stretch of data, from the first RF-only lock on Saturday night.  Unfortunately daqd had died about 400 seconds before the lockloss, so I can't show the RF signals coming on.  

ALS was on the _A channels for CARM and DARM, so when those go to zero (about -300 seconds for CARM, and about -200 seconds for DARM), we're using RF signals only for the error signals.

CARM noise definitely improves, but holy smokes does DARM start to look good!  Although, right at the end it starts to look like REFL11I is getting bigger.  Not sure why, but we'll have to watch out for this.

 


Here's the equivalent plot for the second lock stretch. This is the one that was handled by the carm_up script. It looks like I had about 150 seconds of RF-only lock here. 

DARM error is getting bigger with time jnear the end, even though I wasn't working on alignment here.  Zooming in, DARM is oscillating at 16.4 Hz, which is the bounce frequency.  I thought I had my bounce/roll filters on, but somehow it still got a little rung up.  It just rings up to a steady state though, it's not getting huge, so I don't know that it was the cause of the lockloss.

 

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Second-ever_RFonly_lock_7March2015.png
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