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Entry  Tue Jul 23 21:32:43 2013, Koji, Update, IOO, Found the cause of mysterious MC motion 
    Reply  Wed Jul 24 14:26:24 2013, rana, Update, IOO, Found the cause of mysterious MC motion 
       Reply  Wed Aug 21 19:26:19 2013, rana, Update, IOO, Found the cause of mysterious MC motion 
Message ID: 8917     Entry time: Wed Jul 24 14:26:24 2013     In reply to: 8913     Reply to this: 9046
Author: rana 
Type: Update 
Category: IOO 
Subject: Found the cause of mysterious MC motion 

Yes, this was not ELOG'd by me, unfortunately. This was the MC tickler which I described to some people in the control room when I turned it on.

As Koji points out, with the MCL path turned off this injects frequency noise and pointing fluctuations into the MC. With the MCL path back on it would have very small effect. After the pumpdown we can turn it back on and have it disabled after lock is acquired. Unfortunately, our LOCKIN modules don't have a ramp available for the excitation and so this will produce some transients (or perhaps we can ezcastep it for now). Eventually, we will modify this CDS part so that we can ramp the sine wave.

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