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Entry  Tue Feb 4 16:43:50 2014, manasa, Update, General, IFO alignment update 
    Reply  Tue Feb 4 17:40:19 2014, manasa, Update, General, Ready for pump down?? 
       Reply  Tue Feb 4 23:01:24 2014, Jenne, Update, General, Ready for pump down?? 
          Reply  Wed Feb 5 15:26:57 2014, manasa, Update, General, Ready for pump down?? 
       Reply  Mon Feb 10 16:02:12 2014, Jenne, Update, General, PRM oplev clipped in vacuum Screenshot-Untitled_Window-1.png
          Reply  Mon Feb 10 16:20:28 2014, Jenne, Update, General, PRM QPD recentered 
             Reply  Mon Feb 10 18:59:25 2014, Jenne, Update, ASC, PRM ASC better, but not great yet 
                Reply  Mon Feb 10 19:56:10 2014, rana, Update, ASC, PRM ASC better, but not great yet 
Message ID: 9619     Entry time: Mon Feb 10 18:59:25 2014     In reply to: 9617     Reply to this: 9620
Author: Jenne 
Type: Update 
Category: ASC 
Subject: PRM ASC better, but not great yet 

I have turned off the 3.2Hz res gains in the PRC ASC loops, since those seem to make the loops unstable. 

Right now the pitch gain is -0.001, with FM1,3,9 on.  Yaw gain is -0.004, with FM1,3,9 on. 

Pitch gain can't increase by factor of 2 without oscillating. 

I tried to take transfer functions, but I think the ASC situation is really confusing, since I have OSEM damping, oplev damping, and this POP QPD damping on the PRM.  It's hard to get coherence without knocking the PRC out of lock, and it keeps looking like my gain is 0dB, with a phase of 0 degrees, from ~1 Hz to ~10 Hz.  Outside that range I haven't gotten any coherence.  Moral of the story is, I'm kind of puzzled. 

Anyhow, as it is right now, the ASC helps a bit, but not a whole lot.  I increased the trigger ON value, so that it shouldn't kick the PRM so much.  I wish that I had implemented a delay in the trigger, but I'm not in the mood to mess with the simulink diagrams right now.

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