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Entry  Mon Jun 16 23:15:44 2014, Jenne, Update, LSC, IFO alignment recovery Note_061614_230723_0.jpg
    Reply  Tue Jun 17 17:14:14 2014, Manasa, Update, LSC, IFO alignment recovery 
       Reply  Tue Jun 17 21:49:13 2014, Jenne, Update, LSC, IFO alignment recovery 
    Reply  Wed Jun 18 11:57:44 2014, not Jenne, Update, LSC, IFO alignment recovery 
Message ID: 10053     Entry time: Tue Jun 17 21:49:13 2014     In reply to: 10051
Author: Jenne 
Type: Update 
Category: LSC 
Subject: IFO alignment recovery 

PRMI locking with REFL33 is fine.  As it was yesterday, it's a little wobbly without the ASC (just PRM oplev), but I don't know that it's any different than it used to be.  It'll hold for long periods of time, so I feel okay about it. 

When the PRMI is locked, you can push the "up" button on the ASC screen, and it'll turn down the PRM oplev gain by a large factor, and engage the ASC.  When you lose lock, press the "down" button to undo these changes.  (Probably the ifoconfig script should include the ASC down script).  These up and down scripts for the ASC are already included in the carm_up script (the ASC up), and the watch scripts which run a down script (including ASC down) for the whole IFO when ALS loses lock.  If the ASC is engaged, I get bored of watching it before the PRMi loses lock on its own, so I think it's okay.  (Let's say that means I've watched it stay locked for at least a few tens of seconds, but it looks like it always has with the ASC - like it'll stay forever).

The only thing that seems different about the PRMI is that I've increased the PRCL gain from -0.02 to -0.04.  This is a value that it was at some weeks ago, and then we turned it down for loop osc reasons, but now it doesn't want to catch lock with the lower value, and if I turn it down after it's locked, it has trouble holding on.  I have included this change into the PRMI sideband configure script.

I haven't tried anything creative like locking with REFL 165.  I also didn't lock with 11 or 55, since 33 just worked.

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