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Entry  Thu Oct 18 03:57:20 2012, Jenne, Update, Locking, Alignment is really bad?? 
    Reply  Fri Oct 19 16:24:39 2012, rana, Update, Locking, Alignment is really bad?? 
       Reply  Fri Oct 19 16:45:39 2012, Steve, Update, VAC, vent has started 
          Reply  Fri Oct 19 19:26:42 2012, Jenne, Update, VAC, vent has started 
             Reply  Mon Oct 22 09:10:07 2012, Steve, Update, VAC, @750Torr ventOct222012.png
                Reply  Tue Oct 23 08:45:00 2012, Steve, Update, VAC, vent day 3 ventd4.pngIMG_1743.JPG
Message ID: 7573     Entry time: Thu Oct 18 03:57:20 2012     Reply to this: 7581
Author: Jenne 
Type: Update 
Category: Locking 
Subject: Alignment is really bad?? 

The goal of the night was to lock the Y arm.  (Since that didn't happen, I moved on to fixing the WFS since they were hurting the MC)

I used the power supplies at 1Y4 to steer PZT2, and watched the face of the black glass baffle at ETMY.  (elog 7569 has notes re: camera work earlier)  When I am nearly at the end of the PZT range (+140V on the analog power supply, which I think is yaw), I can see the beam spot near the edge of the baffle's aperture.  Unfortunately, lower voltages move the spot away from the aperture, so I can't find the spot on the other side of the aperture and center it.  Since the max voltage for the PZTs is +150, I don't want to go too much farther.  I can't take a capture since the only working CCD I found is the one which won't talk to the Sensoray.  We need some more cameras....they're already on Steve's list.

When the spot is a little closer to the center of the aperture than the edge of the aperture (so the full +150V!!), I don't see any beam coming out of AS....no beam out of the chamber at all, not just no beam on the camera.  Crapstick.  This is not good.  I'm not really sure how we (I?) screwed up this thoroughly.  Sigh.  Whatever ghost REFL beam that Kiwamu and Koji found last week is still coming out of REFL.

Previous PZT voltages, before tonight's steering:  +32V on analog power supply, +14.7 on digital.  This is the place that the PRMI has been aligned to the past week or so.

Next, just to see what happens, I think I might install a camera looking at the back (output) side of the Faraday so that I can steer PRM until the reflected beam is going back through the Faraday.  Team K&K did this with viewers and mirrors, so it'll be more convenient to just have a camera.

Advice welcome.

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