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Entry  Tue Sep 18 18:24:50 2012, Jenne, Update, General, Scattering in BS chamber or ITMX chamber 
    Reply  Wed Sep 19 01:08:48 2012, Jenne, Update, General, DRMI aligned again DRMI_aligned_19Sept2012_ETMYwasHighNeedToFix.png
Message ID: 7405     Entry time: Wed Sep 19 01:08:48 2012     In reply to: 7402
Author: Jenne 
Type: Update 
Category: General 
Subject: DRMI aligned again 

The DRMI was aligned once again tonight. 

Here's a video: http://youtu.be/Cy8nHL9yMeM  (Can someone please tell me / remind me how to make the elog embed videos?!?)

Description of video:

Video capture of AS camera.
NOTE: The beam is a few centimeters above ETMY with this alignment, so it will not be final.

Beginning is ITMY only.
ITMX is realigned to form MICH.
PRM is realigned to form PRMI.
SRM is realigned to form DRMI.
PRM is misaligned to form SRMI.
ITMX is misaligned to form SRY.

With this alignment, I opened up the ETMY door to find the beam there.  The beam is ~half on, ~half off of the top of the glass baffle.  Not the top of the hole, but the top of the piece of glass.  This means that it's many centimeters too high at ETMY.  This helps explain why, while swinging PZT2 around the other day, I could not see any beam on the cage.  It did, however, look pretty close (within a centimeter....I didn't look closer than that since it was so off in pitch) to centered yaw-wise.

Tomorrow I'd like a Clean assistant to help tweak PZT2 to hit the center of ETMY.  We'll need to put the 45 degree target back on to make sure that we don't end up pointing funny down the arm.  Then I'll realign the DRMI one more time.

Tonight, I can't check the full AS path, or any of the REFL path once it diverges from the main path.  Steve's new contraption (which is awesome!) doesn't have doors/windows yet, so I can't open it to get an IR card anywhere near any optics in the IOO or OMC chambers.  I waved PRM around a bit, but I can't find the beam on the REFL camera, so I definitely need to check that whole path again before we close up.

So, we're not closing up tomorrow, but progress has been made, and we're getting closer.

Note to self:  These are the ITMX, ITMY, PRM, BS, SRM biases with this DRMI alignment.  The DRMI is good, but the arms aren't, so these won't be final.  The saved alignments are still those with (for the Yarm) the beam bouncing several times between ITMY and ETMY.  BS was aligned at the time to hit the center of ETMX, and PRM and SRM should be retro reflecting in that alignment.  So, it's possible, that aligning PZT2 to hit the center of ETMY and restoring all of the optics will get me close to being back to DRMI aligned, but in a condition that the arms are align-able too.

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