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Report on October 2010 SHARP setup:
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Overview:
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During Oct 26-28 I removed the 450 micron HWP and installed the 350 micron 
HWP.  I verified that the optical alignment was within spec. Then I tested 
the system via "fake observing".  Basically, everything seems to be 
working well, though there is some odd behavior in the IRC-to-EDAS link 
which has me slightly concerned.  But hopefully it will be OK.  The odd 
behavior is described in the last section below.  I did not test the 
chopper.

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HWP swap:
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I did not implement the new wavy washer system that we implemented for the 
first time in July 2010 using the 450 micron plate.  Instead, I used the 
older cork system.  This is due to a design flaw in the HWP pocket in the 
brass piece that the HWP slides into.  It should have a diameter of around 
4.005" but it is closer to 4.000".  This can be changed in future though 
it is a bit of work.  The cork has worked well for the 350 micron HWP in 
the past so it should be OK.  I aligned the HWP according to the usual 
marks.

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Optical alignment:
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subarray misalignment was measured to be 0.2 pixel, and parallelism was 
measured to be 0.1 pixel.  This is within spec; I decided not to make any 
adjustments.

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System tests: 
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"Fake observing" was done, which tests whether all computers are talking.  
Via a "SHARP Single File" I verified that the telescope was nodding and 
the HWP was advancing and the HWP angles were being stored to the data 
file (i.e. I ran readsharc on the fake data file and got the usual 
"steps").  As noted above there was some odd behavior of the EDAS-to-IRC 
link.  This is described in the last section of this report.

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Grid Test:
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The quick Vnull grid test was done and Vnull was found to be around 96, 
indicating that the HWP flag is around 90, as always for this 350 HWP. A 
more careful analysis will be done later.

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Odd Behavior in the EDAS-to-IRC link:
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Two differences were noted in comparison with recent behavior.

(1) One time the system did not start properly.  On Tuesday the system 
started up fine, but on Wednesday, the first time I tried to move the 
half-wave plate via the "SHARC Controls" window, I got a dialog box that 
said: "Polarimeter not Currently Available".  I went to the EDAS web page 
and verified that hwp.exe was running.  Then I shut down the client and 
server, power cycled the EDAS, and started up the server and client again.  
It worked fine.  I repeated this EDAS-server-client shutdown/startup 
sequence two more times as a test, and it worked both times.  On Thursday 
the system started up fine.  So we are 5 for 6 on successful EDAS-IRC 
startups in October 2010.  I can't think of anything I did to cause the 
one failure.

(2) The second difference is that when the IRC server starts up, it now 
prints the following line 30 times in a row:

InitializePolarimeter.run

Both Darren and I agree that it never used to do this so many times.  My 
memory is it used to print this message about 5-10 times in a row.

This is all a bit worrisome but I think probably it will be OK.  I plan to 
alert everyone who has expertise that is relevant to the EDAS-IRC link so 
they can be on standby in November in case of problems. 

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