From mweber@head.cfa.harvard.edu Sat Jun 11 05:03:26 2005
Date: Sat, 11 Jun 2005 05:03:26 -0400 (EDT)
From: Mark Weber <mweber@head.cfa.harvard.edu>
To: Leon Golub <golub@head-cfa.harvard.edu>, Ed Deluca <deluca@head-cfa.harvard.edu>, Jay Bookbinder <jbookbinder@cfa.harvard.edu>, Jonathan Cirtain <jcirtain@head.cfa.harvard.edu>, Bill Podgorski <wpodgorski@cfa.harvard.edu>
Cc: Peter Cheimets <pcheimets@cfa.harvard.edu>, mario cosmo <mcosmo@cfa.harvard.edu>, Jason Scott <jscott@head.cfa.harvard.edu>
Subject: E2E 20050610 Shift-B Science Report.

Shift-B began with Section 16, Telescope Sensitivity. We took normal and 
dark exposures at BF focus position, for exposure indices ranging from 
64.5 millisec to 65.5 sec. Analysis has not been completed yet, but the 
data look fine.

We next repeated the On-Axis Best Focus sub-test to determine if the focus 
position had changed as a result of outgassing over the past few days. We 
plotted spot width versus focus positions from -1250 to -450 focus-steps, 
and fit the data with a 2nd degree polynomial. The best fit BF position 
was -880 steps = -531 um. This agreed within errors with the previous 
result of BF = -850 steps = -515 um. See Analysis webpage for plot. Since 
the instrument focal length has not appeared to change, we proceeded to 
move back to the original alignment (0, -1.2') from the beginning of 
testing.

We performed a Core PSF 2D scan. Plots are available on the Analysis 
webpage.

Next, we re-ran the 1D scans to search for the FOV Optimized Focus 
position. We started at ann earlier estimate of the Best Focus position 
(BF = -770 steps = -472 um). We did 1D "diameter" scans in pitch/yaw at 
BF+100um, BF+200um, and BF+300um. The last position is beyond the OF 
position. Plots are available on the Analysis webpage.

The CCD electronics have exhibited some strange behavior. We noticed in 
the 8x8 binned darks that there were some strange levels and "bands". This 
behavior varied without obvious cause. This issue was brought to the 
attention of the J-side, and they have started to investigate. We were 
able to provide them with a large set of darks for analysis. An initial 
observation is that the dark signal seems to jump among s few discrete 
levels.

--Mark Weber