December 2001 anneal report for program 8841.

There was an anneal of the CCD on Dec 15, 2001, 26 days after the previous
anneal on Nov 19, 2001.  A homogeneous set of data was obtained from proposal
8841:  The CCD Hot Pixel Annealing.

Previous trends continue.  The growth rate of hot pixels continues within the
range seen for previous months.

1) The number of post-anneal hot pixels has increased at the highest levels,
   but decreased at the lowest level, the opposite of last month.

   > 0.1 e/s: 15801 pixels on Dec 15, 2001
   > 1.0 e/s:  3340
   > 10. e/s:   387
   
   > 0.1 e/s: 15839 pixels on Nov 19, 2001
   > 1.0 e/s:  3250
   > 10. e/s:   346
   
   > 0.1 e/s: 15589 pixels on Oct 19, 2001
   > 1.0 e/s:  3266
   > 10. e/s:   365
   
   > 0.1 e/s: 15230 pixels on Sep 21, 2001
   > 1.0 e/s:  3228
   > 10. e/s:   361


2) The *raw* post-anneal dark countrate for this anneal is 0.02550 cts/pixel.
   This compares with 0.02398 cts/pixel a month ago, and 0.02434 cts/pixel 
   a year ago.
   
3) The iterated median count rate (after iterating up to 30 times by
   eliminating pixels +/- 5*sigma) is 0.00421, up from last month.

4) The creation rates for hot pixels over this period were within the normal
   range of fluctuations.

   > 0.1 e/s:  31.0 pixels/day in Dec 2001
   > 1.0 e/s:   7.8
   > 10  e/s:   2.3

   > 0.1 e/s:  10.6 pixels/day in Nov 2001
   > 1.0 e/s:   2.5
   > 10  e/s:   0.0

   > 0.1 e/s:  25.7 pixels/day in Oct 2001
   > 1.0 e/s:   2.6
   > 10  e/s:   0.0


   > 0.1 e/s:  30.9 pixels/day 1 year ago
   > 1.0 e/s:   3.4
   > 10  e/s:   0.1


5) The rate at which new hot pixels annealed out was within the normal range of
   fluctuations.

   > 0.1 e/s: 104.9% annealed away in the Dec 15, 2001 anneal
   > 1.0 e/s:  53.8%
   > 10  e/s:    28%
   
   > 0.1 e/s:  21.4% annealed away in the Nov 19, 2001 anneal
   > 1.0 e/s: 121.1%
   > 10  e/s:  2000%
   
   > 0.1 e/s:  46.3% annealed away in the Oct 19, 2001 anneal
   > 1.0 e/s:  43.3%
   > 10  e/s:  -300%


   The usual plots are attached.