October 2000 anneal report for program 8841.

There was an anneal of the CCD on October 21th, 2000, 28 days after the
previous anneal on September 23, 2000. A homogeneous set of data was obtained
from proposal 8841:  The CCD Hot Pixel Annealing.

For the most part, previous trends continue. The growth rate of hot  pixels
continues within the average range seen for previous months. The flattening
seen over the last several months, in the mean post-anneal dark count-rate 
(MPADCR), is now more evident. A slightly lower value of the mean raw 
post-anneal dark count-rate, for this month, also suggest a tendency to a 
flattening with an average value around 0.24. In this anneal period the growth 
rate of hot pixels was less than that in previous months which results in a 
number of post-anneal hot pixels close to that of the previous anneal period.

1) The number of post anneal hot pixels continue increasing consistent
   with the previously determined long term trends. 
 
   > 0.1 e/s: 15719 pixels on Oct 21
   > 1.0 e/s:  3175
   > 10. e/s:   344

   > 0.1 e/s: 15690 pixels on September 23 
   > 1.0 e/s:  3181
   > 10. e/s:   353

   > 0.1 e/s: 15471 pixels on August 27 
   > 1.0 e/s:  3146
   > 10. e/s:   354

   > 0.1 e/s: 14875 pixels on July 28 
   > 1.0 e/s:  3016
   > 10. e/s:   337

2) The *raw* post-anneal dark countrate for this anneal is 0.02423 cts/pixel.
   This compares with 0.02444 cts/pixel in Sept 23, 2000, and 0.02034 cts/pixel 
   in Oct 1999. 
   
3) The iterated median count rate (after iterating up to 30 times by
   eliminating pixels +/- 5*sigma) is 0.00411, more than last month.
   
4) The creation rates for hot pixels over this period were within the normal
   range except for level 10 e/s where the number of hot pixel was less than
   after the anneal of last month.

   > 0.1 e/s:  20.7 pixels/day in Oct 21 2000 
   > 1.0 e/s:   2.5
   > 10  e/s:  -0.5

   > 0.1 e/s:  40.5 pixels/day in September 23 2000 
   > 1.0 e/s:   4.5
   > 10  e/s:   0.3

   > 0.1 e/s:  60.1 pixels/day in August 27 2000 
   > 1.0 e/s:  11.1
   > 10  e/s:   1.8

   > 0.1 e/s:  53.8 pixels/day in Oct 23 1999 
   > 1.0 e/s:   6.1
   > 10  e/s:   0.2


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

   > 0.1 e/s: 94.8% annealed away in the October 21 00 anneal.
   > 1.0 e/s: 108.8%
   > 10  e/s:  31.0%

   > 0.1 e/s: 79.2% annealed away in the September 23 00 anneal.
   > 1.0 e/s: 70.1%
   > 10  e/s: 111.0%

   > 0.1 e/s: 65.8% annealed away in the August 27 00 anneal.
   > 1.0 e/s: 59.5%
   > 10  e/s: 68.0%

   The usual plots are attached.