July 1999 Anneal Report for 8410

There was an anneal of the CCD on July 28, 1999, 27 days after the previous
anneal of 1 July. A homogeneous set of data was  obtained from proposal 8410:
The Continuing Monthly Anneal Monitor.  This was the first visit of proposal
8410, which is the continuation of proposal 8081.

As shown in the attached plots, the usual trends continue. At the 0.1 e/s
level, the post-anneal dark now shows 11584 hot pixels.

1) the *raw* post-anneal dark countrate for this anneal is 0.0184
   cts/pixel. This compares to 0.01805 cts/pixel on 1 July and 0.014820
   cts/pixel in Feb 99, consistent with a growth rate of 0.0066
   cnts/pixel/year.  This continues past trends.
   
2) the iterated median count rate (after iterating up to 30 times by
   eliminating pixels +/- 5*sigma) is 0.00318 cts/pixel, which continues
   the trend observed in previous months.

3) the creation rates for hot pixels over this anneal period were within
   the normal range found in recent anneals.

   > 0.1 e/s: 52.4 pixels/day in late July
   > 1.0 e/s:  4.9
   > 10  e/s:  0.5 

   > 0.1 e/s: 47.5 pixels/day in early July
   > 1.0 e/s:  5.2
   > 10  e/s:  0.5

   > 0.1 e/s: 42.6 pixels/day in May
   > 1.0 e/s:  5.6
   > 10  e/s:  0.5 

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

   > 0.1 e/s: 81.4% annealed away in late July anneal
   > 1.0 e/s: 92.4%
   > 10  e/s: 00.0%  
   
   > 0.1 e/s: 83.7% annealed away in early July anneal
   > 1.0 e/s: 25.6%
   > 10  e/s:200.0%  

   > 0.1 e/s: 84.5% annealed away in June anneal
   > 1.0 e/s: 62.7% 
   > 10  e/s: 43.8% 

   > 0.1 e/s: 70.3%  annealed away in May anneal
   > 1.0 e/s: 127.4%
   > 10  e/s: 154.5%


   Cumulative plots of total post-anneal hot pixels, and the new pixel anneals
   are attached.