RE: Rule of Thumb for BETA contamination

["Kent N. Lambert" <lambert@auhs.edu>]

On  2 Oct 97 at 10:25, Sorensen, Tony wrote:

> 
> Shapiro (1990) offers the following (table 2.1):
> 
> Dose rate from 100 beta particles per second per cm-2 equals   =
> approximately:
> 
> 56 mrad/hr (C-14); 33 mrad/hr (Ca-45); 11 mrad/hr (P-32); 11 mrad/hr
>   = (Sr-90). Note:  Parallel beam (Jaeger, 1968, p. 14).

In reviewing the above referenced table, I'm now confused.  The above 
decreases wrt energy.  But the absorbed dose rate to skin from 
surface contamination (measured in activity per sq cm) increases wrt 
energy.  I would expect that the beta particle flux (or is it 
fluence?) would be directly proportional to activity per unit area.  
So what changes the function from a negative to positive wrt energy?

Kent N. Lambert, M.S., CHP
lambert@auhs.edu
Allegheny University of the Health Sciences
Hahnemann Division
Radiation Physics and Safety, MS 106
Broad and Vine Streets
Philadelphia, PA  19102-1192

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