[ RadSafe ] Infinite Thickness of KCl

[Nielsen.Erik at epamail.epa.gov]

I am trying to determine the infinite thickness of the 1460 keV gamma 
emission (10.5% abundance) of a planar source of KCl (416 pCi/g) and a 
density of 1.98 g/cc.

In other words, what is the thickness of a KCl planar source where any 
additional thickness does not increase the surface dose rate?

I have scoured my references but have not located the appropriate formula 
for calculating this value.

I would appreciate any references or suggestions for an appropriate 
calculation.

Erik C. Nielsen
USEPA, National Air and Radiation Environmental Laboratory
540 South Morris Ave.
Montgomery, AL 36115
Phone 334-270-3475
Fax 334-270-3454

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