[ RadSafe ] Alpha to Beta Ratio Source Indication

[Goff, Tom]

Does anyone know of a basis for determining if the source of radioactivity on a smear or air sample is natural, fission product or transuranic based on the alpha to beta ratio.  

For example, if the ratio is greater than 3 then the source could be Actinide; it the ratio is less than 0.5, the source could be fission product; if the ratio is between then natural radioactivity is indicated.

Does anyone know of a reference for these ratios?

Tom Goff
WIPP Radiological Services
505 234-8861
fax 505 234-6062
<mailto:Tom.Goff at WIPP.ws> 
B452
P.O. Box 2078
Carlsbad, New Mexico 88221