Re: External Dose Constants for Beta Emitters -Reply

[FRAMEP@ORAU.GOV]

Greetings:

I've always imagined beta dosimetry to be an area where angels fear
to tread. Nevertheless:

W.G. Cross (who knows his beta dosimetry) published a note in Health
Physics Vol.11 pp 453-454, (1965) entitled "Rough Estimates of Beta
Doses to the Skin".  

The following is a quote: "The proposed rule of thumb for sources
emitting one beta particle per disintegration is "A 1 mc [mCi] point
source gives a skin dose rate of 5 rad/hr at 10 cm" An almost
equivalent expression, easier to remember, is "A 1-mc point source
gives a skin dose rate of 1 rad/min at 1 inch"."  This approximation
however is meant to apply to beta emitters with maximum energies
above 300 keV or so - not for H-3, C-14 etc.

For what its worth.

Paul Frame
Professional Training Programs
Oak Ridge Associated Universities
framep@orau.gov