Re: Bi207

["Dale E. Boyce" <dale@radpro.uchicago.edu>]

I calculate that you have a nominal 60 uCi source based on
the assumptions that your detector is tissue equivalent and
that there is no self absorption of photons above 70 KeV,
and total self absorption of photons below 70 KeV.  The calculation
is based on the photon branching ratios given in The Table of
Radioactive Isotopes, and mass energy absorption coefficients
in muscle.  The mass energy absorption coefficients were taken
from an empirical fit to the data from Hubbell (1969) as tabulated
in Tsoulfanidis "Measurement and Detection of Radiation".

Dale E. Boyce
dale@radpro.uchicago.edu