Total mass attenuation coefficients of aqueous solutions of urea. having co
ncentrations ranging from 0.06 to 0.22 g/cm(2), have been determined by per
forming transmission experiments in a narrow beam geometry at 662 keV. The
sphere transmission method has also been employed for the direct measuremen
t of mass energy absorption coefficients of these solutions by placing a po
int source of Cs-137 inside a spherical shell. Analysis of the experimental
data in terms of cross sections and effective atomic numbers is presented.