Photon absorptiometric studies of elements, mixtures and substances of biomedical interest

Photon absorptiometric measurements of several elements, mixtures and substances of biomedical interest have been performed. The 144.5 keV photons of 141Ce and the associated x-ray emissions of 203Hg at 75 keV and 137Cs at 33 keV in addition to the more commonly applied energies of 279.2 and 661.6 keV respectively, have been utilised. The concept of effective atomic numbers and the choice of tissue-equivalent substitutes has been examined with reference to the experimental findings. (author)