A method for quantitative estimation of activity due to various radionuclides in the terrestrial ambient environment

The identification of radionuclides emitting γ-rays in the ambient environment is an easy task, especially with high resolution high-purity Ge (HPGe) detectors. But the quantification of their activities is relatively difficult in the absence of any information regarding the location of these radionuclides in space relative to the detector. In this paper this problem has been attacked. The average efficiency function of the detector for field γ-rays has been obtained by simulating the actual situation with an imaginary sphere surrounding the detector in 4π space. Using this method the radionuclide concentrations have been obtained and the results have been compared with the concentrations deduced using high volume sampling of radionuclides on glass fibre filter papers followed by counting with a HPGe detector. The present method competes quite well with the direct sampling method. (author)