A METHOD FOR QUANTITATIVE ESTIMATION OF ACTIVITY DUE TO VARIOUS RADIONUCLIDES IN THE TERRESTRIAL AMBIENT ENVIRONMENT

The identification of radionuclides emitting gamma-rays in the ambient environment is an easy task, especially with high resolution HPGe det ectors. But the quantification of their activities is relatively diffi cult in the absence of any information regarding the location of these radionuclides in space relative to the detector. In this paper this p roblem has been attacked. The average efficiency function of the detec tor for field gamma-rays has been obtained by simulating the actual si tuation with an imaginary sphere surrounding the detector in 4pi space . Using this method the radionuclide concentrations have been obtained and the results have been compared with the concentrations deduced us ing high volume sampling of radionuclides on glass fibre filter papers followed by counting with a HPGe detector. The present method compete s quite well with the direct sampling method.