The direct measurement of Ba-133 activity by the sum-peak method

The subject is a direct measurement of the activities of Ba-133 sources by application of the theoretical count rate expressions recently developed by Novkovic et al. The total uncertainties of the activity of the measured sources, obtained in two manners, are described in this paper. The presented method is successfully tested using a germanium spectrometer with efficiencies of 50%. The accuracy of this method is proved to be comparable with the present methods of the activity measurement of Ba-133. (c) 2009 Elsevier B.V. All rights reserved