An Internal-Monitor Method for the Activation Analysis of Silver in Palladium with Thermal Neutrons

Abstract

Abstract An internal-monitor method has been developed to eliminate many of the errors probable with activation analysis. This method involves the measurement of the composed radioactivity of the species to be analyzed and of an appropriate internal-monitor, and the estimation of the ratio of the induced activity of both the species. The present report will describe the principles and the applicability of the method to the determination of a trace amount of silver in palladium by means of thermal neutron irradiation. After the silver activity is chemically separated from the irradiated sample, the γ-ray spectrum corresponding to the mixture of 110mAg and 111Ag formed by the β− decay of 111Pd is measured. Synthetic mixtures of silver and palladium with known weight ratios have been prepared to check the accuracy of the method. A good proportionality has been obtained between the ratios of the 110mAg to 111Ag activities and the ratios of the concentrations. By using this relationship, silver analysis can easily be achieved. Contents of silver in a palladium sample down to about 1 ppm can be determined with a relative error of within ± 2%. By this method the errors which arise from neutron flux irregularities and self-shielding effects can be avoided, and no correction for chemical yield is necessary.