Neutron activation analysis of ancient Burmese silver coins with a low flux americum/beryllium neutron source

ABSTRACTS Nondestructive neutron activation analysis is by now a well‐established technique for the analysis of ancient silver coins. The high activation cross‐section of silver for thermal neutrons makes it possible to also use this method with the low neutron fluxes available from an isotopic neutron source. In this case due consideration must be given to minimize the self‐shielding effect which is encountered with coins above a few tenths of a millimetre thickness. A simple method for the determination of the silver, copper and gold content in silver coins based on the self‐shielding properties of silver alloys of different fineness is described. The method has been found to be useful for the quick routine assay of silver coins for the purpose of their classification. Seventeen ancient Burmese silver coins from three different cultural periods of Burma, and two British coins for comparison have been analyzed by this method.