M. Járó - L. Költő szerk.: Archaeometrical research in Hungary (Budapest, 1988)

Analysis - BIRÓ Tamás: Nuclear methods in archaeometry developed in the Institute of Isotopes

rical Museum of Budapest on the hoard of 38 silver coins and intermediates found at Máriaremete in a counterfeiter mint from the time of King Stephan V (1239-1272). The compositions of two coins shown in Fig. 3 illustrate that the false coins were made from different, presumably stolen, objects. An original version of photo- or gamma activation (GAA) was developed in the Institute of Isotopes: nuclear isomers of certain nuclides can be excited by 1—3 MeV gamma rays from high-intensity radiation sources, such as °^Co and ^^La. The sensitivity is in general much lower than for NAA, but the selectivity is better and no residual radioactivity is left in the sample. In contrast to XRF this method gives a volume response. It is particularly suitable for the analysis of noble elements, e.g. coins. Table 3 shows some of the results obtained in the analysis of ancient coins from the Hungarian National Museum [4]. Cu[_J t I Au 1 I Pb _J f ai King Géza Fig. 2 XRF spectra of coins from King Géza and King Salamon