Vadas Ferenc (szerk.): A Wosinszky Mór Múzeum Évkönyve 15. (Szekszárd, 1990)
Die awarischer Kultur - Márta Balla: Provenance studies of avar ceramics by neutron activation analysis
Provenance studies of avar ceramics by neutron activation analysis MÁRTA BALLA, BUDAPEST Chemical techniques have been brought to bear on archeological remains ever since chemistry became recognizable science. There are now several laboratories dedicated to the scientific study of ancient artifacts. In the Institute of Nuclear Techniques of the Technical University Budapest we have been dealing with provenance studies of archaeological ceramics using NAA since 1980. Our studies bear the implicit assumption that pottery produced in a particular area has a distinctive chemical composition, carries a specific geochemical fingerprint. So by analysing the chemical composition sherds made in a given place and time perhaps excavated from distant sites can be grouped and separated from others made in other workshops. The chemical composition marks the geological-geochemical antecedents of the raw material and phases of manufacturing, too. This is especially true for accessory and trace elements. The change of concentration of these elements is not restricted by stoichiometrical rules in the respect of the principal components. That is why to our opinion the determination of trace elements is more important than that of the main components for their greater variability assumes more certain separation. Provenance studies i.e. grouping the sherds to workshops according to their chemical composition makes demands on the analytical method used. The aim is to apply a well automatized measuring method which assumes a more sensitive determination of elements and at the same time it ensures objectivity, reliability and reproductivity required by the task. NAA can satisfy all the requirements mentioned above. This is the most widespread analytical method applied in the studies of provenance of ceramics. The basic principles of activation analysis can be broken down into three elementary steps: the activation, detection and final analysis. The sample to be analysed is first activated by exposure to a source of neutrons (generally in a nuclear reactor) thus producing the radioactive isotopes of the elements in the sample by nuclear reactions. These isotopes emits radiation of different type and energy. By detecting the gamma-rays emitted by our sample we can make qualitative and quantitative determinations i.e. we can determine that what kind of elements in what concentrations construct the sample (1). The basis of the quantitative analysis is to determine the energy of the gamma-quants coming from the examined radioactive isotopes. The measuring of the intensity of radiation is used for quantitative analysis. The measurements are carried out by the following steps. The surface of the ceramics is to be cleaned by a diamond grinder at the place of sampling. 131
