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

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

BIRÓ Tamás* NUCLEAR METHODS IN ARCHAEOMETRY DEVELOPED IN THE INSTITUTE OF ISOTOPES Abstract - Nuclear methods, utilizing the radiation emitted by radioactive isotopes, have been developed and applied to specific archaeometric problems. A broad variety of museum objects and finds, such as jewels, coins, paintings, minerals, tools, has been analysed by X-ray fluorescence. An original version of gamma-activation was developed for noble element analysis and was successfully applied to old coins. Another novel method developed is thermocurrent dating, applied first to obsidian. The interpretation of the results needs further investigation. TL dating is reported in a separate article. X and y radiography complemented with metallography have been used to study Copper Age metal technology. Introduction The discovery of nuclear and X radiation offered new and unique possibilities to archaeometric research, but is was only in the second half of this century when, thanks to the development of high-intensity radiation sources (reactors, accelerators) and sophisticated detection techniques, the so called nuclear methods could occupy their welldeserved post. Nuclear methods in archaeometry may be classified as follows: i. Decay of specific nuclides. Examples: *^C, U/Th, Pb and K-Ar dating ii. Radiation induced atomic and nuclear transitions. Examples: XRF, NAA, GAA, PIXE analysis iii. Storage of radiation energy or structural damage. Examples: TL and TC dating and provenience studies, track dating iv. Modification of the radiation beam. Examples: XRD, X and gamma radiography. This paper, following the above classification, briefly reviews those studies which have been carried out in the Institute of Isotopes. The examples given are illustrative, most of the results were or will be published elsewhere. [1,2,4, 5, 7] Isotopic dating (i) No isotopic dating has been done in the Institute of Isotopes, however many of the methods utilizing this process are applied in the Institute of Nuclear Research, Debrecen. X-ray fluorescence (ii) The radioisotope excited energy-dispersive version of the XRF method is used as this enables us to perform direct nondestructive assays of precious objects. XRF is especially suitable for the rapid and cheap analysis of a large number of samples providing complete information of elemental composition above Z=12, but its sensitivity is limited. * Institute of Isotopes of the Hungarian Acedemy of Sciences H-1525 Budapest P.O.Box 77