X-ray fluorescence in investigations of cultural relics and archaeological finds.

Some characteristic features of X-ray fluorescence (XRF) analysis make it an ideal method for investigations of cultural relics and archaeological finds. It has therefore become a standard method used in archaeometry. Paintings, frescos, manuscripts, pottery, metalwork, glass, and many other objects are analysed with the aim of recognising their materials, production technologies and origin, and for identifying counterfeits. This paper reviews various techniques used in XRF analyses of works of art, summarises the advantages and limitations of the method, and presents some typical examples of its use. The general review is supplemented by some techniques used and some results achieved at CTU-FNSPE in Prague.

Application of X-ray fluorescence in investigations of Bohemian historical manuscripts.

In this work we present the application of X-ray fluorescence analysis (XRFA) in an investigation of the Land Register and the Register of the Court of the Kingdom of Bohemia and the manuscript of the Homiliary of the Opatovice Monastery from the 12th century. Radionuclide sources emitting radiation at an appropriate energy level and an X-ray tube were used to excite the characteristic radiation. A spectrometric Si(Li) detector and a Si-PIN detector with Peltier cooling were used to detect the excited characteristic radiation. Several types of pigments were identified and compositions of inks used within almost 5 centuries in the offices at the Prague Castle were determined.

X-ray fluorescence analyzers for investigating postmediaeval pottery from Southern Moravia.

This paper deals with an investigation of ceramic archaeological finds with the use of in-situ X-ray fluorescence analysis. Firstly, three configurations of X-ray fluorescence analyzers constructed and used at the Czech Technical University in Prague are described and compared for use in a non-destructive survey of siliceous materials. Detection limits, depth of analysis, the relation of the analyzed area, the homogeneity of the samples, and variations in the element concentrations are discussed. Secondly, many shards of postmediaeval pottery from Southern Moravia are analyzed with X-ray fluorescence analysis and some of them also with electron microprobe analysis. Selected results are described.

Recognition of pigment layers in illuminated manuscripts by means of Kalpha/Kbeta and Lalpha/Lbeta ratios of characteristic X-rays.

X-ray fluorescence analysis with an evaluation of the Kalpha/Kbeta or Lalpha/Lbeta count rate ratios enables a layered structure to be recognized, because the measured ratio of two lines of one element depends on the depth distribution of this element in the analyzed objects. Several specimens consisting of layers of various pigments were analyzed to demonstrate the possibilities of the proposed technique. Then the Lalpha/Lbeta technique was applied in an investigation of cinnabar distribution in mediaeval manuscripts.

K(alpha)/K(beta) ratios of fluorescence X-rays as an information source on the depth distribution of iron in a low Z matrix.

This paper describes how the K(alpha)/K(beta) count rate ratio of the characteristic X-rays of a given element can be applied to determine the depth at which a layer or a grain of that element is located. The theoretical background and a basic description of the K(alpha)/K(beta) technique are given in the introduction. The experimental part of the paper deals with measurements of thick standard pure iron, intermediately thick iron foils, and layers prepared with a powder of Prussian blue. All these specimens were analyzed alone, and they were also analyzed overlaid with a low Z matrix. The light matrix consisted of sheets of paper of known thickness. Paper was chosen, because we take into account the subsequent application of this technique to surveys of historical monuments. The relation between the K(alpha) count rate, the K(alpha)/K(beta) count rate ratio, and the distribution of iron in the paper matrix are presented here.