X-ray fluorescence in the study of cultural heritage

Luísa Carvalho

The study of the elemental composition of an art work is the first step to restore its history. Part of the history of objects and of the way of life of civilizations is held in the materials in an atomic scale. This is the information that Physics will search. In the past years several portable X-ray equipments have been developed allowing in situ elemental analysis of objects, that otherwise wouldn´t be studied. It’s possible to bring the equipment to places of interest such as museums or archaeological sites, allowing the characterization of the manufacturing techniques, to identify fakes and restorations or even to know the environmental conditions and feeding habits of lost civilizations.

X-ray fluorescence is one of the most popular techniques and it’s a perfect tool to study the elemental composition of those art works since it allows its analysis without the need of samples and without causing any damages. It also allows studying objects that can’t be moved from its original places, due to its weight and dimensions, or to its value.

This technique has a simple physical principle. A primary beam of radiation X ionizes, in an internal level, the atoms of the sample. When these atoms return to their fundamental stage they emit radiation that equals the difference of energy between each level of transition. This energy has a specific value for each element in the sample, allowing their identification.

Will be given several examples of the identification and characterization of art works using XRF, showing its potential as a none destructive elemental analysis.