# Synchrotron X-ray Microprobes: An Application on Ancient Ceramics
###### Abstract
Otherwise, the use of nano-beams for acquiring details on single layers, characterize crystallites, investigating the element distribution at sub-micrometric scale, or performing transmission XANES maps require the preparation of thin sections or microtome sections. The use of \(\upmu\) and nano-beams implies in general higher localized radiation doses in the sample, as the flux is focused on a smaller spot size. However, in ceramic studies radiation damage is usually not a big issue. Sample preparation depends also on beamline set-up; for example, it is possible to perform the analysis in air--even on big objects or entire vessels--or in vacuum--which often requires microtome sections. Looking at the International Synchrotron Radiation Facilities, Table 1 reports a list of beamlines particularly suitable for material sciences applications, some of which are specifically optimized for cultural heritage studies, with details about energy range (which elements can be detected, mapped and for which the speciation can be determined), beam size (level of resolution) and sample environment (sample preparation required, vacuum or air, big or small samples). The overall listed information appears quite relevant in designing a successfully experiment, depending on the archaeological question to be answered. Among ancient Greek ceramics, red and black figures wares and black-gloss wares have a great interest both from the stylistic/typological point of view and the provenance and technological aspects. In fact, their analysis might draw the mobility of goods and/or painters and artisans through Greece and the western-Greek colonies. The identification of specific chemical markers to discriminate productions--especially among western-Greek colonies--is not straightforward due to high deputation of raw materials. In addition, even if the current literature mainly agrees on the technological routine applied in ancient time to obtain well manufactured red, black or red and black gloss wares, some issues remain still open [29; 31; 32]. To explore the challenges offered by SR-based X-ray microbeams in provenance and technological studies of ancient ceramics, fragments of black-gloss ware from different Greek and western Greek colonial products have been selected--as examples--and investigated at PUMA beamline of the SOLEIL Synchrotron Radiation Facility [33]. The selection of this beamline allowed (i) the determination of elements with emission energies higher than 10 keV, relevant in provenance and technological studies; (ii) obtaining micrometric lateral resolution (microbeam) for the determination of enrichment/depletion of elements in layers micrometric in thickness (black gloss); (iii) collecting both XRF and XANES maps at micrometric scale; (iv) to use samples without specific sample preparation due to the analysis being carried out in air, with a relatively flexible sample stage to accommodate fragments with different shapes or even entire vessels. For the purpose of comparison, other classical non-destructive and non-invasive (at micro-sample level) microchemical methods were used and the results are discussed in the light of the SR X-ray data.