Non-destructive investigation of Cultural Heritage microsamples by XRF/XRD-CT: new insights on a medieval decoration technique from the Duch

The aim is to perform coupled X-ray fluorescence/diffraction computed tomography (XRF/XRD-CT) to investigate medieval adornments called "applied brocades". Previous works have highlighted singular layer superimpositions and specific trends in the making of these sophisticated decors, which could be characteristic of a know-how specific to the Duchy of Savoy. We now need to extend the corpus by studying well selected micro-fragments taken on sculptures and mural painting. We want to investigate the overall sequence of the stratigraphy and specifically the nature of the gilding and the tin degradation products. For this, we will make the 3D mapping of the elements/phases with a probe size adapted to the quite large dimension of the fragments, sampled so as to preserve the entire stratigraphy. The D2AM beam line with a 25 keV beam focused to about 20 x 20 μm2 and with a 2D detector to collect diffraction patterns in a short time is ideally suited for this experiment.