The PUMA beamline, created for the heritage community and accessible by all fields of science, welcomed its first users in 2019. Its optical layout uses a horizontal focusing mirror to prefocus the light emitted from the wiggler source for the experimental endstation. It provides a 5 µm × 7 µm microbeam for XRF, XAS, XRD and XEOL analysis or a wide 20 × 5 mm full field when the beam is defocused, and the KB mirrors are retracted. An extremely stable fixed-exit Si(111) monochromator is used to select the wavelength. Many experiments have been performed at PUMA, particularly in archaeology, paleontology, conservation, art history and in identifying safer conditions of irradiation for precious heritage samples. XRF analysis has been used, for example, to show the effects of the interaction of Palaeolithic ivory with soil; to identify the elemental composition of mineralized textiles and to reveal hidden morphologies of fossils.

Egyptian blue and green are among the oldest synthetic pigments produced by humanity. The two pigments are complex multi-phase copper-based systems synthesised with different protocols from the same raw materials. Since the 2000s, synchrotron X-ray techniques have provided significant new insights on their chemistry and microstructure. However, the potential impact of high flux irradiation of these pigments has not yet been studied despite the fact that it can lead to visual discoloration and less readily observable alterations such as defects formation or redox changes. In this work, we investigate the effects of synchrotron X-ray irradiation on Egyptian blue and green samples. Radiation-induced effects are monitored after irradiation at increasing doses using electron paramagnetic resonance (EPR) spectroscopy at temperatures of 290 K and 30 K. The cupric ion (Cu²⁺) is in D_4h axial geometry in Egyptian blue and in disordered geometry in Egyptian green, which makes the two pigments very easily identifiable by EPR. Egyptian green samples are found to be much more sensitive to X-rays than Egyptian blue. In particular, a browning of the green samples is observed from the lowest doses tested while no color change is detected for the blue ones. Three types of radiation-induced defects are detected after irradiation: E′, non-bonding oxygen hole and aluminum hole centers. Correlations between defect intensity and dose are calculated. Archaeological and modern pigments (whether blue or green) do not show the same reactivity to X-rays, which opens the prospect of using radiation-induced defects as a marker of their history.

Looting and plough damage to the eighth–fifth centuries BC tumulus of Creney-le-Paradis, France, hinders interpretation of this potentially significant site. Nevertheless, application of novel microtomographic techniques in combination with optical and scanning electron microscopy allows the first detailed examination of 99 textile fragments recovered from the central pit. The authors argue that the diversity of textiles revealed—at least 16 different items—and the quality of weaving involved confirm earlier interpretations of the high status of this burial, which is comparable, at least in terms of textiles and metal urns, with other ‘aristocratic’ tombs of the European Iron Age.