Full‐field XRF instrument for cultural heritage: Application to the study of a Caillebotte painting

Abstract

A novel full‐field X‐ray fluorescence spectrometer developed for cultural heritage applications is presented. Named “CartiX,” it was designed for routine deployment in the field (museum, archeological site) and uses a concept under development at NASA for planetary exploration. CartiX utilizes 2 miniature X‐ray tubes, a square pore Micro‐channel Plate X‐ray Optic, and a direct‐illumination CCD camera to collect spatially resolved X‐ray fluorescence data from an area of 13 x 13 mm2. We report here the application of CartiX to the analysis of a Gustave Caillebotte painting directly in the exhibition room. The Impressionists are renowned for their painting technique and their approach in capturing the effects of light in nature through a new use of color. They adopted innovative artistic practices consisting of short brushstrokes of unmixed colors that barely convey forms and give an effect of spontaneity and effortlessness that masks their often carefully constructed compositions. Here, we use high spatial resolution chemical data measured with CartiX to reveal the artist's complex use of pigments and the formation of alteration products and to help in the interpretation of the artist's choice of materials and their manipulation with small and thin brushstrokes.

X-ray computed tomography (XCT) and chemical analysis (EDX and XRF) used in conjunction for cultural conservation: the case of the earliest scientifically described dinosaur Megalosaurus bucklandii

“…XCT has been used in many different contexts, including assessing the condition of sensitive objects such as scrolls [28, 54, 61, 62], furniture [17], instruments [15, 63], building materials [24, 25], sculpture [27], statuary in stone, wood and bronze [64–67], paintings [26], identifying artefacts embedded in soil blocks extracted from archaeological sites [68], identifying the contents of unlabelled plaster casts [69], identifying structures obscured by corrosion crusts [70, 71] and weaponry [72] among a substantial variety of other conservational applications within the field of cultural heritage. XRF and EDX, although XRF more so, are commonly used techniques within the field of cultural heritage and have been utilised in many applications, dominantly in assessing the condition of paintings and the materials they are made from [73, 74]. XRF has also been used in many other contexts as well however, including as stone archaeological objects [75], weaponry [76], tracing provenance of archaeological materials [77, 78], evaluating the composition of writing materials [79, 80], metallic artefacts and coins [81, 82] among a myriad of other disparate applications.…”

“…These examples demonstrate the widespread use of these methods in conservation, but much less common is their paired application. XRF is most commonly applied to paintings, which given their high aspect ratio do not normally need to be imaged using XCT [73, 74]. In cases where subsurface inspection is required, X-ray radiography is typically used [83, 84] as in [85], who utilised X-ray radiography, macro XRF and infra-red radiation (IRR) techniques to examine the subsurface structure of René Magritte’s Le portrait , finding another partially completed painting beneath the surface.…”

Unraveling the polychromy and antiquity of the Pachacamac Idol, Pacific coast, Peru

“…Single photon processing allows the measurement of energy and coordinates of each X-ray photon collected. A large set of frames is reduced into a 2d histogram processed into higher level data products such as elemental maps for elements of interest [55]. All the XRF spectra were processed with PyMCA software [56].…”

Full field x-ray fluorescence imaging using micro pore optics for planetary surface exploration

“…The X-ray sources are shuttered during read cycles to prevent CCD exposure during readout shifts. A parallel development based on the same design resulted in Cartix, a full-field XRF instrument used in Cultural Heritage research [12].…”