Mapping with Macro X-ray Fluorescence Scanning of Raffaello's Portrait of Leo X

Raffaello is renowned as one of the Old Renaissance Masters and his paintings and painting technique are famous for the details and naturality of the characters. Raffaello is famous in particular for the then-new technique of oil painting, which he mastered and perfected. On the occasion of the 500th anniversary of the death of Raffaello (2020), there was a large exhibition at the Scuderie del Quirinale in Rome, where many paintings and drawings by the Old Master were on show. One of these paintings was the portrait of Leo X with two cardinals belonging to the collection of the Uffizi galleries in Florence. Before going to Rome, the painting underwent conservation treatments at the Opificio delle Pietre Dure, where a comprehensive diagnostic campaign was carried out with the aim of understanding the painting materials and technique of the Old Master. In this paper, the results of macro X-ray fluorescence (MA-XRF) analysis, carried out exploiting the instrument developed by INFN-CHNet, are shown. Among the results, "bismuth black" and the likely use of glass powders in lakes are discussed

The Role of PIXE and XRF in Heritage Science: The INFN-CHNet LABEC Experience

Analytical techniques play a fundamental role in heritage science. Among them, Particle Induced X-ray Emission (PIXE) and X-ray Fluorescence (XRF) techniques are widely used in many laboratories for elemental composition analysis. Although they are well-established, a strong effort is put on their upgrade, making them suitable for more and more applications. Over the years, at the INFN-LABEC (the laboratory of nuclear techniques for the environment and cultural heritage of the Italian National Institute of Nuclear Physics), the INFN-CHNet group, the network devoted to cultural heritage, has carried out many technological improvements to the PIXE and XRF set-ups for the analysis of works of art and archaeological finds. Among the many, we recall here the scanning external microbeam facility at the TANDEM accelerator and the MA-XRF scanner. The two instruments have shown complementary features: the former permits quantitative analysis of elements heavier than sodium, which is not possible with the latter in most of the case studies. On the contrary, the scanner has the undeniable advantage of portability, allowing it to work in situ. In this framework of technological developments in heritage science, INFN, CERN, and OPD are jointly carrying on the MACHINA (Movable Accelerator for Cultural Heritage In-situ Non-destructive Analysis) project for on-site Ion Beam Analysis (IBA) studies on cultural heritage

A new scanner for in-situ digital radiography of paintings

X-ray radiography is one of the most widely used imaging techniques in the field of Cultural Heritage, both for conservation and investigation purposes. Performing radiographies in museums, thus avoiding movements of works of art, has been recently made easy by digital acquisition of images, but when the whole scan of a large painting is required, technical solutions for a portable device are still not at hand. The inherent weight of the X-ray tube, including protection shields, and of the high voltage generator makes the design of a “portable” device very difficult. In this project the solution of the puzzle was separating devices devoted to different tasks, in order to maintain each item under 50 kg weight, thus being transportable with minimum effort. The proper RX scanner is composed of two independent frames (Fig.1) in aluminium, carrying and moving the X-ray tube and the digital detector. For both units, a couple of DC servomotors (G5© by Omron Electronics Ltd, UK) are driving the movements on X and Y axis. A third frame is added, to support the painting. The distance between the two units is usually set at 1 m and the work of art is located as close as possible to the detector, to minimize magnification and penumbra effects. Both units may be moved or installed on a scaffold, to scan wider paintings. Levelling of the frames and alignment of X-ray beam with detector is performed by setting the levelling feet, collimating the beam with a small pinhole. Once aligned the units, the scan is automatically performed by remote control of motion, on horizontal and vertical axis, by dedicated software (NS-Runtime© rel.1.2 by Omron Co.). X-ray tube and detector move simultaneously and stop at the foreseen position for image acquisition. X-ray shot and digital acquisition follow, then the following position is reached. The scan is tailored to each painting, and the digital images are automatically stitched at the end of the scan. For instance, a painting of size 1 x 1 m2 requires 144 shots and about 3-hour scan. The stitching is a matter of few minutes. The X-ray tube is a Varian M-143T with tungsten anode, maximum anode voltage 49 kV, air cooled. The detector is a Teledyne DALSA (Canada) RadEye200, a two dimensional CMOS photodiode array combined with a Gd2O2S scintillator screen. It is composed of 1024 x 1000 pixel, of side length 96 µm. Depth of digitization is 12 bit/pixel. The scanning system has been designed, realized and tested. It has proved to recover each position in the scan within one pixel width and to be stable during all acquisitions

Radiation shielding of spacecrafts in interplanetary flights

Published by SIS-Pubblicazioni - Laboratori Nazionali di FrascatiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal