Elemental 2D imaging of paintings with a mobile EDXRF system

Abstract

Imaging techniques are now used commonly and intensively in cultural heritage object analysis. Nowadays, many different techniques in nature as well as many applications exist, where they can be applied. X-ray radiography and infrared reflectography as well as UV photography are some of the most applied techniques. The study of works of art usually requires these techniques to be non-invasive. Furthermore, they are frequently required to perform in situ analysis. A few years ago, our laboratory developed a mobile energy-dispersive X-ray fluorescence and UV-vis-NIR coupled spectrometer, especially designed for fieldwork studies, where all three techniques can be applied strictly at the same site of analysis. Recent developments on a new positioning system have now allowed us to perform 2D elemental mappings with our equipment, which is especially well adapted to painting analysis. The system control is carried out entirely through a laptop computer running a dedicated homemade software. The positioning is achieved by means of a CCD camera embedded in the system and controlled via a Wi-Fi connection through the computer. The data acquisition system, which is made through a homemade multichannel pulse height analyzer, being also managed via the software mentioned above, goes through an Ethernet connection. We will present here the new developments of the system and an example of in situ 2D elemental mapping applied on an anonymous oil painting on wood panel. The discovery of a hidden painting under this oil painting makes it a good choice for a first example of 2D large scan with a mobile instrument.

Discovery of a woman portrait behind La Violoniste by Kees van Dongen through hyperspectral imaging

“…To do that, we used a homemade XRF system, made of a Moxtek Magnum X-ray tube (50 kV) (with a Ag anode), a detector X-123SDD Amptek (25 mm 2 ), with a resolution of 130 eV at 5.9 keV. The scan step was 1.4 mm (2 s/point), with a tension of 35 kV and a courant of 130 µA [11][12][13]. The software used for the XRF results processing is PyMca [14].…”

Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

“…Scanning micro-XRF (mXRF) with a resolution in the micrometer range is an long established technique in the investigation of cultural heritage objects, but the construction of scanners for macroscopic objects is technically challenging [88]. Since the beginning of the 1990s several instruments have been described and their value demonstrated in case studies [89][90][91][92][93]. Also a commercially available system, the "Artax" (Röntec GmbH, Berlin, now Bruker Nano GmbH, Berlin, Germany) was presented and used in several case studies [94,95].…”

Examination of historical paintings by state-of-the-art hyperspectral imaging methods: from scanning infra-red spectroscopy to computed X-ray laminography

“…A self-portrait by Australian artist Sir Arthur Streeton (1867-1943) that he covered at a later stage with heavy brushstrokes of lead white paint has been re-visualized by Howard et al [15] at the Australian Synchrotron radiation facility, making use of a multiple element detector system offering very fast scanning possibilities. One of the developments permitting the use of the MA-XRF method on a larger scale has been the construction of mobile (i.e., X-ray tube based) MA-XRF scanners [14,[16][17][18] that can be used inside the museum or picture gallery where the works of art normally are displayed or conserved. Alfeld et al [18] has designed and optimized such a device, reporting element sensitivities that are of same order of magnitude as those of the SR-based setup employed to scan Patch of Grass.…”