Portable ART Analyser (PART)Development and construction of an innovative and optimised portable XRF instrument for the in situ, non-destructive study of unique and valuable artworks
X-ray fluorescence (XRF) analysis is one of the most widely used analytical techniques for the scientific study of cultural heritage today. Its biggest advantage is the non-destructiveness of the investigation, providing not only qualitative information on the composition of an object but often also (semi-)quantitative information. Recent developments enabled the construction of portable XRF systems of various types, some focussed on flexibility, others on easy mobility. Nevertheless, the analysis of low-Z elements, mostly Na, whose low energy radiation is absorbed in air, is still a problem. Therefore, the development of a XRF-system capable to investigate even those elements was one of the most important issues in the design of the new PART II XRF-instrument.
Several years ago, the first prototype of a vacuum-chamber equipped XRF-instrument was constructed in a cooperation of the Atomic Institute (ATI) of the Vienna University of Technology and the International Atomic Energy Agency (IAEA), Seibersdorf Laboratories. In this instrument the radiation path of both, the excitation and the fluorescence radiation is routed through a vacuum chamber avoiding absorption, and hence improving the detectability of light elements. The excitation radiation is focused on the object only 1-2 mm outside of the vacuum-chamber by passing through a window made of Kapton.
For the construction of the new XRF-system PART II some improvements were realized: The vacuum chamber was optimized in its shape to enable better accessibility to the objects. A bending of the Kapton-window of the vacuum-chamber of the prototype, when the vacuum is applied, could be avoided through better fixation, leading to shorter radiation-paths in air and a lower detection limit of light elements. Modern electronics further lead to an improvement of the detection limits.
The PART II instrument is to be applied in situ at all facilities of the KHM, like the Weltmuseum Wien (WMW), the Theatermuseum (TM), the Kaiserliche Wagenburg Wien, the Schloss Ambras Innsbruck and the new central storage facility at Himberg, and, therefore, has to be mobile. This is implemented by the mounting of the instrument on a stable frame with wheels for transportation. It means that, in spite of the weight of app. 100 kg, the instrument can easily be moved at ground level and can be raised using a lift or a lifting ramp.
The KHM and its affiliated institutions hold extensive collections of highly valuable objects of very different origin, material and shape. Therefore, the PART II instrument has to be very flexible in its application, to meet all the different requirements. Regarding positioning, this is achieved by using three electronically controllable translation stages with high traverse distances. Regarding the materials there are three x-ray tubes available. The anode materials are Cr, Mo and Pd and can be chosen according to the current analytical problem.
So far, the PART II instrument was applied for some selected studies within the project, including objects of many different materials (like glass, enamel, pigments and metals):
- Analysis of the 16th century glass jewellery collection of archduke Ferdinand II of Tyrol, belonging to the Collection of Sculpture and Decorative Arts (Kunstkammer)
- Analysis of a glass cup (Venice around 1500) and other glass objects of the late 16th – mid 17th century, belonging to the Collection of Sculpture and Decorative Arts (Kunstkammer)
- Analysis of the enamel of a Gallo-roman bottle, 2nd century AD of the Collection of Greek and Roman Antiquities
- Pigment analyses on (partly) complex shaped paper-objects of the TM
- Pigment analyses on several paintings of the Picture Gallery
- Analysis on objects of the Collection of Greek and Roman Antiquities, made of clay, lime stone and marble
- Analysis of metal layers, metal parts and glazes of objects of the Collection of Sculpture and Decorative Arts (Kunstkammer)
- Analysis of enamel an metals on coins of the Coin Collection
- Analysis on an 18th century Chinese imperial carved lacquer screen of the WMW and a 17th century Namban Box of the Collection of Sculpture and Decorative Arts (Kunstkammer)
- Analysis for the identification of inorganic pesticides on objects of the WMW
- Investigations according the identification of real purple in manuscripts
Pigment analysis on a small 16th century spinet of the Collection of Historic Musical Instruments
E. Putzgruber, M. Verità, K. Uhlir, B. Frühmann, M. Grießer, G. Krist, “Scientific investigation and study of the sixteenth-century glass jewelry collection of Archduke Ferdinand II”, in 2012 Vienna Congress, The Decorative: Conservation and the Applied Arts, IIC Vienna Congress 10. -14. September 2012, Studies in Conservation 57/1, S217-S226
K. Uhlir, B. Frühmann, G. Buzanich, M. Griesser, C. Streli, P. Wobrauschek, B. Grossmayer, S. Smolek, “A newly developed, portable, vacuum-chamber equipped XRF-instrument, designed for the sophisticated needs of the Kunsthistorisches Museum, Vienna”, in Proceedings XTACH 2011, IOP Conf. Series: Materials Science and Engineering 37 (2012) 012008;
B. Woytek, “Lupa Traiana. Die traianischen Kleinbronzen mit Wölfin: Ein Beitrag zur Münzgeschichte der hohen römischen Prinzipatszeit. Mit einem metallanalytischen Anhang von K. Uhlir und M. Griesser, Naturwissenschaftliche Analysen an vier traianischen Kleinbronzen mit Wölfin”, Numismatische Zeitschrift 119 (2012), 7-30
G. Buzanich, P. Wobrauschek, C. Streli, A. Markowicz, D. Wegrzynek, E. Chinea-Cano, K. Uhlir, M. Griesser, “PART II (Portable ART Analyzer) – development of a XRF spectrometer adapted for the study of artworks in the Kunsthistorisches Museum, Vienna”, X-ray spectrometry 39/2 (2010) 98-102
DI Dr. Martina GRIESSER
Dr. Katharina UHLIR, Dr. Bernadette FRÜHMANN, Dipl.-Rest. Christina Schaaf-Fundneider, in Kooperation mit dem Atominstitut der Österreichischen Universitäten und der Internationalen Atomenergiebehörde (IAEA) – Laboratorien Seibersdorf sowie verschiedenen Sammlungen des KHM
FWF Projekt Nr. L430-N19