Type: (Multi/Hyper Spectral) Imaging

Overview

MOLAB offers access to two scanning X-ray fluorescence (XRF) systems for micro and macro multi-element mapping of surfaces in a non-invasive manner. Elemental distribution maps at different spatial scales are of great interest for heritage science applications and particularly in the examination of paints and inks in ancient paintings and historical documents.

X-rays are highly penetrating and generally allow to non-destructively probe the entire painting stratigraphy. Hence the registration of elemental maps in a wide atomic number range (Z>12) allows for the investigation of the pigment use by the artist and for studying the historical evolution of the paint, also revealing hidden paint layersin the case of pentimenti, retouchings and over-paintings etc.

Here follows a brief description of the scanning XRF instrumentation available in the MOLAB platform.

Technical details

The µXRF scanning system ARTAX400 (Bruker) is equipped with a low-power metal-ceramic-type X-ray tube with a Mo anode as the excitation source operating at 50 kV and 700 µA. The system is provided with a Peltier-cooled silicon drift detector (SDD) with an active area of 10 mm2 and a Be window (energy resolution<155 eV at MnKα). The X-ray beam is collimated on the surface with a spot diameter of 650 µm. The distance between the sample and the spectrometer is controlled via a laser diode and is set at 10 mm to allow the analysis of uneven surfaces.  A CCD camera provides a magnified image of the sample region under investigation and allows accurate selection of the measurement position. The measuring head is mounted on a remote-controlled X-Y-Z stage which enables to execute high spatial resolution line-scan and area mapping providing multi-element analyses on areas with maximum dimensions of 50×50mm2. Element distributions across the sample are then originated by dedicated software.

Providers

MOLAB Italy: Labdia