Micro‐invasive approach for non‐destructive XRF analysis on light matrix: inside the Opus Lemovicense

Abstract

f Speed, manageability and above all non-destructivity are the main features that make portable X-ray fluorescence (PXRF) a versatile analytical technique widely used in archaeometry. The extensively use of PXRF instruments in recent years during in situ investigations [1][2][3] makes the scientific community wonder how to use in the best way the data collected, as close attention must be paid when analysing non-standard materials such as ancient handcrafted works. Copyright © 2015 John Wiley & Sons, Ltd.Beside, when using energy-dispersive X-ray fluorescence (EDXRF) for the quantitative analysis of low-Z matrix samples, the problem of evaluating self-absorption effects arises, strongly with portable instruments. The elements with Z < 12 are in fact almost undetectable, and the exact matrix composition is in general not known. Different approaches have been proposed and applied in the last decades [4][5][6][7][8]

Optimization of a primary X‐ray filter for X‐ray fluorescence analysis of uranium and plutonium

“…In this study, a Tracer III‐SD handheld XRF spectrometer (Bruker AXS Handheld, Inc., Kennewick, USA) capable of rapid onsite analysis was used. This device is light and convenient to carry, and therefore, it has been widely used for analyzing historical cultural assets, archeological bricks, plants, and architectural stones . Our Tracer III‐SD was equipped with a Ag anode X‐ray tube, a silicon drift detector with energy resolution of 142 eV, and the original primary X‐ray filter consisting of 304.8‐μm (12‐mil) Al, 25.4‐μm (1‐mil) Ti, and 152.4‐μm (6‐mil) Cu (1 mil = 1/1,000 inch [25.4 μm]).…”

Detection limits evaluation of a portable energy dispersive X‐ray fluorescence setup using different filter combinations

“…The ARTAX 200 by Bruker TM makes use of a 12.5 μm Mo foil to filter the output of the Mo target X-ray tube. [12] When the purpose is only to decrease the background in a low-energy region, several possibilities can be made: Cesareo et al [13] filtered the output of a low-power Ag anode X-ray tube with barium oxide powder, while Ferreti et al [14] used a 0.3 mm Cu filter to reduce the bremsstrahlung from a W anode X-ray tube. Most modern systems allow the opportunity to use more than one filter (or composite filters) according to the specificities of the study.…”

“…The use of an aluminum filter is very common in EDXRF. [12,[15][16][17][18][19] It can act as a simple absorption filter owing to the absorption edge at 1.56 keV and also absorbs L lines from the X-ray tube (normally Ag, Rh or Mo) as a consequence of the high-mass absorption coefficient for these energies. The absence of the L lines from the tube removes their spectral interference.…”

“…These kinds of filters take its benefit from the fact that an element has a low‐mass absorption coefficient for its own characteristic lines, as these lines lie immediately below the absorption edge jump. The ARTAX 200 by Bruker TM makes use of a 12.5 µm Mo foil to filter the output of the Mo target X‐ray tube …”