A simple calibration procedure of polycapillary based portable micro‐XRF spectrometers for reliable quantitative analysis of cultural heritage materials

Abstract

Portable micro-X-ray fluorescence (micro-XRF) spectrometers mostly utilize a polycapillary X-ray lens along the excitation channel to collect, propagate and focus down to few tens of micrometers the X-ray tube radiation. However, the polycapillary X-ray lens increases the complexity of the quantification of micro-XRF data because its transmission efficiency is strongly dependent on the lens specifications and the propagated X-ray energy. This feature results to a significant and not easily predicted modification of the energy distribution of the primary X-ray tube spectrum. In the present work, we propose a simple calibration procedure of the X-ray lens transmission efficiency based on the fundamental parameters approach in XRF analysis. This analytical methodology is best suited for compact commercial and portable micro-XRF spectrometers. The developed calibration procedure is validated through the quantitative analysis of a broad range of samples with archeological relevance such as glasses, historical copper alloys, silver and gold alloys offering an overall accuracy of less than 10%-15%.

Investigations of the Radioactive Presence and Heavy Metallic Materials in Merowe Dam Area

“…In order to detect NORM, 32 soil samples pulverized and packed in 1kg by mass in the cylindrical plastic containers of radius 3 inch and height 3.5 inch, which sits on the (3 inch × 3 inches) high purity germanium (HPGe) detector with geometry the containers are sealed for one week to ensure radioactive equilibrium between the parent radionuclides and their gaseous daughter decay products in the uranium and thorium series [14]. In term of existence heavy metallic elements experiment were carried out by using several devices, Energy Dispersive X ray Fluorescence (EDX8000) fundamental parameters(FP) method to the quantitative analysis were used [15], the first step should supply completely homogeneous and perfectly flat polished surface [16], for any unknown the analysis sensitivity coefficients were calculated by using standard samples, The analytical conditions for ICP-AES were: 1.2 Kw rad frequency power, 10 l/min plasma gas flow rate, 0.6 L/min auxiliary gas flow rate and 0.7 L/min carrier gas flow rate [18].…”

Micro‐XRF analysis of silver decorations on Archaic helmets from Olympia

“…For the quantification of the XRF measurements, the PyMca software (Solé et al . 2007) package was used by introducing as an exciting tube spectrum that deduced from the fitting procedure, described by Kantarelou and Karydas (2016). The precision of the micro‐XRF measurements and validity of the quantitative results was checked by comparison with the results obtained from the analysis of reference Ag alloys (CNR‐91, CNR‐92, CNR‐141 and CNR‐152) cross‐checked by scanning electron microscopy with energy‐dispersive spectroscopy (SEM‐EDS) microanalysis.…”

Investigating the Degradation of Mycenaean Glass Artifacts Using Scientific Methods

“…The INPP micro-XRF spectrometer is composed of an X-ray microfocus Rh anode tube (spot size 50 × 50 µm, maximum high voltage 50 kV, tube current 0.6 mA, 30 W maximum power consumption, beryllium window 0.2 mm thickness) and a polycapillary X-ray lens as a focusing optical element. The X-ray lens provides spatial resolution (spot size) for the filtered exciting beam at the order of ~50 µm CuKα when the exciting beam is filtered [11]. The X-ray detection chain also consists of a thermoelectrically cooled 10 mm 2 silicon drift detector with 146 eV FWHM MnKα and 10 kcps.…”

“…Calibration and precision were made using BAMS005 and Corning A standard reference glasses (Table 1). The spectra were processed with the open software package Pymca for the quantification results [11,12]. The objects were investigated under an LED Dino-Lite microscope, in order to make a first assessment of the corrosion products and identify areas for the subsequent micro-XRF analysis (Table 2).…”