Particle-induced Gamma-ray Emission Research Articles

Study of atmospheric aerosols by IBA techniques: The LABEC experience

Abstract At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN (Florence, Italy) an external beam facility is fully dedicated to PIXE-PIGE measurements of the elemental composition of atmospheric aerosols. All the elements with Z > 10 are simultaneously detected by PIXE typically in one minute. This setup allows us an easy automatic positioning, changing and scanning of samples collected by different kinds of devices: long series of daily PM (Particulate Matter) samples can be analysed in short times, as well as size-segregated and high time-resolution aerosol samples. Thanks to the capability of detecting all the crustal elements, PIXE-PIGE analyses are unrivalled in the study of mineral dust: consequently, they are very effective in the study of natural aerosols, like, for example, Saharan dust intrusions. Among the detectable elements there are also important markers of anthropogenic sources, which allow effective source apportionment studies in polluted urban environments using a multivariate method like Positive Matrix Factorization (PMF). Examples regarding recent monitoring campaigns, performed in urban and remote areas, both daily and with high time resolution (hourly samples), as well as with size selection, are presented. The importance of the combined use of the Particle Induced Gamma Ray emission technique (PIGE) and of other complementary (non-nuclear) techniques is highlighted.

Closing the Mass Balance on Fluorine on Papers and Textiles.

Papers and textiles that are treated with per- and polyfluoroalkyl substances (PFASs) are sources of human and environmental exposure. Data for individual PFASs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), are not placed into the context of total fluorine for papers and textiles. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to quantify volatile and ionic PFASs, respectively, and the total oxidizable precursor (TOP) assay was used to quantify precursors that form perfluoroalkyl carboxylates. Molar sums of PFASs obtained by GC-MS, LC-MS/MS, and precursors were compared to total fluorine (nmol F/cm2) determined by particle-induced gamma ray emission (PIGE) spectroscopy, measured before and after extraction. Volatile and ionic PFASs and unknown precursors accounted for 0-2.2%, 0-0.41%, and 0.021-14%, respectively, of the total nmol F/cm2 determined by PIGE. After extraction, papers and textiles retained 64 ± 28% to 110 ± 30% of the original nmol F/cm2 as determined by PIGE, indicating that the majority of fluorine remains associated with the papers and textiles. The sum of PFASs in the volatile, ionic, and precursor fraction, and total fluorine after extraction indicate that mass balance was achieved (within analytical error) of the initial total fluorine measured by PIGE.

PIGE as a screening tool for Per- and polyfluorinated substances in papers and textiles

Per- and polyfluoroalkyl substances (PFASs) comprise a large array of man-made fluorinated chemicals. It is an emerging chemical class of concern because many PFASs are environmentally persistent and some have known ecological and human toxicity. Consumer products treated with PFASs result in human exposure to PFASs through inhalation, ingestion, and environmental exposure to emissions from wastewater or from landfills. A rapid screening method based on total fluorine was developed and applied to quantify PFASs on consumer papers and textiles. Particle-Induced Gamma Ray Emission (PIGE) spectroscopy provides a non-destructive and quantitative measurement of total fluorine on papers and textiles. This technique is both rapid and sensitive, with a limit of detection (LOD) of 13nmolF/cm2 for papers and 24–45nmolF/cm2 for textiles, with reproducibility of ±12% RSD for both. PIGE is a high throughput (>20samples/hr typically) method that was applied to 50 papers and 50 textiles in commerce to demonstrate the method.

Simultaneous determination of low Z elements in barium borosilicate glass samples by in situ current normalized particle induced gamma-ray emission methods

Particle induced gamma-ray emission (PIGE) method using 4 MeV proton beam was utilized to analyze two types of barium borosilicate glass (BaBSG) samples for quantification of concentrations of low Z elements. The in situ current normalization method was applied in the analysis of eight samples containing varying concentration of F along with Si, B and Na. Charge normalized PIGE method was applied to determine concentrations of above low Z elements including Li and Al in samples having simulated nuclear waste from reprocessing of thoria spent fuel. Synthetic samples and NIST SRMs were used for method validation.

Measurement of gamma-ray production cross sections in Li and F induced by protons from 810 to 3700 keV

Differential cross sections for the reaction channels 7Li(p,nγ1-0)7Be (Eγ=429keV), 7Li(p,pγ1-0) (Eγ=478keV), 19F(p,pγ1-0)19F (Eγ=110keV), 19F(p,pγ2-0)19F (Eγ=197keV) have been measured in the proton energy range 810–3700keV, with an energy step of 10keV. The reactions channels 19F(p,pγ3-1)19F (Eγ=1236keV), 19F(p,pγ4-1)19F (Eγ=1349keV), 19F(p,pγ5-2)19F (Eγ=1357keV) have also been investigated in the proton energy range 1915–3225keV. The experimental set-up, the uncertainty budget, the comparison with other data and the progress assured by new data in the analytical use of standard-less Particle Induced Gamma-ray Emission (PIGE) are discussed.

Lithium distribution analysis in all-solid-state lithium battery using microbeam particle-induced X-ray emission and particle-induced gamma-ray emission techniques

For confirming the feasibility of micrometer scale analysis of lithium distribution in the all-solid-state lithium battery using a sulfide-based solid electrolyte, the cross-section of pellet type battery was analyzed by microbeam particle-induced X-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) measurements. A three-layered pellet-type battery (cathode: LiNbO3-coated [Formula: see text]/solid electrolyte: [Formula: see text]/anode: [Formula: see text]) was prepared for the measurements. Via elemental mapping of the cross-section of the prepared battery, the difference in the yields of gamma rays from the [Formula: see text] inelastic scattering (i.e., the lithium concentrations) between the composite electrodes and the solid electrolyte layer was clarified. The difference in the number of lithium ions at the composite anode/solid electrolyte interface of ([Formula: see text] mol) in the battery can be clearly detected by the microbeam PIGE technique. Therefore, lithium distribution analysis with a micrometer-scale spatial resolution is demonstrated. Further analysis of the cathode/anode composite electrodes with the different states of charge could provide important information to design a composite for high-performance all-solid-state lithium batteries.

Ion beam analysis of elemental signatures in uranium dioxide samples: importance for nuclear forensics

In this paper the suitability of two non-destructive analytical techniques for identification of elemental signatures in samples containing uranium of different enrichments was studied. The measurements were based on particle induced X-ray emission (PIXE) and particle induced gamma-ray emission (PIGE) methods. The samples were irradiated by 3 and 5 MeV protons at the 3 MV Tandetron™ of Horia Hulubei National Institute for Physics and Nuclear Engineering. The characteristic X and gamma rays were measured using high purity germanium (HPGe) detectors. The GUPIX software was applied for processing the PIXE spectra, while a relative standardization was applied for PIGE analysis by using certified comparator standards and proton stopping powers calculated by SRIM.

Determination of trace concentration of aluminium in raw rice samples using instrumental neutron activation analysis and particle induced gamma-ray emission methods

Determination of aluminium concentration in food samples is important for the food safety and quality control purpose owing to its toxicity. This work demonstrates determination of aluminum concentrations in raw rice samples, obtained from agricultural field, by instrumental neutron activation analysis (INAA) using reactor neutrons and high resolution gamma-ray spectrometry. Particle induced gamma-ray emission (PIGE) method was also standardized for the determination of aluminium content in some samples. The aluminium contents were found to be in the range of 5–80 mg kg−1. INAA and PIGE methods were validated by analyzing five reference materials obtained from NIST and IAEA.

Chemical composition characterization of ancient glass finds from Troesmis—Turcoaia, Romania

This paper reports and discusses the chemical composition of 20 glass fragments discovered during the 2012 archeological survey at Troesmis (Turcoaia, Tulcea county, Romania) and dated to the Roman and the Byzantine/Early Medieval periods. The data were obtained by two external Ion beam analysis (IBA) methods—namely Particle-induced X-ray emission (PIXE) and Particle-induced gamma-ray emission (PIGE)—and they were compared to the recognized compositional glass groups from the Mediterranean region during the first millennium AD. The Troesmis assemblage turned out to contain samples belonging to several distinct categories of ancient glass, obtained from different raw materials and manufacturing procedures. Some of the analyzed vitreous finds from Troesmis were the result of glass recycling, while others were identified as deriving from Roman glass vessels imported from the Levantine or Egyptian shores of the Mediterranean. This archeometric study brings additional arguments for the long-range commercial exchanges during the Roman period.

Chemical analysis of archaeological clay potteries by PIGE and PIXE methods using proton beams from tandem accelerator for provenance study

Particle induced gamma-ray emission (PIGE) and particle induced X-ray emission (PIXE) methods using proton beams from tandem accelerator were applied for chemical analysis of sixteen archaeological clay potteries. The samples were characterized by Fourier transform infrared spectroscopy to obtain firing temperature. PIGE method was used for determination of concentrations of Si and Al and PIXE was used to determine concentrations of eight transition elements. Concentration ratios of SiO2 to Al2O3 and statistical cluster analysis using transition elemental concentrations of samples indicated two major groups. PIGE and PIXE methods were validated by analyzing reference materials from IAEA and NIST.

Quantitative investigation of physical factors contributing to gold nanoparticle-mediated proton dose enhancement

Some investigators have shown tumor cell killing enhancement in vitro and tumor regression in mice associated with the loading of gold nanoparticles (GNPs) before proton treatments. Several Monte Carlo (MC) investigations have also demonstrated GNP-mediated proton dose enhancement. However, further studies need to be done to quantify the individual physical factors that contribute to the dose enhancement or cell-kill enhancement (or radiosensitization). Thus, the current study investigated the contributions of particle-induced x-ray emission (PIXE), particle-induced gamma-ray emission (PIGE), Auger and secondary electrons, and activation products towards the total dose enhancement. Specifically, GNP-mediated dose enhancement was measured using strips of radiochromic film that were inserted into vials of cylindrical GNPs, i.e. gold nanorods (GNRs), dispersed in a saline solution (0.3 mg of GNRs/g or 0.03% of GNRs by weight), as well as vials containing water only, before proton irradiation. MC simulations were also performed with the tool for particle simulation code using the film measurement setup. Additionally, a high-purity germanium detector system was used to measure the photon spectrum originating from activation products created from the interaction of protons and spherical GNPs present in a saline solution (20 mg of GNPs/g or 2% of GNPs by weight). The dose enhancement due to PIXE/PIGE recorded on the films in the GNR-loaded saline solution was less than the experimental uncertainty of the film dosimetry (<2%). MC simulations showed highly localized dose enhancement (up to a factor 17) in the immediate vicinity (<100 nm) of GNRs, compared with hypothetical water nanorods (WNRs), mostly due to GNR-originated Auger/secondary electrons; however, the average dose enhancement over the entire GNR-loaded vial was found to be minimal (0.1%). The dose enhancement due to the activation products from GNPs was minimal (<0.1%) as well. In conclusion, under the currently investigated conditions that are considered clinically relevant, PIXE, PIGE, and activation products contribute minimally to GNP/GNR-mediated proton dose enhancement, whereas Auger/secondary electrons contribute significantly but only at short distances (<100 nm) from GNPs/GNRs.

Improvements in the PIGE technique via gamma-ray angular distribution

Particle induced gamma-ray emission (PIGE) is an ion beam technique used for isotopic elemental analysis of materials, based on gamma-ray spectroscopy. In the traditional PIGE setup, the gamma-ray detector is positioned at the neutral angles 55° or 125° with respect to the beam direction in order to measure gamma-rays with different angular distributions. Although these angles permit measurements without an a-priori knowledge of the specific angular distributions, this choice is not efficient if one wants to identify a specific element since a longer acquisition time is needed.In this work, we propose to optimize the PIGE measurements by choosing the detector angle position due to the previous knowledge of the gamma-ray multipolarity and the nuclear reaction. We present the angular distribution calculations for the isotopes most frequently identified by PIGE analysis, specially in Cultural Heritage objects. Calculations demonstrate that a gain in the intensity up to 70% can be achieved allowing the elemental identification in shorter times. This result is promising and represents a more efficient alternative to perform PIGE measurements.

In-situ measurement of the lithium distribution in Li-ion batteries using micro-IBA techniques

Direct observation of lithium concentration distribution in lithium-ion battery composite electrodes has been performed for the first time. Lithium-ion battery model cells for particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) measurements were designed and fabricated. Two dimensional images of lithium concentration in LiFePO4 composite electrodes were obtained with PIXE and PIGE by scanning the proton microbeam for various charged states of the electrodes. Lithium concentration in LiFePO4 composite electrodes was decreased from the contact interface between LiFePO4 electrode and liquid electrolyte during the charge reaction.

Development of a Reference Database for Particle-Induced Gamma-ray Emission spectroscopy

Particle-Induced Gamma-ray Emission (PIGE) is a powerful analytical technique that exploits the interactions of rapid charged particles with nuclei located near a sample surface to determine the composition and structure of the surface regions of solids by measurement of characteristic prompt γ rays. The potential for depth profiling of this technique has long been recognized, however, the implementation has been limited owing to insufficient knowledge of the physical data and lack of suitable user-friendly computer codes for the applications. Although a considerable body of published data exists in the nuclear physics literature for nuclear reaction cross sections with γ rays in the exit channel, there is no up-to-date, comprehensive compilation specifically dedicated to IBA applications. A number of PIGE cross-section data had already been uploaded to the Ion Beam Analysis Nuclear Data Library (IBANDL) (http://www-nds.iaea.org/ibandl) by members of the IBA community by 2011, however a preliminary survey of this body of unevaluated experimental data has revealed numerous discrepancies beyond the uncertainty limits reported by the authors. Using the resources and coordination provided by the IAEA, a concerted effort to improve the situation was made within the Coordinated Research Project on the Development of a Reference Database for PIGE spectroscopy, from 2011 to 2015. The aim of the CRP was to create a data library for Ion Beam Analysis that contains reliable and usable data on charged particle γ-ray emission cross sections that would be made freely available to the user community. As the CRP has reached its completion, we shall present its main achievements, including the results of nuclear cross-section evaluations and the development of a computer code that will become available to the public allowing for the implementation of a standardless PIGE technique.

Study of In distribution on GaInSb:Al crystals by ion beam techniques

III–V ternary alloys semiconductor materials, in particular Ga1−xInxSb, are ideal candidates for device substrates because of the possibility to define the lattice constant as a function of the third element, indium. Aluminum, an isoelectric dopant for Ga and In, increases the carrier mobility in GaSb crystals and has influence over the concentration of native defects by passivating and/or compensating them. To understand the influence of Al on the distribution of indium in ternary alloys of Ga0.8In0.2Sb, pure and doped ingots were obtained with approximately 1020atoms/cm3 of Al using a vertical Bridgman system. Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) were used to obtain information on the structure defects and chemical composition of the crystals.The doped ingots showed good structural homogeneity when compared with the undoped alloy, and they were free from cracks and micro cracks. All of the obtained ingots present precipitates, twins and grains with different concentrations of In.The small compositional variation observed in the doped ingots along the radial direction (measured by PIXE), may be related to the solid–liquid interface’s quasi-equilibrium behavior. Regarding to the growth direction, it was observed that the undoped ingots exhibit a higher segregation phenomenon of the third element than the doped ingots.The obtained results indicate that aluminum influences the indium distribution in the ingots, thus ternary ingots with more homogeneous composition can be obtained and consequently electrical properties improved.

Structural and waveguiding characteristics of Er3+:Yb3Al5−yGayO12 films grown by the liquid phase epitaxy

Erbium (Er3+) doped ytterbium garnet (Er:Yb3Al5−yGayO12; y=0, 0.55 and 1.1) single crystalline thick films have been grown by the low-temperature liquid phase epitaxy method (LPE). The composition of the films was determined using the high resolution XRD, the particle-induced X-ray emission spectroscopy (PIXE) and the particle-induced gamma-ray emission spectroscopy (PIGE). The lattice mismatch between films and substrates was investigated by the high-resolution X-ray diffraction. The surface analysis was carried out by the atomic force microscopy (AFM). Pure infrared emission of Er3+ ions was observed in all films containing gallium. The characteristics such as refractive index, thickness and light propagation were studied by the m-line spectroscopy (MLS) using several wavelengths (633, 964, 1311 and 1552nm). All samples, where y=1.1, were multimode waveguides. For these reasons, the Er:Yb3Al3.9Ga1.1O12 seems to be a promising material for light amplifiers in the IR region.

Boron analysis for neutron capture therapy using particle-induced gamma-ray emission

The neutron source of BNCT is currently changing from reactor to accelerator, but peripheral facilities such as a dose-planning system and blood boron analysis have still not been established. To evaluate the potential application of particle-induced gamma-ray emission (PIGE) for boron measurement in clinical boron neutron capture therapy, boronophenylalanine dissolved within a cell culture medium was measured using PIGE. PIGE detected 18μgB/mL f-BPA in the culture medium, and all measurements of any given sample were taken within 20min. Two hours of f-BPA exposure was required to create a boron distribution image. However, even though boron remained in the cells, the boron on the cell membrane could not be distinguished from the boron in the cytoplasm.

Analysis of Medieval and Post‐Medieval Glass Fragments from the Dubrovnik Region (Croatia)

Dubrovnik was an important trade city throughout the medieval and post‐medieval time period, maintaining its own glass production from the 14th to the 16th century. Unfortunately, Dubrovnik glass discoveries have not been well investigated up until now, except via archival data in large data analyses. In the following work, we will shed new light on the glass material found in this region, which has diverse origins, chronology, typology and style. Medieval and post‐medieval glass finds (10th/12th–18th centuries) discovered during archaeological excavations in Dubrovnik and the Dubrovnik region were analysed using particle‐induced X‐ray emission (PIXE) and particle‐induced gamma‐ray emission (PIGE), which revealed three main compositional groups: natron glass, plant‐ash glass and potash glass. This demonstrates the important commercial links present between Dubrovnik and other major glass‐making centres.

Large areas elemental mapping by ion beam analysis techniques

The external beam line of the Laboratory for Material Analysis with Ion Beams (LAMFI) is a versatile setup for multi-technique analysis. X-ray detectors for Particle Induced X-rays Emission (PIXE) measurements, a Gamma-ray detector for Particle Induced Gamma- ray Emission (PIGE), and a particle detector for scattering analysis, such as Rutherford Backscattering Spectrometry (RBS), were already installed. In this work, we present some results, using a large (60-cm range) XYZ computer controlled sample positioning system, completely developed and build in our laboratory. The XYZ stage was installed at the external beam line and its high spacial resolution (better than 5 μm over the full range) enables positioning the sample with high accuracy and high reproducibility. The combination of a sub-millimeter beam with the large range XYZ robotic stage is being used to produce elemental maps of large areas in samples like paintings, ceramics, stones, fossils, and all sort of samples. Due to its particular characteristics, this is a unique device in the sense of multi-technique analysis of large areas. With the continuous development of the external beam line at LAMFI, coupled to the robotic XYZ stage, it is becoming a robust and reliable option for regular analysis of trace elements (Z > 5) competing with the traditional in-vacuum ion-beam-analysis with the advantage of automatic rastering.

PIXE–PIGE analyses of Byzantine glass bracelets (10th–13th centuries AD) from Isaccea, Romania

This paper reports the particle induced X-ray emission (PIXE) and particle induced gamma-ray emission (PIGE) analyses of 78 glass bracelet fragments discovered in the Byzantine fortified settlement of Isaccea, Romania (10th–13th centuries AD). The chemical composition of the glass was used to identify the raw materials and manufacturing techniques. Most of the bracelets turned out to be soda-lime-silica glasses, but lead and soda-lime-lead glasses were also identified. The PIXE–PIGE data revealed the glass chromophores and provided clues about the pigments used to decorate the external surfaces of some bracelets—lead stannate and gold alloy. The analytical results showed that the bracelets were manufactured by recycling different types of coloured glass, probably in a local workshop.