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M.A. Reis

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Jorge Eduardo Fernandez

Università di Bologna

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University of Ljubljana

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University of Ljubljana

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Papers by M.A. Reis

Methodology for a fast determination of EDX Si(Li) detector response function in the 5 keV to 15 keV range

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018

Standard methods used for establishing EDX Si(Li) detectors response functions (DRF) are tedious ... more Standard methods used for establishing EDX Si(Li) detectors response functions (DRF) are tedious and require a significant amount of work and beam time, which is not always available. That fact frequently leads to the disregard of the specific DRF at the time of the measurement, and to the fit of spectra using "general" response functions, which were determined on detectors with different characteristics. The accurate description of the low energy side asymmetry of the peaks is necessary to quantify trace elements accurately and to determine fundamental parameters like X-ray intensity ratios and ionization cross sections. In the present work, a simple method to monitor the energy *Manuscript Click here to view linked References 2 dependence of EDX detectors response function in the 5 keV to 15 keV range is presented. Four PIXE generated X-ray spectra of thin mono-elemental (Ti, Fe, Ni, and Au) films are shown to be enough for this purpose. The methodology can be used as a laboratory-based protocol to establish the DRF and to monitor it over time.

CdTe and EDS HR-PIXE Ta L and M spectra induced by duoplasmatron generated proton and oxygen ion beams

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2017

Particle induced X-ray emission (PIXE) is a powerful technique for quantitative analysis because ... more Particle induced X-ray emission (PIXE) is a powerful technique for quantitative analysis because it is nondestructive, multi-elemental (from Na to U), highly sensitive and requires no special sample preparation. Heavy Ions PIXE (HI-PIXE), may represent a further step in versatility but it comes with added complexity of the physical processes involved in X-ray production, which require among other things new software capabilities. In this work, the specific capacities of the DT2 code are used to simulate and fit Ta Land Mshell spectra obtained during the irradiation of a Ta 2 O 5 thin film deposited upon a polished vitreous graphite substrate, produced in the frame of the Heavy Ions PIXE workpakage of the IAEA Coordinated Research Project F11019 on analytical uses of MeV focused ion beams. Proton and oxygen beams from a duoplasmatron ion source were used, and spectra were collected using both the CdTe and the X-ray Microcalorimeter Spectrometer detectors of the High Resolution High X-ray Energy PIXE (HRHE-PIXE) facility of C 2 TN. Results obtained from the simulation and the fitting of these spectra are presented and discussed.

Holistic RBS-PIXE data reanalysis of SBT thin film samples

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2007

The growth of SrBi2Ta2O9 (SBT) films on top of Pt electrode substrates is an important issue for ... more The growth of SrBi2Ta2O9 (SBT) films on top of Pt electrode substrates is an important issue for the fabrication of ferroelectric based memories. In a recent publication, SBT thin films grown using seeded and unseeded procedures were studied by PIXE and RBS. Difficulties and misfits found in the comparison of results from both techniques were, at that time, overcome by

Use of micro-PIXE in the study of arsenate uptake in lichens and its influence on element distribution and concentrations

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

Micro-PIXE was applied in the study of arsenic metabolism in the lichen Hypogymnia physodes (L.) ... more Micro-PIXE was applied in the study of arsenic metabolism in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were laboratory exposed to a solution of an inorganic arsenic compound arsenate and to a control solution. Perpendicular sections that reveal the morphological properties of the lichen thallus were subjected to microbeam measurements to obtain data on the localization of arsenic and its influence on the distribution and concentrations of the selected macro-and microelements P, S, K, Ca, Cl, Mn, Fe and Zn. Five groups of elements were distinguished regarding losses and redistribution due to arsenic exposure: (1) K and Ca were depleted from all lichen layers; (2) Mn was depleted from the algal layer and lower cortex, (3) Fe was decreased in the algal layer and increased in the lower cortex, (4) Zn was decreased both in the algal layer and the medulla, but increased in the lower cortex, and (5) P and S were decreased in the medulla, but increased in the algal layer and the lower cortex.

High Resolution and Differential PIXE combined with RBS, EBS and AFM analysis of magnesium titanate (MgTiO3) multilayer structures

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010

... In PIXE spectra, on the other hand, Sr K α X-rays are well separated from other contributions... more

Combined application of multielement analysis—k0-INAA and PIXE—and classical techniques for source apportionment in aerosol studies

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006

Three objectives were proposed in this work: (i) to evaluate the concentrations of Air Particulat... more Three objectives were proposed in this work: (i) to evaluate the concentrations of Air Particulate Matter (APM) species obtained via k0-INAA and PIXE by comparison with results obtained via classical methodologies, (ii) to study the water solubility of chloride, sodium, sulfur, potassium and calcium sampled in APM filters and (iii) to analyze the importance of their solubility in the identification of emission sources. The multi-technique analytical approach, using nuclear and classical techniques, not only the results provided for a large number of APM species (essential for source apportionment studies) but also, for several elements, independent methods gave information about their solubility. Results indicated that: (1) the total Cl concentration was lower than the soluble Cl- concentration, showing that it volatilized partially during the PIXE analysis, (2) the majority of Na---provided mainly from sea salt spray---was soluble, (3) in PM10 most of the sulfur was in SO42- chemical form, (4) K exhibited aweaker solubility in the coarse fraction: in PM10-2.5, the insoluble potassium was associated with the mineral aerosol, whereas the soluble fraction resulted from the sea salt spray, (5) Ca showed a lower solubility in the coarse fraction, and the insoluble Ca was associated with a mineral origin.

Diffusion processes in seeded and unseeded SBT thin films with varied stoichiometry

Surface Science, 2006

SrBi 2 Ta 2 O 9 (SBT) is a bismuth layered perovskite (BLP) with interesting ferroelectric proper... more SrBi 2 Ta 2 O 9 (SBT) is a bismuth layered perovskite (BLP) with interesting ferroelectric properties for memories applications. The previous study on the synthesis of seeded and unseeded SBT thin films by the authors [G. González Aguilar, M.E.V. Costa, I.M. Miranda Salvado, J. Eur. Ceram. Soc. 25 (2005) 2331] has shown an increase of the crystallinity of the films and an improvement of the thin film ferroelectric properties when using SBT seeds. However, the detailed role of the seeds as an improver of the thin film properties has not been investigated so far. In the present work we study the role of the seeds, particularly with respect to the reactions between film and (bottom) underlying platinum electrode. The comparison of the results obtained by characterizing the seeded and unseeded thin films via Rutherford backscattering (RBS) and particle induced X-ray emission (PIXE) techniques reveals an effective modification of the substrate-thin film interface by the presence of the seeds. Moreover, the evaluation of the thin film ferroelectric properties by atomic force microscopy (AFM) shows an improvement of the local piezoelectric hysteresis loops by the seeds. These seeding effects as well as those observed in non-stoichiometric SBT thin films with different bismuth contents are used to discuss the barrier-like role of the SBT seeds against reactions between film and the platinum electrode and its contribution to the improvement of the thin film properties.

Reaching for copper pigments speciation with High Resolution Energy Dispersive PIXE

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019

Abstract The C2TN XMS-PIXE system based on a first generation X-ray Microcalorimeter Spectrometer... more Abstract The C2TN XMS-PIXE system based on a first generation X-ray Microcalorimeter Spectrometer (XMS) having 1.5% relative energy resolution at Si K α 1.739 keV and 0.5% relative energy resolution at Fe K α 6.403 keV, became operational in 2008, presaging various developments to emerge from its use and from connected or related but independent advancements by other laboratories. More than ten years having passed since the C2TN XMS-PIXE system first results, knowledge about XMSs use for PIXE has grown meaningfully and new applications are now envisaged and in progress. In the present work, results on the analysis of different copper compounds are presented, and used as an assessment of the capacity of High Resolution Energy Dispersive PIXE (HiRED-PIXE) to provide answers to the problem of copper pigments speciation in Cultural Heritage studies. Related issues of XMS spectra generation and calibration are discussed, as well as first generation systems limitations and its overcome by the use of second and third generation systems.

Air Particulate Matter Characterization of an Industrial Area at North From Lisbon

New and Renewable Technologies for Sustainable Development, 2002

Since 25th January 1999 airborne particulate matter samples have been collected in three stations... more Since 25th January 1999 airborne particulate matter samples have been collected in three stations located at the North outskirts of Lisbon. The samples are analysed by two nuclear analytical techniques: Neutron Activation Analysis (INAA) and Particle Induced X-Ray Emission (PIXE). The multielemental characteristics of the two techniques used (INAA and PIXE) and its complementarity makes it possible to determine concentration for 37 elements. In this work mass concentrations obtained by gravimetry will be compared to the actual legislation and EPA limit values. Results for Lead, Chromium, Copper, Manganese, Nickel, Arsenic, Cadmium, Mercury, Potassium, Antimony, Vanadium and Zinc will be presented and compared in reference values.

Dispersion of chemical elements in an industrial environment studied by biomonitoring using Parmelia sulcata

Journal of Radioanalytical and Nuclear Chemistry, 2000

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Althou... more For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate-heliography-made by Niépce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.

Detection angle resolved PIXE and the equivalent depth concept for thin film characterization

X-Ray Spectrometry, 2005

ABSTRACT The characterization of thin films using PIXE, although basically a simple matter, in pr... more ABSTRACT The characterization of thin films using PIXE, although basically a simple matter, in practice suffers from significant problems. Here two case studies are presented in which the use of grazing detection geometry is shown to be a good solution. The first case study, the analysis of GaSb–InAs films deposited on a GaSb substrate, relates to the measurement of elements of atomic number close to and below that of the substrate. Problems may be due to the tail of the peaks that correspond to x-rays emitted from the substrate, and also to the presence in the substrate of an element having large x-ray emission cross-sections. The use of the simulation capability implemented on the DATTPIXE package is shown to be of good help in the proper planning of the analysis procedure. In the second case study, the distinction between film contamination and substrate material contamination is discussed. In this case the characterization of a ZnO film deposited on sapphire is presented. The concept of equivalent depth is discussed and it is shown to be an important tool for a straightforward distinction between film and bulk contamination. Copyright © 2005 John Wiley &amp; Sons, Ltd.

Influence of traffic on the elemental composition of PM10 and PM2.5 in Oporto region

The aim of this work was to study the influence of traffic emissions on the physical and chemical... more The aim of this work was to study the influence of traffic emissions on the physical and chemical characteristics of PM10 and PM2.5, namely considering: concentration, size distribution and elemental composition. Four monitoring sites in the north of Portugal were selected: two sites directly influenced by traffic emissions and two rural background sites. PM10 and PM2.5 samples were collected using low-volume samplers; the element analyses were performed by particle induced X-ray emission (PIXE). At the sites influenced by traffic emissions PM10 and PM2.5 concentrations were 7-9 and 6-7 times higher than at the background sites. The presence of 17 elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb) was determined in both PM fractions; particle metal contents were 3-44 and 3-27 times higher for PM10 and PM2.5, respectively, than at the backgrounds sites. The results also showed that in coastal areas sea salt sprays are important sources of particles, influenc...

An Assessment of the Response of Tree Bark and Epiphytic Lichens to Elemental Availability at Ground Level Through Nuclear Techniques

Biological monitoring has made quite an impressive way since the early, rather scattered observat... more Biological monitoring has made quite an impressive way since the early, rather scattered observations of environmentally-induced stress on native plants in urban-industrial areas (Nylander, 1866; Arnold, 1901). The heyday really came after World War II though, and, through the following decades, biomonitoring with plants has grown into a serious alternative – or, at least, an useful complement – to traditional (instrumental) methods of assessing contaminants from natural or anthropogenic sources (Burton, 1986; Nimis, 1990). In what concerns air contamination only, such an expansive growth has been sustained mainly by work with lower species – lichens, bryophytes and, to a much lesser extent, nonlichenised fungi. For the last decade, and according to Garty (2000), the number of new references dealing only with lichens in major literature sources has just approached 150. The contribution from higher, vascular plants appears much less relevant. And yet, several genera of those arguably...

Recent developments in G eant 4

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

GEANT4 is a software toolkit for the simulation of the passage of particles through matter. It is... more GEANT4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of GEANT4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.

H + , O 2+ , O 3+ and high resolution PIXE spectra of Yb 2 O 3

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Abstract The number of X-ray spectrometry systems having energy resolution of the order of 10 eV,... more Abstract The number of X-ray spectrometry systems having energy resolution of the order of 10 eV, or less, has increasing recently, included already energy dispersive systems (EDS). Access to previous unseen spectra details and enhanced information including speciation, becomes more common and available. Analysis of high resolution EDS PIXE spectra is, nevertheless a complex task due to the need to carefully account for contributions from minor and satellite transitions. In this work, a pure Yb 2 O 3 sample was irradiated at the HRHE-PIXE setup of C2TN, and simultaneous CdTe and X-ray Microcalorimeter Spectrometer (XMS) spectra were collected. The L-shell spectrum of Yb emitted during irradiations using H + , O 2 + and O 3 + ions in the energy range from 1.0 to 6.5 MeV was studied. Measured L X-ray spectra were analysed taking into account the effects of the multiple ionization in the L and M shells. All spectra were analysed using the DT2 code, which allows to include in the fitting model diagram lines as well as multi-ionization satellites and any other contributions. In this communication we present the results and discuss details and problems related to the transition energies, intensity, line width data, and multiple ionization satellites.

N to K Uranium PIXE spectra obtained at the high resolution high energy PIXE setup

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2014

ABSTRACT The CTN (previous ITN) high resolution high energy (HRHE) PIXE set-up facility was set i... more ABSTRACT The CTN (previous ITN) high resolution high energy (HRHE) PIXE set-up facility was set in operation on July 2008 and upgrades were being implemented until late in 2011. The study of a pure UO2 sample and the mapping of geological sample are the first results where the whole range of possibilities has been exploited, namely the possibility of obtaining simultaneous spectra covering a very wide energy range of more than 100 keV. In this paper, the N-shell to K-shell spectra of Uranium is presented and discussed, as well as the details on the characteristics and capacities of the setup, including the automated X–Y positioning systems installed in the X–Y–Z sample support unit, which allows for the possibility of making macroscopic mappings of geological samples (Chaves et al. (2013) [1]). As for the N-shell lines in the X-ray Microcalorimeter Spectrometer (XMS) spectrum, due to the lack of data (Zschornack (2007) [2]), transition energies were determined using ab initio calculations assuming a closed shell U4+ electronic structure for Uranium prior to the ionisation by proton impact.

Gravimetric and Chemical Features of Airborne PM10 AND PM2.5 in Mainland Portugal

Environmental Monitoring and Assessment, 2005

This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni)... more This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni) and lead (Pb) in PM 10 and PM 2.5 , collected since 1993 by the Technological and Nuclear Institute (ITN) at different locations in mainland Portugal, featuring urban, industrial and rural environments, and a control as well. Most results were obtained in the vicinity of coal-and oil-fired power plants. Airborne mass concentrations were determined by gravimetry. As and Hg concentrations were obtained through instrumental neutron activation analysis (INAA), and Ni and Pb concentrations through proton-induced X-ray emission (PIXE). Comparison with the EU (European Union) and the US EPA (United States Environmental Protection Agency) directives for Ambient Air has been carried out, even though the sampling protocols herein-set within the framework of ITN's R&D projects and/or monitoring contracts-were not consistent with the former regulations. Taking this into account, 1) the EU daily limit for PM 10 was exceeded a few times in all sites except the control, even if the number of times was still inferior to the allowed one; 2) the EU annual mean for PM 10 was exceeded at one site; 3) the EPA daily limit for PM 2.5 was exceeded one time at three sites; 4) the EPA annual mean for PM 2.5 was exceeded at most sites; 5) the inner-Lisboa site approached or exceeded the legislated PMs; 6) Pb levels stayed far below the EU limit value; and 7) concentrations of As, Ni and Hg were also far less than the reference values adopted by EU. In every location, Ni appeared more concentrated in PM 2.5 than in coarser particles, and its levels were not that different from site to site, excluding the control. The highest As and Hg concentrations were found in the neighbourhood of the coal-fired, utility power plants. The results may be viewed as a "worst-case scenario" of atmospheric pollution, since they have been obtained in busy urban-industrial areas and/or near major power-generation and waste-incineration facilities.

Lichen-Transplant Biomonitoring in the Assessment of Dispersion of Atmospheric Trace-Element Pollutants: Effects of Orientation Towards the Wind Direction

Journal of Atmospheric Chemistry, 2004

Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags in a special de... more Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags in a special device allowing a fixed orientation of the lichen towards the wind direction, viz.facing the wind (F orientation) or shielded from the wind by its substrate (T orientation). The F-and T-orientation data were mutually compared and also with reference values (=time zero values of the transplants). The data were analysed via Monte Carlo added target transformation factor analysis (MCATTFA) to get information on possible emission-source profiles and their contributions to total-element levels in transplants, in F-and T-orientations. Both orientations did not differ for Na,

Composition and origin of PM 10 in Cape Verde: Characterization of long-range transport episodes

A receptor modelling study was performed to identify source categories and their contributions to... more A receptor modelling study was performed to identify source categories and their contributions to the PM10 total mass at the Cape Verde archipelago. Trajectory statistical methods were also used to characterize the main atmospheric circulation patterns causing the transport of air masses and to geographically identify the main potential source areas of each PM10 source category. Our findings point out that the variability of the PM10 levels at Cape Verde was prompted by the advections of African mineral dust. The mineral dust load was mainly composed by clay-silicates mineral derived elements (22% of the PM10 total mass on average) with lower amounts of carbonates (9%). A clear northward gradient was observed in carbonates concentration that illustrates the differences in the composition according to the source regions of mineral dust. Mineral dust was frequently linked to industrial emissions from crude oil refineries, fertilizer industries as well as oil and coal power plants, loc...

Methodology for a fast determination of EDX Si(Li) detector response function in the 5 keV to 15 keV range

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018

Standard methods used for establishing EDX Si(Li) detectors response functions (DRF) are tedious ... more Standard methods used for establishing EDX Si(Li) detectors response functions (DRF) are tedious and require a significant amount of work and beam time, which is not always available. That fact frequently leads to the disregard of the specific DRF at the time of the measurement, and to the fit of spectra using "general" response functions, which were determined on detectors with different characteristics. The accurate description of the low energy side asymmetry of the peaks is necessary to quantify trace elements accurately and to determine fundamental parameters like X-ray intensity ratios and ionization cross sections. In the present work, a simple method to monitor the energy *Manuscript Click here to view linked References 2 dependence of EDX detectors response function in the 5 keV to 15 keV range is presented. Four PIXE generated X-ray spectra of thin mono-elemental (Ti, Fe, Ni, and Au) films are shown to be enough for this purpose. The methodology can be used as a laboratory-based protocol to establish the DRF and to monitor it over time.

CdTe and EDS HR-PIXE Ta L and M spectra induced by duoplasmatron generated proton and oxygen ion beams

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2017

Particle induced X-ray emission (PIXE) is a powerful technique for quantitative analysis because ... more Particle induced X-ray emission (PIXE) is a powerful technique for quantitative analysis because it is nondestructive, multi-elemental (from Na to U), highly sensitive and requires no special sample preparation. Heavy Ions PIXE (HI-PIXE), may represent a further step in versatility but it comes with added complexity of the physical processes involved in X-ray production, which require among other things new software capabilities. In this work, the specific capacities of the DT2 code are used to simulate and fit Ta Land Mshell spectra obtained during the irradiation of a Ta 2 O 5 thin film deposited upon a polished vitreous graphite substrate, produced in the frame of the Heavy Ions PIXE workpakage of the IAEA Coordinated Research Project F11019 on analytical uses of MeV focused ion beams. Proton and oxygen beams from a duoplasmatron ion source were used, and spectra were collected using both the CdTe and the X-ray Microcalorimeter Spectrometer detectors of the High Resolution High X-ray Energy PIXE (HRHE-PIXE) facility of C 2 TN. Results obtained from the simulation and the fitting of these spectra are presented and discussed.

Holistic RBS-PIXE data reanalysis of SBT thin film samples

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2007

The growth of SrBi2Ta2O9 (SBT) films on top of Pt electrode substrates is an important issue for ... more The growth of SrBi2Ta2O9 (SBT) films on top of Pt electrode substrates is an important issue for the fabrication of ferroelectric based memories. In a recent publication, SBT thin films grown using seeded and unseeded procedures were studied by PIXE and RBS. Difficulties and misfits found in the comparison of results from both techniques were, at that time, overcome by

Use of micro-PIXE in the study of arsenate uptake in lichens and its influence on element distribution and concentrations

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

Micro-PIXE was applied in the study of arsenic metabolism in the lichen Hypogymnia physodes (L.) ... more Micro-PIXE was applied in the study of arsenic metabolism in the lichen Hypogymnia physodes (L.) Nyl. Lichen thalli were laboratory exposed to a solution of an inorganic arsenic compound arsenate and to a control solution. Perpendicular sections that reveal the morphological properties of the lichen thallus were subjected to microbeam measurements to obtain data on the localization of arsenic and its influence on the distribution and concentrations of the selected macro-and microelements P, S, K, Ca, Cl, Mn, Fe and Zn. Five groups of elements were distinguished regarding losses and redistribution due to arsenic exposure: (1) K and Ca were depleted from all lichen layers; (2) Mn was depleted from the algal layer and lower cortex, (3) Fe was decreased in the algal layer and increased in the lower cortex, (4) Zn was decreased both in the algal layer and the medulla, but increased in the lower cortex, and (5) P and S were decreased in the medulla, but increased in the algal layer and the lower cortex.

High Resolution and Differential PIXE combined with RBS, EBS and AFM analysis of magnesium titanate (MgTiO3) multilayer structures

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010

... In PIXE spectra, on the other hand, Sr K α X-rays are well separated from other contributions... more

Combined application of multielement analysis—k0-INAA and PIXE—and classical techniques for source apportionment in aerosol studies

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006

Three objectives were proposed in this work: (i) to evaluate the concentrations of Air Particulat... more Three objectives were proposed in this work: (i) to evaluate the concentrations of Air Particulate Matter (APM) species obtained via k0-INAA and PIXE by comparison with results obtained via classical methodologies, (ii) to study the water solubility of chloride, sodium, sulfur, potassium and calcium sampled in APM filters and (iii) to analyze the importance of their solubility in the identification of emission sources. The multi-technique analytical approach, using nuclear and classical techniques, not only the results provided for a large number of APM species (essential for source apportionment studies) but also, for several elements, independent methods gave information about their solubility. Results indicated that: (1) the total Cl concentration was lower than the soluble Cl- concentration, showing that it volatilized partially during the PIXE analysis, (2) the majority of Na---provided mainly from sea salt spray---was soluble, (3) in PM10 most of the sulfur was in SO42- chemical form, (4) K exhibited aweaker solubility in the coarse fraction: in PM10-2.5, the insoluble potassium was associated with the mineral aerosol, whereas the soluble fraction resulted from the sea salt spray, (5) Ca showed a lower solubility in the coarse fraction, and the insoluble Ca was associated with a mineral origin.

Diffusion processes in seeded and unseeded SBT thin films with varied stoichiometry

Surface Science, 2006

SrBi 2 Ta 2 O 9 (SBT) is a bismuth layered perovskite (BLP) with interesting ferroelectric proper... more SrBi 2 Ta 2 O 9 (SBT) is a bismuth layered perovskite (BLP) with interesting ferroelectric properties for memories applications. The previous study on the synthesis of seeded and unseeded SBT thin films by the authors [G. González Aguilar, M.E.V. Costa, I.M. Miranda Salvado, J. Eur. Ceram. Soc. 25 (2005) 2331] has shown an increase of the crystallinity of the films and an improvement of the thin film ferroelectric properties when using SBT seeds. However, the detailed role of the seeds as an improver of the thin film properties has not been investigated so far. In the present work we study the role of the seeds, particularly with respect to the reactions between film and (bottom) underlying platinum electrode. The comparison of the results obtained by characterizing the seeded and unseeded thin films via Rutherford backscattering (RBS) and particle induced X-ray emission (PIXE) techniques reveals an effective modification of the substrate-thin film interface by the presence of the seeds. Moreover, the evaluation of the thin film ferroelectric properties by atomic force microscopy (AFM) shows an improvement of the local piezoelectric hysteresis loops by the seeds. These seeding effects as well as those observed in non-stoichiometric SBT thin films with different bismuth contents are used to discuss the barrier-like role of the SBT seeds against reactions between film and the platinum electrode and its contribution to the improvement of the thin film properties.

Reaching for copper pigments speciation with High Resolution Energy Dispersive PIXE

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019

Abstract The C2TN XMS-PIXE system based on a first generation X-ray Microcalorimeter Spectrometer... more Abstract The C2TN XMS-PIXE system based on a first generation X-ray Microcalorimeter Spectrometer (XMS) having 1.5% relative energy resolution at Si K α 1.739 keV and 0.5% relative energy resolution at Fe K α 6.403 keV, became operational in 2008, presaging various developments to emerge from its use and from connected or related but independent advancements by other laboratories. More than ten years having passed since the C2TN XMS-PIXE system first results, knowledge about XMSs use for PIXE has grown meaningfully and new applications are now envisaged and in progress. In the present work, results on the analysis of different copper compounds are presented, and used as an assessment of the capacity of High Resolution Energy Dispersive PIXE (HiRED-PIXE) to provide answers to the problem of copper pigments speciation in Cultural Heritage studies. Related issues of XMS spectra generation and calibration are discussed, as well as first generation systems limitations and its overcome by the use of second and third generation systems.

Air Particulate Matter Characterization of an Industrial Area at North From Lisbon

New and Renewable Technologies for Sustainable Development, 2002

Since 25th January 1999 airborne particulate matter samples have been collected in three stations... more Since 25th January 1999 airborne particulate matter samples have been collected in three stations located at the North outskirts of Lisbon. The samples are analysed by two nuclear analytical techniques: Neutron Activation Analysis (INAA) and Particle Induced X-Ray Emission (PIXE). The multielemental characteristics of the two techniques used (INAA and PIXE) and its complementarity makes it possible to determine concentration for 37 elements. In this work mass concentrations obtained by gravimetry will be compared to the actual legislation and EPA limit values. Results for Lead, Chromium, Copper, Manganese, Nickel, Arsenic, Cadmium, Mercury, Potassium, Antimony, Vanadium and Zinc will be presented and compared in reference values.

Dispersion of chemical elements in an industrial environment studied by biomonitoring using Parmelia sulcata

Journal of Radioanalytical and Nuclear Chemistry, 2000

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Althou... more For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate-heliography-made by Niépce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.

Detection angle resolved PIXE and the equivalent depth concept for thin film characterization

X-Ray Spectrometry, 2005

ABSTRACT The characterization of thin films using PIXE, although basically a simple matter, in pr... more ABSTRACT The characterization of thin films using PIXE, although basically a simple matter, in practice suffers from significant problems. Here two case studies are presented in which the use of grazing detection geometry is shown to be a good solution. The first case study, the analysis of GaSb–InAs films deposited on a GaSb substrate, relates to the measurement of elements of atomic number close to and below that of the substrate. Problems may be due to the tail of the peaks that correspond to x-rays emitted from the substrate, and also to the presence in the substrate of an element having large x-ray emission cross-sections. The use of the simulation capability implemented on the DATTPIXE package is shown to be of good help in the proper planning of the analysis procedure. In the second case study, the distinction between film contamination and substrate material contamination is discussed. In this case the characterization of a ZnO film deposited on sapphire is presented. The concept of equivalent depth is discussed and it is shown to be an important tool for a straightforward distinction between film and bulk contamination. Copyright © 2005 John Wiley &amp; Sons, Ltd.

Influence of traffic on the elemental composition of PM10 and PM2.5 in Oporto region

The aim of this work was to study the influence of traffic emissions on the physical and chemical... more The aim of this work was to study the influence of traffic emissions on the physical and chemical characteristics of PM10 and PM2.5, namely considering: concentration, size distribution and elemental composition. Four monitoring sites in the north of Portugal were selected: two sites directly influenced by traffic emissions and two rural background sites. PM10 and PM2.5 samples were collected using low-volume samplers; the element analyses were performed by particle induced X-ray emission (PIXE). At the sites influenced by traffic emissions PM10 and PM2.5 concentrations were 7-9 and 6-7 times higher than at the background sites. The presence of 17 elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb) was determined in both PM fractions; particle metal contents were 3-44 and 3-27 times higher for PM10 and PM2.5, respectively, than at the backgrounds sites. The results also showed that in coastal areas sea salt sprays are important sources of particles, influenc...

An Assessment of the Response of Tree Bark and Epiphytic Lichens to Elemental Availability at Ground Level Through Nuclear Techniques

Biological monitoring has made quite an impressive way since the early, rather scattered observat... more Biological monitoring has made quite an impressive way since the early, rather scattered observations of environmentally-induced stress on native plants in urban-industrial areas (Nylander, 1866; Arnold, 1901). The heyday really came after World War II though, and, through the following decades, biomonitoring with plants has grown into a serious alternative – or, at least, an useful complement – to traditional (instrumental) methods of assessing contaminants from natural or anthropogenic sources (Burton, 1986; Nimis, 1990). In what concerns air contamination only, such an expansive growth has been sustained mainly by work with lower species – lichens, bryophytes and, to a much lesser extent, nonlichenised fungi. For the last decade, and according to Garty (2000), the number of new references dealing only with lichens in major literature sources has just approached 150. The contribution from higher, vascular plants appears much less relevant. And yet, several genera of those arguably...

Recent developments in G eant 4

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

GEANT4 is a software toolkit for the simulation of the passage of particles through matter. It is... more GEANT4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of GEANT4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.

H + , O 2+ , O 3+ and high resolution PIXE spectra of Yb 2 O 3

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Abstract The number of X-ray spectrometry systems having energy resolution of the order of 10 eV,... more Abstract The number of X-ray spectrometry systems having energy resolution of the order of 10 eV, or less, has increasing recently, included already energy dispersive systems (EDS). Access to previous unseen spectra details and enhanced information including speciation, becomes more common and available. Analysis of high resolution EDS PIXE spectra is, nevertheless a complex task due to the need to carefully account for contributions from minor and satellite transitions. In this work, a pure Yb 2 O 3 sample was irradiated at the HRHE-PIXE setup of C2TN, and simultaneous CdTe and X-ray Microcalorimeter Spectrometer (XMS) spectra were collected. The L-shell spectrum of Yb emitted during irradiations using H + , O 2 + and O 3 + ions in the energy range from 1.0 to 6.5 MeV was studied. Measured L X-ray spectra were analysed taking into account the effects of the multiple ionization in the L and M shells. All spectra were analysed using the DT2 code, which allows to include in the fitting model diagram lines as well as multi-ionization satellites and any other contributions. In this communication we present the results and discuss details and problems related to the transition energies, intensity, line width data, and multiple ionization satellites.

N to K Uranium PIXE spectra obtained at the high resolution high energy PIXE setup

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2014

ABSTRACT The CTN (previous ITN) high resolution high energy (HRHE) PIXE set-up facility was set i... more ABSTRACT The CTN (previous ITN) high resolution high energy (HRHE) PIXE set-up facility was set in operation on July 2008 and upgrades were being implemented until late in 2011. The study of a pure UO2 sample and the mapping of geological sample are the first results where the whole range of possibilities has been exploited, namely the possibility of obtaining simultaneous spectra covering a very wide energy range of more than 100 keV. In this paper, the N-shell to K-shell spectra of Uranium is presented and discussed, as well as the details on the characteristics and capacities of the setup, including the automated X–Y positioning systems installed in the X–Y–Z sample support unit, which allows for the possibility of making macroscopic mappings of geological samples (Chaves et al. (2013) [1]). As for the N-shell lines in the X-ray Microcalorimeter Spectrometer (XMS) spectrum, due to the lack of data (Zschornack (2007) [2]), transition energies were determined using ab initio calculations assuming a closed shell U4+ electronic structure for Uranium prior to the ionisation by proton impact.

Gravimetric and Chemical Features of Airborne PM10 AND PM2.5 in Mainland Portugal

Environmental Monitoring and Assessment, 2005

This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni)... more This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni) and lead (Pb) in PM 10 and PM 2.5 , collected since 1993 by the Technological and Nuclear Institute (ITN) at different locations in mainland Portugal, featuring urban, industrial and rural environments, and a control as well. Most results were obtained in the vicinity of coal-and oil-fired power plants. Airborne mass concentrations were determined by gravimetry. As and Hg concentrations were obtained through instrumental neutron activation analysis (INAA), and Ni and Pb concentrations through proton-induced X-ray emission (PIXE). Comparison with the EU (European Union) and the US EPA (United States Environmental Protection Agency) directives for Ambient Air has been carried out, even though the sampling protocols herein-set within the framework of ITN's R&D projects and/or monitoring contracts-were not consistent with the former regulations. Taking this into account, 1) the EU daily limit for PM 10 was exceeded a few times in all sites except the control, even if the number of times was still inferior to the allowed one; 2) the EU annual mean for PM 10 was exceeded at one site; 3) the EPA daily limit for PM 2.5 was exceeded one time at three sites; 4) the EPA annual mean for PM 2.5 was exceeded at most sites; 5) the inner-Lisboa site approached or exceeded the legislated PMs; 6) Pb levels stayed far below the EU limit value; and 7) concentrations of As, Ni and Hg were also far less than the reference values adopted by EU. In every location, Ni appeared more concentrated in PM 2.5 than in coarser particles, and its levels were not that different from site to site, excluding the control. The highest As and Hg concentrations were found in the neighbourhood of the coal-fired, utility power plants. The results may be viewed as a "worst-case scenario" of atmospheric pollution, since they have been obtained in busy urban-industrial areas and/or near major power-generation and waste-incineration facilities.

Lichen-Transplant Biomonitoring in the Assessment of Dispersion of Atmospheric Trace-Element Pollutants: Effects of Orientation Towards the Wind Direction

Journal of Atmospheric Chemistry, 2004

Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags in a special de... more Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags in a special device allowing a fixed orientation of the lichen towards the wind direction, viz.facing the wind (F orientation) or shielded from the wind by its substrate (T orientation). The F-and T-orientation data were mutually compared and also with reference values (=time zero values of the transplants). The data were analysed via Monte Carlo added target transformation factor analysis (MCATTFA) to get information on possible emission-source profiles and their contributions to total-element levels in transplants, in F-and T-orientations. Both orientations did not differ for Na,

Composition and origin of PM 10 in Cape Verde: Characterization of long-range transport episodes

A receptor modelling study was performed to identify source categories and their contributions to... more A receptor modelling study was performed to identify source categories and their contributions to the PM10 total mass at the Cape Verde archipelago. Trajectory statistical methods were also used to characterize the main atmospheric circulation patterns causing the transport of air masses and to geographically identify the main potential source areas of each PM10 source category. Our findings point out that the variability of the PM10 levels at Cape Verde was prompted by the advections of African mineral dust. The mineral dust load was mainly composed by clay-silicates mineral derived elements (22% of the PM10 total mass on average) with lower amounts of carbonates (9%). A clear northward gradient was observed in carbonates concentration that illustrates the differences in the composition according to the source regions of mineral dust. Mineral dust was frequently linked to industrial emissions from crude oil refineries, fertilizer industries as well as oil and coal power plants, loc...