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Abstract Quantitative analysis of materials from Heavy Ion PIXE spectra remains impeded by the lack of reliable X-ray production cross section (XPCS) data. Although efforts at experimental Heavy Ion induced XPCS measurements still continue, Multiple Ionisation (MI) effects, which are not fully described by theory, render simulations of heavy ion PIXE data unreliable for large Z1/Z2 collisions, especially at low energies. This is also exacerbated by the random selection of projectile-target combinations for measured and reported experimental data available to validate theory. This study explored heavy ion induced X-ray production cross section deviations from those induced by protons at the same ion velocity. This enabled evaluations of the degree to which cross sections are enhanced through MI effects, with the aim of predicting XPCS due to heavy ion impact. The evaluation was carried out through the scaling of experimental heavy ion to theoretical proton cross section ratios (R), which were then used for the interpolation of XPCS in the same target element for ‘missing’ projectiles within the range of evaluation. Here we present measurements of heavy ion induced total L-shell XPCS in Bi, carried out to determine HI/p MI induced deviations due to C, F, Cl and Ti projectiles at an ion velocity range of (0.2–1.0) MeV/nucleon.

Understanding the interaction between the fusion plasma and the plasma-facing materials (PFMs) is crucial for achieving the optimal performance, safety, and lifetime of the fusion devices. Relevant materials have been intensely studied to determine fuel retention and the composition of the co-deposited layers on the PFMs by depth profile analysis using Laser-Induced Breakdown Spectroscopy (LIBS) and Calibration-Free (CF)-LIBS. However, the comparison between the layers containing a mixture of different (seeding) gases using LIBS, has not been studied systematically. Consequently, the aim of this work is the LIBS depth profile analysis of Be-based samples containing the fuel (D) and one of the seeding gases (N, Ne, He) with variable concentrations to study the potential impact on fuel retention in the PFMs. The LIBS measurements were performed using Nd:YAG laser (1064 nm) under Ar atmosphere (at 2 and 100 mbar). In LIBS the ablation rate was evaluated, spectral lines of all relevant elements except N and Ne were detected and compared with the SIMS depth profiles. The reasons for the non-detectability of Ne are discussed in detail.

A detailed assessment of the thermo-mechanical limits of the International Tokamak Experimental Reactor (ITER) divertor with respect to potential excessive local transient heat loads due to edge localised modes (ELMs) has revealed a particular power loading scenario arising from the fact that ELM ions expelled from the upstream pedestal region will arrive at the divertor target plates without substantial thermalisation. As a consequence of their Larmor gyration around magnetic field lines, they are able to penetrate toroidal gaps between individual monoblocks of the target plate structure and can deliver rather intense heat loads to monoblock side faces near the gap entrance. To verify that this ELM-induced loading, predicted by both ion orbit simulations and particle in cell simulations, really does occur, two dedicated experiments have been performed on the ASDEX Upgrade tokamak. In both experiments a model toroidal gap structure of similar dimensions to those of the ITER divertor target monoblocks was exposed to a series of identical H-mode discharges with strong type-I ELMs. The effects arising from the gyro motion of hot ELM ions were identified by inverting, in the second experiment, the directions of both toroidal field and plasma current, thus reversing the ion gyration direction. The local distribution of incident ion flux on the gap side faces was quantified by pre- and post-exposure analysis of platinum marker layers to determine quantitatively the erosion rate of the platinum marker. The results fully confirm the ion orbit code predictions with respect to the penetration depth of incident ions with gyro orbits of similar or larger radius than the gap width. Moreover, the results confirm that ELM ions do indeed arrive at the divertor with their typical pedestal energies and also allow conclusions to be drawn regarding the corresponding intra-ELM ion particle and power flux, which is not easy to quantify using Langmuir probes.

Pure Be, Be-O and Be-O-C thin coatings were deposited using high-power impulse magnetron sputtering (HiPIMS) with and without incorporation of deuterium. The coatings produced without deuterium were implanted afterwards with 15 keV 2H+ ion beams with a fluence limited to 2 × 1017 ion/cm2 in order to mitigate the damage imposed by ion irradiation and prevent a fast gas release. The as-deposited and as-implanted coatings were analysed by IBA techniques, namely by elastic and Rutherford backscattering spectrometries (EBS and RBS, respectively), nuclear reaction analysis (NRA) and by time-of-flight elastic recoil detection analysis (ToF-ERDA). Despite distinct deuterium depth profiles in the implanted samples, the results show that for the present ion implantation and deposition parameters, similar retained amounts are revealed in the films loaded by ion implantation or during the HiPIMS deposition, assuring ion implantation as a competitive and reliable method for fuel incorporation in thin Be-based films for retention studies in controlled conditions. Keywords: Beryllium coatings, Deuterium, HiPIMS, Ion implantation

Iron-tungsten (Fe-W) mixed films were exposed to the low flux deuterium plasma of GyM in order to study the behavior of the sputtering yield with the ion fluence and temperature of the samples. From literature, it is known that an increase of the former lowers the Fe-W layers’ sputtering yield as a consequence of the preferential sputtering of Fe leading to an enrichment in W of the outermost layers. An opposite trend was instead found for the latter probably due to the inter-diffusion of Fe and W (effective from 200 °C) resulting in the suppression of the W enrichment. Moreover, from 500 °C, also W segregation to the surface occurs. What is missing from literature is a systematic investigation of the role of temperature on W enrichment. In this work, dedicated experiments in GyM were carried out to fill this gap. After exposure, W enrichment was evaluated by Rutherford Backscattering Spectrometry (RBS) and inferred from measuring the eroded thickness of the samples using RBS and profilometer. Concerning the Fe-W sputtering yield as a function of fluence, it decreases by a factor of ∼3 between the lowest (3.0×1022D+m−2) and the highest fluence (9.0×1023D+m−2) values considered. The other main result is that, at the lowest fluence, the exposure at room temperature leads to an erosion of the Fe-W samples more pronounced than that associated to the exposure at 500 °C.

Net erosion of plasma-facing materials was investigated at the low-field-side (outer) strike-point area of the ASDEX Upgrade (AUG) divertor during H-mode discharges with small and frequent ELMs. To this end, Au and Mo marker samples with different surface morphologies and geometries were exposed to plasmas using the DIM-II divertor manipulator. The results were compared to existing erosion and deposition patterns from various L- and H-mode experiments, in the latter case the main difference was the size and frequency of the ELMs.We noticed that increasing surface roughness reduces net erosion but less than what is the case in L-mode. On the other hand, net-erosion rates in H-mode are generally 2–5 times higher than the corresponding L-mode values, in addition to which exposure in H-mode conditions results in strong local variations in the poloidal and toroidal erosion/deposition profiles. The latter observation we associate with the large migration length, on the order of several cm, of the eroded material, resulting in strong competition between erosion and re-deposition processes especially at poloidal distances > 50 mm from the strike point. Considerable net erosion was measured throughout the analysed poloidal region unlike in L-mode where the main erosion peak occurs in the vicinity of the strike point. We attribute this qualitative difference to the slow decay lengths of the plasma flux and electron temperature in the applied H-mode scenario.Both erosion and deposition require detailed analyses at the microscopic scale and the deposition patterns may be drastically different for heavy and light impurities. Generally, the rougher the surface the more material will accumulate on locally shadowed regions behind protruding surface features. However, rough surfaces also exhibit more non-uniformities in the quality or even integrity of marker coatings produced on them, thus complicating the analyses of the experimental data.We conclude that local plasma parameters have a huge impact on the PFC erosion rates and, besides incident plasma flux, surface morphology and its temporal evolution have to be taken into account for quantitative estimates of erosion rates and PFC lifetime under reactor-relevant conditions.

In this work we report on the structure, morphology, composition, chemical bonding and optical properties of tantalum oxynitride (Ta–O–N) thin films prepared by reactive direct current magnetron sputtering. The films have been investigated by grazing incidence x-ray diffraction, x-ray reflectivity, grazing incidence small angle x-ray scattering, time-of-flight elastic recoil detection analysis, x-ray photoelectron spectroscopy and spectroscopic ellipsometry. The composition and the partial pressure of the reactive atmosphere (N2  +  O2) have been varied in order to find conditions suitable for the -TaON phase production. As prepared thin films are amorphous and annealing at °C is necessary to promote crystallization. We discuss the role of N2 gas on the kinetics of sputtered particles and its influence on the oxidation rate and porosity of the growing film. The anion composition in Ta–O–N films strongly depends on the reactive gas condition during the deposition. We found that the O/N ratio in -TaON films increases with more N2 or O2 gas in the chamber, whereas the corresponding absorption onset and valence band maximum show a blue shift of up to 0.5 eV. These results were related to the non-stoichiometry in -TaOxNy  crystallites with x  >  y . [ABSTRACT FROM AUTHOR]

In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature. [ABSTRACT FROM AUTHOR]

Thin films of tantalum nitride (Ta–N) have been prepared by reactive magnetron deposition under various nitrogen partial pressures and subsequently annealed (Ta  =  450–950 °C). The structure, density, composition and electrical resistivity of the prepared films were systematically investigated. A phase map was constructed from the results of structural analysis. With increasing of from 0 to 0.2, a single-phase or two-phase mixture films of tetragonal Ta, Ta2N ( °C), ϵ-TaN ( °C), θ-TaN ( °C) and fcc δ-TaN are sequentially observed. For –0.45, the as grown and annealed films exhibit δ-TaN structure. Amorphous films grown in the –0.75 range crystallize as cubic Ta2N3 upon annealing at °C or as δ-TaN at °C. A cubic Ta2N3 is grown at highest (0.85), which decomposes to δ-TaN at °C. The N     / Ta atomic ratio in the film linearly increases for –0.5, ranging from 0 to 2.1, while the mass density monotonically decreases with . Upon annealing, a part of N atoms out-diffuses from the films deposited at . The electrical resistivity strongly depends on both and Ta. However, in the as grown and annealed δ-TaN films the resistivity was of the order of 100–1000 cm. In these films, a correlation between the resistivity and the average number of defects (Ta vacancies and N atom excess) is observed. Finally, the influence of thermally introduced oxygen on the films resistivity has been revealed. [ABSTRACT FROM AUTHOR]

We report on the formation of Ge/Si quantum dots with core/shell structure that are arranged in a three-dimensional body centered tetragonal quantum dot lattice in an amorphous alumina matrix. The material is prepared by magnetron sputtering deposition of Al2O3/Ge/Si multilayer. The inversion of Ge and Si in the deposition sequence results in the formation of thin Si/Ge layers instead of the dots. Both materials show an atomically sharp interface between the Ge and Si parts of the dots and layers. They have an amorphous internal structure that can be crystallized by an annealing treatment. The light absorption properties of these complex materials are significantly different compared to films that form quantum dot lattices of the pure Ge, Si or a solid solution of GeSi. They show a strong narrow absorption peak that characterizes a type II confinement in accordance with theoretical predictions. The prepared materials are promising for application in quantum dot solar cells. [ABSTRACT FROM AUTHOR]

Plasma-wall interaction in magnetic fusion devices is responsible for wall changes and plasma pollution with major safety issues. It is investigated both in situ and ex situ , especially by realizing large scale dedicated post-mortem campaigns. Selected parts of the walls are extracted and characterized by several techniques. It is important to extract hydrogen isotopes, oxygen or other element content. This is classically done by ion beam analysis and thermal desorption spectroscopy. Raman microscopy is an alternative and complementary technique. The aim of this work is to demonstrate that Raman microscopy is a very sensitive tool. Moreover, if coupled to other techniques and tested on well-controlled reference samples, Raman microscopy can be used efficiently for characterization of wall samples. Present work reviews long experience gained on carbon-based materials demonstrating how Raman microscopy can be related to structural disorder and hydrogen retention, as it is a direct probe of chemical bonds and atomic structure. In particular, we highlight the fact that Raman microscopy can be used to estimate the hydrogen content and bonds to other elements as well as how it evolves under heating. We also present state-of-the-art Raman analyses of beryllium- and tungsten-based materials, and finally, we draw some perspectives regarding boron-based deposits.

Time-of-flight Rutherford backscattering spectroscopy (ToF-RBS) with incident heavy ions offers a substantially improved depth resolution compared to conventional RBS with incident He ions. The new Garching ToF-RBS detector is located at a scattering angle of 150° with a free flight path of 1.313 m and a time resolution of 600 ps. The experimentally achieved depth resolution at the surface of W-containing Fe samples is 2–3 nm using incident Si ions. Model systems consisting of Fe layers with 0.7, 1.5 and 4.2 at% W and EUROFER steel (containing 0.34 at% W + Ta) were eroded by 200 eV D ions to a fluence of 1023 D/m2 at 310 K and 900 K. W depth profiles were measured using ToF-RBS, light impurities at the surface were detected using time-of-flight elastic recoil detection analysis (ToF-ERDA). The data sets from the two techniques were analyzed self-consistently. In all cases W enrichment at the surface was observed. The enrichment at 310 K is in good agreement with SDTrimSP simulations if the experimentally achieved depth resolution is taken into account. Annealing of the model systems with 0.7 and 1.5 at% W to 900 K for 10 h in vacuum resulted also in a W-enriched surface layer. Keywords: Rutherford Backscattering Spectroscopy, RBS, ToF-RBS, Tungsten surface enrichment, EUROFER, MultiSIMNRA

Quantitative analysis of materials from Heavy Ion PIXE spectra remains impeded by the lack of reliable X-ray production cross section (XPCS) data. Although efforts at experimental Heavy Ion induced XPCS measurements still continue, Multiple Ionisation (MI) effects, which are not fully described by theory, render simulations of heavy ion PIXE data unreliable for large Z 1 /Z 2 collisions, especially at low energies. This is also exacerbated by the random selection of projectile-target combinations for measured and reported experimental data available to validate theory. This study explored heavy ion induced X-ray production cross section deviations from those induced by protons at the same ion velocity. This enabled evaluations of the degree to which cross sections are enhanced through MI effects, with the aim of predicting XPCS due to heavy ion impact. The evaluation was carried out through the scaling of experimental heavy ion to theoretical proton cross section ratios (R), which were then used for the interpolation of XPCS in the same target element for 'missing' projectiles within the range of evaluation. Here we present measurements of heavy ion induced total L-shell XPCS in Bi, carried out to determine HI/p MI induced deviations due to C, F, Cl and Ti projectiles at an ion velocity range of (0.2-1.0) MeV/nucleon., (© 2023. The Author(s).)

MeV SIMS is a type of secondary ion mass spectrometry (SIMS) technique where molecules are desorbed from the sample surface with ions of MeV energies. In this work, we present a novel system for molecular imaging of organic materials using a continuous analytical beam and a start trigger for timing based on the detection of secondary electrons. The sample is imaged by a collimated primary ion beam and scanning of the target with a lateral resolution of ∼20 μm. The mass of the analyzed molecules is determined with a reflectron-type time-of-flight (TOF) analyzer, where the START signal for the TOF measurement is generated by the secondary electrons emitted from a thin carbon foil (∼5 nm) placed over the beam collimator. With this new configuration of the MeV SIMS setup, a primary ion beam with the highest possible electronic stopping can be used (i.e., highest secondary molecular yield), and samples of any thickness can be analyzed. Since the electrons are collected from the thin foil rather than from the sample surface, the detection efficiency of secondary electrons is always the same for any type of analyzed material. Due to the ability to scan the samples by a piezo stage, samples of a few cm in surface size can be imaged. The imaging capabilities of MeV SIMS are demonstrated on crossing ink lines deposited on paper, a thin section of a mouse brain, and a fingerprint deposited on a thick Si wafer to show the potential application of the presented technique for analytical purposes in biology and forensic science.

Glass fragments found in crime scenes may constitute important forensic evidence when properly analyzed, for example, to determine their origin. This analysis could be greatly helped by having a large and diverse database of glass fragments and by using it for constructing reliable machine learning (ML)-based glass classification models. Ideally, the samples that make up this database should be analyzed by a single accurate and standardized analytical technique. However, due to differences in equipment across laboratories, this is not feasible. With this in mind, in this work, we investigated if and how measurement performed at different laboratories on the same set of glass fragments could be combined in the context of ML. First, we demonstrated that elemental analysis methods such as particle-induced X-ray emission (PIXE), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS), particle-induced Gamma-ray emission (PIGE), instrumental neutron activation analysis (INAA), and prompt Gamma-ray neutron activation analysis (PGAA) could each produce lab-specific ML-based classification models. Next, we determined rules for the successful combinations of data from different laboratories and techniques and demonstrated that when followed, they give rise to improved models, and conversely, poor combinations will lead to poor-performing models. Thus, the combination of PIXE and LA-ICP-MS improves the performances by ∼10-15%, while combining PGAA with other techniques provides poorer performances in comparison with the lab-specific models. Finally, we demonstrated that the poor performances of the SEM-EDS technique, still in use by law enforcement agencies, could be greatly improved by replacing SEM-EDS measurements for Fe and Ca by PIXE measurements for these elements. These findings suggest a process whereby forensic laboratories using different elemental analysis techniques could upload their data into a unified database and get reliable classification based on lab-agnostic models. This in turn brings us closer to a more exhaustive extraction of information from glass fragment evidence and furthermore may form the basis for international-wide collaboration between law enforcement agencies.

Thin films containing 3D-ordered semiconductor quantum wires offer a great tool to improve the properties of photosensitive devices. In the present work, we investigate the photo-generated current in thin films consisting of an interconnected 3D-ordered network of Ge quantum wires in an alumina matrix. The films are prepared using nitrogen-assisted magnetron sputtering co-deposition of Ge and Al 2 O 3 . We demonstrate a strong photocurrent generation in the films, much stronger than in similar films containing Ge quantum dots. The enhanced photocurrent generation is the consequence of the multiple exciton generation and the films' specific structure that allows for efficient carrier transport. Thin film with the largest nitrogen content showed enhanced performance compared to other thin films with 1.6 excitons created after absorption of a single photon at an energy nearly equal to the double bandgap value. The bandgap value depends on the geometrical properties of the quantum wires, and it is close to the maximum of the solar irradiance in this case. In addition, we show that the multiple exciton generation is the most pronounced at the photon energy values equal to multiple values of the thin film bandgap., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.

This work explores the possibility of depth profiling of inorganic materials with Megaelectron Volt Secondary Ion Mass Spectrometry using low energy primary ions (LE MeV SIMS), specifically 555 keV Cu 2+ , while etching the surface with 1 keV Ar + ions. This is demonstrated on a dual-layer sample consisting of 50 nm Cr layer deposited on 150 nm In 2 O 5 Sn (ITO) glass. These materials proved to have sufficient secondary ion yield in previous studies using copper ions with energies of several hundred keV. LE MeV SIMS and keV SIMS depth profiles of Cr-ITO dual-layer are compared and corroborated by atomic force microscopy (AFM) and time-of-flight elastic recoil detection analysis (TOF-ERDA). The results show the potential of LE MeV SIMS depth profiling of inorganic multilayer systems in accelerator facilities equipped with MeV SIMS setup and a fairly simple sputtering source., (© 2022. The Author(s).)

Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) with MeV primary ions offers a fine balance between secondary ion yield for molecules in the mass range from 100 to 1000 Da and beam spot size, both of which are critical for imaging applications of organic samples. Using conically shaped glass capillaries with an exit diameter of a few micrometers, a high energy heavy primary beam can be collimated to less than 10 μm. In this work, imaging capabilities of such a setup are presented for some organic samples (leucine-evaporated mesh, fly wing section, ink deposited on paper). Lateral resolution measurement and molecular distributions of selected mass peaks are shown. The negative influence of the beam halo, an unavoidable characteristic of primary beam collimation with a conical capillary, is also discussed. A new start trigger for TOF measurements based on the detection of secondary electrons released by the primary ion is presented. This method is applicable for a continuous primary ion beam, and for thick targets that are not transparent to the primary ion beam. The solution preserves the good mass resolution of the thin target setup, where the detection of primary ions with a PIN diode is used for a start trigger, reduces the background, and enables a wide range of samples to be analyzed.

The low energy range (a few 100 keV to a few megaelectronvolts) primary ion mode in MeV secondary ion mass spectrometry (MeV SIMS) and its potential in exploiting the capabilities of conventional (keV) SIMS and MeV SIMS simultaneously were investigated. The aim is to see if in this energy range of both types of materials, inorganic and organic, can be simultaneously analyzed. A feasibility study was conducted, first by analyzing the dependence of secondary ion yields in indium tin oxide (ITO, In 2 O 5 Sn) and leucine (C 6 H 13 NO 2 ) on various primary ion energies and charge states of a Cu beam, within the scope of equal influence of electronic and nuclear stopping. Expected behavior was observed for both targets (mainly nuclear sputtering for ITO and electronic sputtering for leucine). MeV SIMS images of samples containing separate regions of Cr and leucine were obtained using both keV and MeV primary ions. On the basis of the image contrast and measured data, the benefit of a low energy beam is demonstrated by Cr + intensity leveling with leucine [M + H] + intensity, as opposed to a significant contrast at a higher energy. It is estimated that, by lowering the energy, the leucine [M + H] + yield efficiency lowers roughly 20 times as a price for gaining about 10 times larger efficiency of Cr + yield, while the leucine [M + H] + yield still remains sufficiently pronounced.

Recently demonstrated 3D networks of Ge quantum wires in an alumina matrix, produced by a simple magnetron sputtering deposition enables the realization of nanodevices with tailored conductivity and opto-electrical properties. Their growth and ordering mechanisms as well as possibilities in the design of their structure have not been explored yet. Here, we investigate a broad range of deposition conditions leading to the formation of such quantum wire networks. The resulting structures show an extraordinary tenability of the networks' geometrical properties. These properties are easily controllable by deposition temperature and Ge concentration. The network's geometry is shown to retain the same basic structure, adjusting its parameters according to Ge concentration in the material. In addition, the networks' growth and ordering mechanisms are explained. Furthermore, optical measurements demonstrate that the presented networks show strong confinement effects controllable by their geometrical parameters. Interestingly, energy shift is the largest for the longest quantum wires, and quantum wire length is the main parameter for control of confinement. Presented results demonstrate a method to produce unique materials with designable properties by a simple self-assembled growth method and reveal a self-assembling growth mechanism of novel 3D ordered Ge nanostructures with highly designable optical properties.

Time-of-flight secondary ion mass spectrometry (TOF SIMS) is a well-established mass spectrometry technique used for the chemical analysis of both organic and inorganic materials. In the last ten years, many advances have been made to improve the yield of secondary molecular ions, especially those desorbed from the surfaces of organic samples. For this reason, cluster ion beams with kiloelectron volt energies for the excitation were mostly used. Alternatively, single-ion beams with megaelectron volt energies can be applied, as was done in the present work. It is well-known that a secondary molecule/ion yield depends strongly on the primary ion stopping power, but the nature of this dependence is not completely clear. Therefore, in the present work, the secondary ion yield from the phthalocyanine blue (C 32 H 16 CuN 8 , organic pigment) was measured for the various combinations of ion masses, energies, and charge states. Measured values were compared with the existing models for ion sputtering. An increase in the secondary yield with the primary ion energy, electronic stopping, velocity, and charge state was found for different types of primary ions. Although this general behavior is valid for all primary ions, there is no single parameter that can describe the measured results for all primary ions at once.

Aims: Hepatic insulin resistance, induced by fat, occurs before peripheral resistance and leads to prediabetes and diabetes. If insulin resistance is detected earlier, lifestyle changes could prevent or delay disease development. Therefore, we analysed lipids in the liver and serum of prediabetic and diabetic mice by MeV TOF-SIMS with a focus on diacylglycerols (DAGs) as the best predictor of (liver) resistance., Methods: Glucose impairment was spontaneously developed or induced by HFD in NOD/LtJ mice, and prediabetic and diabetic mice were selected according to their glucose levels. MeV TOF-SIMS was applied to image the lipid distribution in the liver and to relatively quantify lipids related to insulin resistance in both the liver and serum., Results: The same lipids were detected in the liver and serum but with different intensities between mice. The intensity of DAGs and fatty acids was higher in the diabetic than that in the prediabetic liver. Imaging of liver tissue showed a more compact density of prediabetic (non-fatty) than diabetic liver with DAG remodelling in diabetes. DAGs, which are greatly increased in diabetic serum, were successfully detected and quantified already in prediabetes., Conclusion: MeV TOF-SIMS applied to the serum presents an excellent tool for in vivo monitoring of disease development over time., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Determination of the deposition order of different writing tools is very important for the forensic investigation of questioned documents. Here we present a novel application of two ion beam analysis (IBA) techniques: secondary ion mass spectrometry using MeV ions (MeV-SIMS) and particle induced X-ray emission (PIXE) to determine the deposition order of intersecting lines made of ballpoint pen ink, inkjet printer ink, and laser printer toners. MeV-SIMS is an emerging mass spectrometry technique where incident heavy MeV ions are used to desorb secondary molecular ions from the uppermost layers of an organic sample. In contrast, PIXE provides information about sample elemental composition through characteristic X-ray spectra coming from greater depth. In the case of PIXE, the information depth depends on incident ion energy, sample matrix and self-absorption of X-rays on the way out from the sample to the X-ray detector. The measurements were carried out using a heavy ion microprobe at the Ruđer Bošković Institute. Principal component analysis (PCA) was employed for image processing of the data. We will demonstrate that MeV-SIMS alone was successful to determine the deposition order of all intersections not involving inkjet printer ink. The fact that PIXE yields information from deeper layers was crucial to resolve cases where inkjet printer ink was included due to its adherence and penetration properties. This is the first time the different information depths of PIXE and MeV-SIMS have been exploited for a practical application. The use of both techniques, MeV-SIMS and PIXE, allowed the correct determination of deposition order for four out of six pairs of samples.

The recent development of new advanced materials demands extensive effort in developing new analytical techniques that can provide insight into material composition at the nanoscale, particularly at surfaces and interfaces, which is important for both fabrication and material performance. Here, we present a proof of principle for a new setup used for thin-film characterisation and depth profiling based on a combination of time-of-flight elastic recoil detection analysis (TOF-ERDA) and Ar sputtering. A quantitative depth profiling with a best achievable surface depth resolution of ~2 nm can be realised for the entire layer, which is important for the precise determination of thickness and composition of samples that are several tenths of a nanometre thick. The performance of TOF-ERDA with Ar sputtering was demonstrated using 15 nm Cu evaporated onto a Si substrate. The advantages and limits of the method are discussed in detail.

Nanostructuring of surfaces and two-dimensional materials using swift heavy ions offers some unique possibilities owing to the deposition of a large amount of energy localized within a nanoscale volume surrounding the ion trajectory. To fully exploit this feature, the morphology of nanostructures formed after ion impact has to be known in detail. In the present work the response of a rutile TiO 2 (001) surface to grazing-incidence swift heavy ion irradiation is investigated. Surface ion tracks with the well known intermittent inner structure were successfully produced using 23 MeV I ions. Samples irradiated with different ion fluences were investigated using atomic force microscopy and grazing-incidence small-angle X-ray scattering. With these two complementary approaches, a detailed description of the swift heavy ion impact sites, i.e. the ion tracks on the surface, can be obtained even for the case of multiple ion track overlap. In addition to the structural investigation of surface ion tracks, the change in stoichiometry of the rutile TiO 2 (001) surface during swift heavy ion irradiation was monitored using in situ time-of-flight elastic recoil detection analysis, and a preferential loss of oxygen was found.

In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si3N4 membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

We report on the formation of Ge/Si quantum dots with core/shell structure that are arranged in a three-dimensional body centered tetragonal quantum dot lattice in an amorphous alumina matrix. The material is prepared by magnetron sputtering deposition of Al2O3/Ge/Si multilayer. The inversion of Ge and Si in the deposition sequence results in the formation of thin Si/Ge layers instead of the dots. Both materials show an atomically sharp interface between the Ge and Si parts of the dots and layers. They have an amorphous internal structure that can be crystallized by an annealing treatment. The light absorption properties of these complex materials are significantly different compared to films that form quantum dot lattices of the pure Ge, Si or a solid solution of GeSi. They show a strong narrow absorption peak that characterizes a type II confinement in accordance with theoretical predictions. The prepared materials are promising for application in quantum dot solar cells.

The ordering of quantum dots in three-dimensional quantum dot lattices is investigated by grazing-incidence small-angle X-ray scattering (GISAXS). Theoretical models describing GISAXS intensity distributions for three general classes of lattices of quantum dots are proposed. The classes differ in the type of disorder of the positions of the quantum dots. The models enable full structure determination, including lattice type, lattice parameters, the type and degree of disorder in the quantum dot positions and the distributions of the quantum dot sizes. Applications of the developed models are demonstrated using experimentally measured data from several types of quantum dot lattices formed by a self-assembly process.