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We present the development of time-of-flight/energy (TOF-E) telescope for elastic recoil detection analysis (ERDA) in UTTAC at the University of Tsukuba. The designs of the TOF tube are introduced. The performance for the quantification and mass resolution for light elements is confirmed on a CaTaO x N y film deposited on a Si substrate. The results are cross-checked by the data taken by an existing ΔE-E telescope ERDA system, which was previously installed in MALT at The University of Tokyo. The newly developed system can be used to reveal the relationship between the film deposition condition and the contamination quantitatively on a Si-Al-N (SiAlN) film on a SiO 2 substrate. Finally, the analysis of a triple-layered metal nitrides film on a soda glass substrate, in which each layer has a thickness of 10 to15 nm, is shown. From the analysis of the surface peak of oxygen, the time resolution corresponds to depth resolution of 2.1 nm at the surface. The overall practical depth resolution conservatively estimated as better than 10 nm, because the depth profiles of various elements show clear counters corresponding to the three layers. [ABSTRACT FROM AUTHOR]

• The stability of H signals in a-C:H films in ERDA using a 3.4 MeV He beam. • The H stability was observed in DLC, GLC, and low-H PLC. • The H stability was correlated with Raman scattering and photoluminescence. • The a-C:H films with the H stability can be good candidates for ERDA standards. The hydrogen (H) loss of hydrogenated amorphous carbon (a-C:H) films, such as polymer-like, diamond-like, and graphite-like carbon films, was evaluated during elastic recoil detection analysis (ERDA) conducted using 3.4 MeV He2+. Films were formed on Si substrates via a plasma-based ion implantation and deposition method. The Raman scattering spectrometry of the films was then conducted, and except for the case of the polymer-like carbon film that had a strong photoluminescence background, two characteristic peaks corresponding to the disorder and graphite bands were observed in all cases. ERDA measurements indicated that there was no H loss in films with weak or negligible photoluminescence, whereas a decrease in H signals was clearly observed for the film with strong photoluminescence. The polymer polyphenylenesulfide (PPS: C 6 H 4 S), which is used as a standard material for ERDA measurements, showed a significant decrease in H signals under the same conditions. In comparison with the PPS, we concluded that a-C:H films with negligible photoluminescence can be used as standard materials for ERDA measurements. [ABSTRACT FROM AUTHOR]

Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nano-indentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds. [ABSTRACT FROM AUTHOR]

Zn1-xMgxO epitaxial films with Mg concentrations 0≤x≤0.3 were grown by plasma-assisted molecular beam epitaxy on a-plane sapphire substrates. Precise determination of the Mg concentration x was performed by elastic recoil detection analysis. The bandgap energy was extracted from absorption measurements with high accuracy taking electron-hole interaction and exciton-phonon complexes into account. From these results a linear relationship between bandgap energy and Mg concentration is established for x≤0.3. Due to alloy disorder, the increase of the photoluminescence emission energy with Mg concentration is less pronounced. An analysis of the lattice parameters reveals that the epitaxial films grow biaxially strained on a-plane sapphire. [ABSTRACT FROM AUTHOR]

We demonstrated a position-sensitive-like detector (PSD) based on a scanning solidstate detector (scanning-SSD) in HERDA for improvement of detection limit for hydrogen. The new detection system enables us to separate the signals of interest from background noises, which can be attributed to the signals produced by particles of non-interest, by measuring the particle energies from a detected position and SSD outputs. As results, we succeeded to improve the detection limit for hydrogen and deuterium down to 2.0 × 1019 at./cm3 (~0.02 at.%) and 1.6 × 1020 at./cm3 (~0.16 at.%) with the data acquisition time of ~220 s and 120 s at each position of the SSD, respectively. The main contributions to the improvement of the detection limits are the high detection efficiency of the new detection system and the removal of stray particles, which mainly consist of low energy H0 and H+. We simulated the leading edge shape of the obtained HERDA spectra of hydrogen by SIMNRA and Monte Carlo simulation (CORTEO). The comparative studies between the experiments and simulations revealed the non-negligible contribution of H+ recoils generated by multiple scattering. [ABSTRACT FROM AUTHOR]

• The influence of tungsten fuzz on recoiled helium energy spectra was investigated. • The shapes of spectra from fuzz deviate from a smooth sample. • The total amount of helium can be derived robustly using a surrogate smooth sample. • Accurate determination of depth profiles requires the correct microstructure. The influence of fuzz-like tungsten surface structures on the shape of helium energy spectra recoiled by an incident 10 MeV 16O beam was investigated by computer simulations using the program STRUCTNRA and a phenomenological two-dimensional tungsten fuzz model. The model describes fuzz by a random distribution of inclined rectangular filaments containing tungsten and 1 at% helium. The mean width of the filaments was varied from 10 to 100 nm and the mean filament height was varied from 10 to 1500 nm while keeping the total amount of material constant. The shapes of the helium recoil energy spectra are modified by the fuzz, the deviations from the spectrum of a smooth sample increase with increasing filament widths and heights. The total numbers of detected helium recoils remain surprisingly independent of the filament widths and heights. A surrogate smooth sample with depth profile yielding a recoil energy spectrum identical to a fuzzy sample can be always found. The total amount of He can be derived robustly using the surrogate sample. [ABSTRACT FROM AUTHOR]

An elastic recoil detection analysis (ERDA) system in air for hydrogen analysis was developed in the Wakasa Wan Energy Research Center. This system uses a thin silicon–nitride window to separate the air and vacuum regions, and the beam is irradiated through the window. Elements scattered by the beam enter the vacuum region through the same window, and are detected by an ERDA detector located there. The hydrogen sensitivity of the system was investigated by analyzing high molecular films. We used a helium beam and a stopper foil in front of the ERDA detector to ensure that only hydrogen was detected. Hydrogen energy spectra for the high molecular films and background were obtained. [ABSTRACT FROM AUTHOR]

Quantitative hydrogen analysis is a useful tool in various fields, such as the energy, catalysts, and semiconductor fields, because the quality of materials or devices strongly depends on their hydrogen concentrations. To analyze the concentration of hydrogen quantitatively, the elastic recoil detection analysis (ERDA) method is widely used. In this report, the number fraction of hydrogen in silicon nitride was analyzed using a simple time-of-flight ERDA method over a depth range of 25 nm from the surface without the use of a stopping foil, an additional analyzer, or charged particle optics. The number fractions of the other elements (silicon and nitrogen) in the sample were also analyzed through backscattering measurements. [ABSTRACT FROM AUTHOR]

Abstract Transmission Electron Microscopy (TEM), Rutherford Backscattering Spectrometry in random and aligned to Si 001-channel direction, and Elastic Recoil Detection Analysis (ERDA) techniques were employed to characterize SiC structures obtained by Ion Beam Synthesis. C+ ions at 40 keV were implanted up to a fluence of 2.8 × 1017 cm−2 into a (001) Si substrate capped by a SiO 2 layer. Samples with SiO 2 -cap thicknesses of 110, 190 and 240 nm were compared. For the first two of them, 72% and 11% of C+ ions, respectively, are directly implanted into the Si substrate, however, for the later, no carbon directly reaches the substrate. C+ implantation was performed with samples held at 600 °C and, afterwards, they were annealed at 1250 °C for 2 h under a flux consisting of a mixture of 99% Ar and 1% O 2. ERDA demonstrates that C redistribution occurs in the 240 nm SiO 2 -cap and TEM, Selected Area Diffraction and Channeling revealed an almost continuous cubic and epitaxial SiC layer of about 5–7 nm on the Si surface. This SiC nanolayer presented the optimum crystalline quality, from the standpoint of HRTEM imaging and Channeling results. This synthesis was exclusively based on C migration to the SiO 2 /Si interface, followed by SiC nucleation during interfacial reconstruction of the crystal structure. The improved quality is justified because the interface is not affected by any implantation damage. On the other end, the synthesis by using the 110 nm SiO 2 -cap is obtained by direct C inclusion into the Si structure, but also results in epitaxial SiC. The 190 nm SiO 2 -cap showed, however, a strong regression in the quality: it revealed misaligned grains of SiC immerse in an amorphous narrow layer. Two distinct mechanisms are responsible for SiC synthesis, depending on the cap-layer thickness, and the influence of the radiation damage for each is discussed. [ABSTRACT FROM AUTHOR]

Abstract The paper reports studies of pure, polycrystalline iron samples exposed to proton implantation with energies of 73 keV and 173 keV and doses of 3 × 1015, 1016 and 3 × 1016 cm−2. Additionally, two samples were exposed to multiple implantation with different energies and fluencies. Variable energy positron beam (VEP) was applied to the detection of irradiation-induced defects and their distribution. In turn, elastic recoil detection (ERD) method was used to estimate hydrogen concentration and its range. Analysis of VEP results was performed with VEPFIT code. The strong reduction of positron diffusion lengths in the implanted layers point out the presence of defects with high concentration. The thicknesses of these layers are in good agreement with hydrogen range evaluated by ERD. However, the presence of defects with lower concentration behind implanted zone was also detected when the free fitting was performed. The long range effect cannot be excluded. [ABSTRACT FROM AUTHOR]

The authors investigate sputtering of a Ti3SiC2 compound target at temperatures ranging from RT (no applied external heating) to 970 °C as well as the influence of the sputtering power at 850 °C for the deposition of Ti3SiC2 films on Al2O3(0001) substrates. Elemental composition obtained from time-of-flight energy elastic recoil detection analysis shows an excess of carbon in all films, which is explained by differences in the angular distribution between C, Si, and Ti, where C scatters the least during sputtering. The oxygen content is 2.6 at. % in the film deposited at RT and decreases with increasing deposition temperature, showing that higher temperatures favor high purity films. Chemical bonding analysis by x-ray photoelectron spectroscopy shows C–Ti and Si–C bonding in the Ti3SiC2 films and Si–Si bonding in the Ti3SiC2 compound target. X-ray diffraction reveals that the phases Ti3SiC2, Ti4SiC3, and Ti7Si2C5 can be deposited from a Ti3SiC2 compound target at substrate temperatures above 850 °C and with the growth of TiC and the Nowotny phase Ti5Si3Cx at lower temperatures. High-resolution scanning transmission electron microscopy shows epitaxial growth of Ti3SiC2, Ti4SiC3, and Ti7Si2C5 on TiC at 970 °C. Four-point probe resistivity measurements give values in the range ∼120 to ∼450 μΩ cm and with the lowest values obtained for films containing Ti3SiC2, Ti4SiC3, and Ti7Si2C5. [ABSTRACT FROM AUTHOR]

The analysis of thin films using heavy ions offers some specific advantages over traditional light ion beam analysis techniques. In this work, polyethylene terephthalate (PET) substrate was implanted with 150 keV Ag+-ions at low temperature at fluences of 1.00 x 1016 and 5.00 x 1016 ions/cm2. A newly constructed low temperature chamber equipped with heavy ion Rutherford Backscattering Spectrometry (HI-RBS) and Elastic Recoil Detection Analysis (HI-ERDA) detectors was used for sample characterisation, using 14 MeV 28Si4+-ions at an irradiation fluence of about 2.40 x 1013 ions/cm2. The analyses were carried out at room temperature and with the sample holder cooled to liquid nitrogen temperature. Silicon beam irradiation effects on the PET were then compared at room- and low-temperature measurements. Significant hydrogen loss of about 64 % relative to pristine PET was observed for room-temperature measurements, whereas for low-temperature analyses the hydrogen loss was about 12 %. The significant release of hydrogen atoms from the surface region of the PET was accompanied by a drastic change in the surface layer composition. For room-temperature measurements, there was surface enhancement of the carbon content by about 31 %, while for low-temperature measurements the accumulation was about 9 % compared to the nominal 45 % content in pristine PET. [ABSTRACT FROM AUTHOR]

Abstract Extensive characterization is needed to understand how the physicochemical properties of polymeric membranes are related to their transport properties and to allow optimization of membrane design. Currently, most techniques characterize the (near)-surface region of the membrane, even though its bulk obviously also plays a significant role in the final membrane performance. To achieve depth-profiles of the elemental composition of both integrally skinned asymmetric (ISA) and thin-film composite (TFC) membranes, elastic recoil detection (ERD), an ion beam analysis technique, is now introduced to the field as a potentially highly valuable tool to complement for instance XPS, EDX or RBS. The determination of the complete elemental composition, importantly also including hydrogen, as function of the membrane thickness allows to gain knowledge about its depth-heterogeneity at an impressive combination of ca. 15 nm resolution with ppm-range sensitivity. This very low detection limit additionally allows the analytical quantification of e.g. remnants from synthesis conditions. The potential as well as the pitfalls of ERD as a novel, valuable technique for membrane characterization are critically discussed and illustrated by the determination of the thickness of polyamide-based top-layers of TFC membranes. Graphical abstract fx1 Highlights • ERD is successfully applied in membrane science. • The elemental composition of integrally skinned membranes and thin-film composite membranes is determined. • Elemental depth-profiling with a resolution of 15 nm and a sensitivity in the ppm-range is achieved. • ERD is also used to detect remnants from synthesis conditions and to determine the top-layer thickness of TFC membranes. [ABSTRACT FROM AUTHOR]

Abstract Graphene oxide (GO) is prepared as a self-supporting thin film by a liquid solution of GO. The so-obtained GO films have been characterized in terms of thickness and density. The GO film composition and trace elements have been measured with Rutherford backscattering spectrometry (RBS) and Elastic recoil detection analysis (ERDA), using MeV helium ion beams. The presence of crystalline and amorphous phases has been also investigated with X-ray diffraction (XRD) and the morphology by scanning electron microscopy (SEM). Information about the GO film structure, oxidation degree and thickness has been deduced by means of Fourier transform infrared spectroscopy (FT-IR), Raman and optical spectroscopy (ultraviolet-visible-near infrared spectroscopy, UV-Vis-nIR). In particular, the GO film thickness varies from sub-micrometric values up to micrometric ones. Furthermore, the GO film heating in air up to 60 °C produces oxidation effects as deduced from the interpretation of our data. Highlights • Graphene oxide and reduced graphene oxide have special properties and can be used in different fields with micro- and sub-micrometric thickness. • Graphene oxide is prepared by chemical and physical method as a self-supporting film with different thickness. • The preparation in air at room temperature produces graphene oxide with less oxygen and hydrogen content compared to that prepared at 60°C. • The ion or laser irradiation of graphene oxide produce reduced graphene oxide. • Detailed physical analyses permit to evince the chemical changes of graphene due to the temperature of the film preparation. [ABSTRACT FROM AUTHOR]

We investigated the effects of epitaxial strain on the anion composition, crystal structure, and electrical transport properties of topotactically hydrogen substituted SrTiOxHy epitaxial thin films grown on (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7(001) (LSAT), LaSrAlO4(001) (LSAO), and DyScO3(110) (DSO) substrates. Hydrogen substitution for oxygen (y ≈ 3 − x) was confirmed by X-ray diffraction measurements, elastic recoil detection analysis, and energy dispersive X-ray spectroscopy. Tensile-strained SrTiOxHy/DSO films exhibited a higher hydrogen content (y = 0.87) than compressive-strained SrTiOxHy/LSAT films (y = 0.20) and almost relaxed SrTiOxHy/LSAO films (y = 0.56) after a reaction with CaH2 at 500 °C for 72 h, probably owing to enhanced oxygen diffusion under tensile strain. Metallic conduction was observed in the SrTiOxHy thin films with a low hydrogen content (y = 0.10 and 0.16 on LSAT, y = 0.20 on LSAO, and y = 0.40 on DSO), while further hydrogen substitution (y = 0.56 on LSAO and y = 0.57 and 0.87 on DSO) induced insulating behavior at low temperatures. Furthermore, comparing SrTiOxHy/LSAO (y = 0.56) and SrTiOxHy/DSO (y = 0.57) films revealed that the carrier activation ratio is drastically reduced by tensile strain. These results demonstrate the potential to strain-engineer chemical and physical properties of transition metal oxyhydride thin films. [ABSTRACT FROM AUTHOR]

Oxygen with a kinetic energy of 20 keV is implanted in a silicon wafer (100) at different fluences, followed by post-implantation thermal annealing (PIA) performed at temperatures ranging from 1000 to 1200 °C, in order to form luminescent silicon nanoparticles (SiNPs) and also to reduce the damage induced by the implantation. As a result of this procedure, a surface SiO x layer (with 0 < x < 2) with embedded crystalline Si nanoparticles has been created. The samples yield similar luminescence in terms of peak wavelength, lifetime, and absorption as recorded from SiNPs obtained by the more conventional method of implanting silicon into silicon dioxide. The oxygen implantation profile is characterized by elastic recoil detection (ERD) technique to obtain the excess concentration of Si in a presumed SiO 2 environment. The physical structure of the implanted Si wafer is examined by grazing incidence X-ray diffraction (GIXRD). Photoluminescence (PL) techniques, including PL spectroscopy, time-resolved PL (TRPL), and photoluminescence excitation (PLE) spectroscopy are carried out in order to identify the PL origin. The results show that luminescent SiNPs are formed in a Si sample implanted by oxygen with a fluence of 2 × 10 17 atoms cm −2 and PIA at 1000 °C. These SiNPs have a broad size range of 6–24 nm, as evaluated from the GIXRD result. Samples implanted at a lower fluence and/or annealed at higher temperature show only weak defect-related PL. With further optimization of the SiNP luminescence, the method may offer a simple route for integration of luminescent Si in mainstream semiconductor fabrication. [ABSTRACT FROM AUTHOR]

Diamond-like carbon (DLC) films were tribochemically formed from ambient hydrocarbons on the surface of a highly stable nanocrystalline Pt-Au alloy. A sliding contact between an alumina sphere and Pt-Au coated steel exhibited friction coefficients as low as μ = 0.01 after dry sliding in environments containing trace (ppb) organics. Ex situ analysis indicated that the change in friction coefficient was due to the formation of amorphous carbon films, and Raman spectroscopy and elastic recoil analysis showed that these films consist of sp 2 /sp 3 amorphous carbon with as much as 20% hydrogen. Transmission electron microscopy indicated these films had thicknesses exceeding 100 nm, and were enhanced by the incorporation of worn Pt-Au nanoparticles. The result was highly wear-resistant, low-friction DLC/Pt-Au nanocomposites. Atomistic simulations of hydrocarbons under shear between rigid Pt slabs using a reactive force field showed stress-induced changes in bonding through chain scission, a likely route towards the formation of these coatings. This novel demonstration of in situ tribochemical formation of self-lubricating films has significant impact potential in a wide range of engineering applications. [ABSTRACT FROM AUTHOR]

A double MCP (micro channel plate) system is developed for the improvement of detection limit in HERDA (high-resolution elastic recoil detection analysis) for hydrogen (H) and its isotope. One MCP detects the recoils of hydrogen (or deuterium (D)), the other one detects the secondary electrons emitted from stopper foil. While the dark current noise is reduced down to 2%, the detection efficiency still remains as 80%. The improved detection limit for H and D achieved ∼6.3 × 10 19 atoms/cm 3 (∼0.06 at.%) for 360 s and ∼2.3 × 10 20  atoms/cm 3 for 114 s, respectively. It is also found that the contributions of recoils of other light elements to the detection limit are crucial from the comparison with the previous study, in which both H and D are included in the samples. The developed system successfully determines the D depth profile in a SiO 2 thin film ( t  = 5 nm) caused by the D 2 annealing. [ABSTRACT FROM AUTHOR]

Muzzle brakes (MBs) have a great effect on reducing the recoil force of weapons during firing. In this paper, optimum MB efficiency, MB force and recoil force for (12.7 mm x 99 mm) sniper rifle have been studied. The objective is to obtain the optimum area of side openings, inclination angle and number of chambers for the MB in order to increase the MB efficiency and MB force and thereby to decrease their coil force of the weapon. An analytical model for calculating MB efficiency, MB force and weapon recoil force for MBs of two, three and four chambers has been established. This Model is then utilised in combination with design of experiment and response surface method statistical techniques to develop a smooth response function which can be efficiently used in optimisation formulation. Finally, multi objectives generic algorithm optimisation method has been employed to find the optimum MB design parameters. The optimisation results show that the three or four chambers MBs have no significant effect on reducing the weapon recoil force compared with the two chamber MB for this sniper rifle. [ABSTRACT FROM AUTHOR]

Hydrogen is one of the alternatives as clean fuel for our growing demands for energy. However, its storage for practical applications is a challenge due to low energy density. The interaction mechanism between the hydrogen gas and the host involved plays a vital role to explore its potential application as hydrogen storage material. So, in the present work, we have studied the interaction of Graphene oxide with hydrogen gas at different pressures varying from 70 mbar to 900 mbar at room temperature using reliable in-situ X-ray diffraction technique. XRD patterns showed that the hydrogen gas induced strain up to ∼6.3% in GO films for 1% and 10% hydrogen atmosphere. The interaction mechanism was studied qualitatively using Raman spectroscopy and Fourier transform infra-red (FTIR) spectroscopy. Elastic recoil detection analysis (ERDA) technique was employed to determine the concentration of hydrogen in GO film which increased from ∼1.7 × 10 22 atoms/cc (for pristine GO) to ∼ 9.5 × 10 22 atoms/cc after exposing to 100% hydrogen environment at 900 mbar pressure. [ABSTRACT FROM AUTHOR]

In this paper, we have discussed the non-relativistic and relativistic treatment of the recoil energy of photon due to the nuclear transition and atomic transition and calculated the total energy of the recoil event for atomic and nuclear transition which concluded that the relativistic recoil energy of photon due to nuclear transition is 105 times greater than that of atomic transition. [ABSTRACT FROM AUTHOR]

Angioplasty and stenting are standard treatment options for both stabile occlusive coronary artery disease and acute myocardial infarctions. Over the last years, several biodegradable stent systems have entered pre-clinical and clinical evaluation and into clinical practice. A strong supporting scaffold is necessary after angioplasty to prevent elastic recoil of the vessel but in the long term a permanent metallic stent will only impair normal physiology of the artery wall. Thus, the main advantage of a resorbable system is the potential for better vessel recovery and function in the long term. The new stent systems differ from traditional stents in size and biological responses and questions have risen regarding their mechanical strength and increased risk of stent thrombosis. Here, we present current treatment options with biodegradable scaffolds, discuss further key areas for improvements and review novel technological advances in the context of all up-to-date clinical trial information. New material choices are also covered as well as special considerations for pre-clinical testing. [ABSTRACT FROM AUTHOR]

Li depth profiles in Au/Si/LiPON/LCO/Au (LCO = LiCoO 2 , LiPON = Li 3.3 PO 3.8 N 0.2 ) thin films battery under charging condition, prepared on self-supporting Al substrate, have been in situ measured by means of transmission elastic recoil detection (TERD) and Rutherford backscattering spectroscopy (RBS) techniques not only with 5.4 MeV He 2+ ion beam without absorber, but also 9 MeV O 4+ ion beam with Al absorber. In experiments with 5.4 MeV He 2+ , well-resolved step-wise TERD spectra have been observed, from which thickness and Li composition of constituent films of the battery are directly estimated. The Li transport from LCO to Si films through LiPON as well as return-back of Li from Si to LCO films and Li leakage into the Al substrate out of the battery system by over-charging under charging condition have been observed in the experiments both 5.4 MeV He 2+ and 9 MeV O 4+ . The latter result indicates that these techniques are applicable to testing degradation of the battery performance by repetition of charging and discharging. Both results are compared in details with each other. [ABSTRACT FROM AUTHOR]

Hydrogen loss from a -SiN x :H films under irradiation with 100 MeV Ag 7+ ions using elastic recoil detection analysis (ERDA) experiment is reported. The results are explained under the basic assumptions of the molecular recombination model. The ERDA hydrogen concentration profiles are composed of two distinct hydrogen desorption processes, limited by rapid molecular diffusion in the initial stages of irradiation, and as the fluence progresses a slow process limited by diffusion of atomic hydrogen takes over. Which of the aforesaid processes dominates, is determined by the continuously evolving Hydrogen concentration within the films. The first process dominates when the H content is high, and as the H concentration falls below a certain threshold (H critical ) the irradiation generated H radicals have to diffuse through larger distances before recombining to form H 2 , thereby significantly bringing down the hydrogen evolution rate. The ERDA measurements were also carried out for films treated with low temperature (300 °C) hydrogen plasma annealing (HPA). The HPA treated films show a clear increase in H critical value, thus indicating an improved diffusion of atomic hydrogen, resulting from healing of weak bonds and passivation of dangling bonds. Further, upon HPA films show a significantly higher H concentration relative to the as-deposited films, at advanced fluences. These results indicate the potential of HPA towards improved H retention in a -SiN x :H films. The study distinguishes clearly the presence of two diffusion processes in a -SiN x :H whose diffusion rates differ by an order of magnitude, with atomic hydrogen not being able to diffuse further beyond ∼ 1 nm from the point of its creation. [ABSTRACT FROM AUTHOR]

Utilization of combined particle-induced X-ray emission (PIXE) and elastic backscattering (EBS) spectrometry for the direct elemental analysis of thick solid biological samples was thoroughly discussed. Powdered samples pressed as pellets were directly analyzed. Combination of applying low ion beam currents, random scanning of the sample across the beam during data acquisition, and using special sample holder enabled effective minimization of local ion beam heating. This subsequently inhibited potential element loss during ion beam irradiation. Matrix elements were determined from multiple EBS spectra, which were acquired using three different ion beam energies. Subsequently, averaging of the elemental concentrations obtained was achieved using novel MultiSIMNRA software. Moreover, combined EBS spectrometry, nuclear reaction analysis (NRA), and elastic recoil detection analysis (ERDA) measurements were used to overcome the limitations of using EBS separately and subsequently obtain accurate matrix element concentrations. The validity of the PIXE/EBS system for the direct elemental analysis of thick biological samples was comprehensively evaluated. The obtained concentration values demonstrated reliable results for most investigated elements (5–15%), starting from sodium onwards. The non-satisfying results were evaluated and justified. [ABSTRACT FROM AUTHOR]

The European X-ray Free Electron Laser has recently started with operation for users. An approximately 3 m long ultra high vacuum laser heater section is implemented to overcome possible electron bunch instabilities. We describe the process of determining the oxide layer thickness and surface roughness on test samples of the internal surface material in the laser heater vacuum chambers using elastic recoil detection analysis and optical surface profiling. The results are compared to specified values and show that surface roughness on the samples is larger than the requested maximum, with RMS deviations from a mean plane of up to 1.76 μm for 0.60 × 0.45 square millimeter scans. The maximum oxide layer thickness is 5.5 nm on non-electropolished surfaces assuming cuprous oxide with density 6.0 g per cubic centimeter and 4.0 nm on electropolished surfaces. [ABSTRACT FROM AUTHOR]

In this paper, power suppression detection in mu band known as event-related desynchronization during a simultaneous EEG–fMRI recording is addressed. Simultaneous EEG-fMRI experiments provide great opportunities to recognize relation between the active areas in the brain, discovered by fMRI, and EEG events. However, decoding EEG is challenging as a result of artifacts which MRI scanner applies on EEG. Ballistocardiogram (BCG) is one of the main destructive artifacts which deteriorates EEG rhythms specially in mu band. The proposed method, is a supervised time-frequency decomposition algorithm which estimates underlying rhythms of EEG signals recorded in MRI scanner. In the proposed method, a multi layer decomposition approach using three criteria is developed to extract brain oscillations. This goal is achieved by eliminating the artifact related components at each decomposition layer as a result of removing useless extracted components in each layer. Performance of the proposed method is evaluated using synthetic and real EEG. The achieved results from synthetic data confirm the ability of the proposed method to extract mu rhythms when different levels of noise exist. In addition, proposed algorithm is applied on a set of real EEG acquired in a simultaneous EEG–fMRI recording. Estimated ERD confirms the superiority of the developed algorithm in terms of estimating changes of mu rhythms. Moreover, an EEG–fMRI integration is performed to explore the correlation between blood oxygenation level dependent (BOLD) in fMRI and ERD of mu rhythm in EEG. [ABSTRACT FROM AUTHOR]

The hyperfine interactions effect on the results from RDDS experiments is considered. Expressions for the influenced observables are derived within the context of application of the Differential decay curve method for data analysis. In particular, a formula for the lifetime is given where, on the one hand, measured quantities—peak areas of the shifted (fast) components and on the other hand, modeled perturbed angular distribution functions are taken into account. This formula allows for both study of the hyperfine interactions and correct derivation of the lifetime of the investigated level. [ABSTRACT FROM AUTHOR]

We present results for the detection of low energy nuclear recoils in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An 241 Am- 9 Be fast neutron source is used in order to obtain neutron–nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the keV energy region was measured by observing the 5.9 keV line of a 55 Fe X-ray source, with energy resolution of 10 % ( σ ). The toolkit GEANT4 was used to simulate the irradiation of the detector by an 241 Am- 9 Be source, while SRIM was used to calculate the Ionization Quenching Factor (IQF), the simulation results are compared with the measurements. The potential of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searches (via coherent elastic scattering). [ABSTRACT FROM AUTHOR]

In this paper, the differential cross-section of D( 12 C,D) 12 C elastic recoil reaction at a recoil angle of 30° in the energy region of 3.4–9.0 MeV was measured. The sample Pd/TiDx/Si was prepared by magnetron sputtering, and a relative determination method was employed to avoid the uncertainties in solid angle and the number of the incident ions. The uncertainty of measured data is approximately 4.4%. [ABSTRACT FROM AUTHOR]

Interactions of vertically aligned multiwall carbon nanotubes (CNTs) with high energy He+ beams were studied using elastic recoil detection analysis and ion beam channeling. The relationship between the elastic recoil of hydrogen, the depth of He-H interactions, and the number of carbon atoms per volume (denoted as effective density) was calculated. Ion channeling was observed in CNT forests shorter than 40 µm. It was found that the effective density and hydrogen content were inversely correlated with the CNT height. In compliance with channeling and density calculations, the authors propose that this effect is due to the weakening of Van-der-Waals forces in taller CNT forests. The methodology suggested in this work may be extended to assessing densities of thin, highly porous materials. [ABSTRACT FROM AUTHOR]

In fast ignition research, a divergence of laser-generated hot electrons is a serious problem. Using diamond like carbon (DLC) cones is one of the realistic solutions to this problem. However, it is difficult to make a stand-alone DLC cone because it needs a thick DLC layer. In this paper, we report survey findings of preparation conditions for a thick DLC layer. DLC layers were prepared by using plasma–based ion implantation and deposition system. Acetylene gas or toluene vapor was used as a source. After trials of many deposition conditions, it is found that low gas pressure and low RF power condition is suitable for a thick DLC deposition. Properties of the made DLC layers were measured by near edge X-ray absorption fine structures (NEXAFS) and elastic recoil detection analysis (ERDA). It is found that these DLC layers have typical hydrogenated amorphous DLC properties. Based on these results, we succeeded in making stand-alone DLC cones. [ABSTRACT FROM AUTHOR]

Amorphous tungsten oxide thin films were deposited by sputtering at different O 2 /Ar ratios onto conducting substrates. Ion intercalation and diffusion in the films was studied by electrochemical impedance spectroscopy measurements in the frequency range 10 mHz–100 kHz and for potentials between 1.0 and 3.2 V vs. Li/Li + , using the film as working electrode in a Li + containing electrolyte. The impedance data were in very good agreement with anomalous diffusion models. Different models were found to be applicable at potentials >1.8 V and <1.8 V. At high potentials ion intercalation was found to be reversible and an anomalous diffusion model describing ion hopping was favored. At low potentials ion intercalation was found to be irreversible and ion trapping takes place. In this latter range an anomalous diffusion model for the case of non-conserved number of charge carriers gave the best fit to experimental data. We obtained potential dependent diffusion coefficients in the range from 10 −9 to 10 −11 cm 2 /s, and anomalous diffusion exponents in the range 0.1 to 0.4, with the films deposited at lower O 2 /Ar ratios exhibiting the higher values. [ABSTRACT FROM AUTHOR]

Elastic recoil detection analysis (ERDA) is a well established technique and it offers unique capabilities in thin film analysis. Simultaneous detection and depth profiling of all elements, including hydrogen, is possible only with time-of-flight ERDA. Bragg ionization chambers or Δ E - E detectors can also be used to identify the recoiling element if sufficiently high energies are used. The chief limitations of time-of-flight ERDA are the beam induced sample damage and the requirement of a relatively large accelerator. In this paper we propose a detector setup, which could be used with 3 MeV to 6 MeV medium heavy beams from either a single ended accelerator ( 40 Ar) or from a tandem accelerator ( 39 K). The detector setup consists of two timing detectors and a gas ionization chamber energy detector. Compared to use of very heavy low energy ions the hydrogen recoils with this beam have sufficient energy to be detected with current gas ionization chamber energy detector. To reduce the beam induced damage the proposed detector setup covers a solid angle larger than 1 msr, roughly an order of magnitude improvement over most time-of-flight ERDA setups. The setup could be used together with a small accelerator to be used for light element analysis of approximately 50 nm films. The concept is tested with 39 K beam from a 1.7 MV Pelletron tandem accelerator with the Jyväskylä ToF-ERDA setup. In addition to the measurements effects related to low energies and increase in the solid angle are simulated with Monte Carlo methods. [ABSTRACT FROM AUTHOR]