Use Of Ion Beam Techniques Research Articles

Cultural heritage science at CNA (seville, Spain): Applications of XRF and IBA techniques to art and archaeological objects.

The use of nuclear analytical techniques has experienced an extraordinary growth in recent decades in the field of cultural heritage. Nowadays, their use in the study of objects of interest in heritage has become essential. An important effort has been made since the 90s by the archaeometry research group of the Centro Nacional de Aceleradores, CNA (Sevilla, Spain) to develop different non-destructive analytical techniques for the study of art and archeological objects. These efforts were initially focused on the use of Ion Beam techniques (IBA) and lately in the development of portable X-Ray Fluorescence (XRF) equipment, including microbeam versions with the implementation of polycapillary lenses (μXRF and confocal XRF).The different methods and instrumentation developed in the past years at CNA are presented in this work and several applications illustrate the capabilities for the analysis of different types of objects: jewelry, coins, paintings, ceramics, etc. Advantages and limitations of the different techniques are shown together with examples of how the combination of several of those methods can overcome some of the limitations are presented.

IBC - ION BEAM CENTER

In the Ion Beam Center (IBC), various set-ups – electrostatic accelerators, ion implanters, plasma-based ion implantation equipment, low-energy ion tools, an ion microscope etc. – are combined into a unique facility for research and applications using ion beams. Almost all ions from stable chemical nuclides are available in the ion energy range from 10 eV to about 60 MeV. In addition to broad beams, also focused (down to 1 nm) and highly-charged (charge state up to 45+) ion beams, or ions extracted from a plasma can be provided. In total, the IBC operates more than 30 dedicated tools or beamline end-stations. The specific expertise of IBC is the modification and analysis of solids by energetic ions aimed to develop novel materials for information technology, electronics or energy systems. In addition, ion beam analysis techniques became of increasing importance for interdisciplinary fields like geochemistry, climate or environmental research and resources technology. Special add-on services offered ensure a successful realization of user experiments. Based on a long-term expertise, specific equipment and common commercial procedures, the IBC is strongly active in the use of ion beam techniques for industrial applications aimed to initiate valuable product innovation.

Proton Induced X-ray Emission Study on the Content of Whale Tooth

The use of Ion beam technique for assaying small amounts of trace elements and major elements distribution has grown rapidly in recent years. Major and minor elemental composition of teeth has been extensively studied. In this work, elements content in teeth of whale were analyzed by the Proton Induced X-ray Emission (PIXE). This work is an attempt to investigate the history of mammal's different annual rings layer of whale tooth. High levels of Trace elements such as Zn and Sr were detected in the teeth. By analysis of elemental composition and evaluation of trace elements in different layer, the route of the whale movement and the status of pollution of environment were obtained. The result indicated that the technique is suitable to obtain minor and trace constituents of the teeth. The obtained results are discussed in detail and these results are compared withavailable data. The methods which are widely used in the analysis of trace elements were reported elsewhere (12). In this work, PIXE (13) was used to investigate the history of history of mammals by analyzing different annual rings layer of whale tooth. . Information about the trace elements in tooth is important for several reasons. (i) Most mammals have life spans that exceed 1 year. (ii) Information can be used for evaluation the environmental pollution in the Sea or Ocean (ii) Information also can be used to know the migration, seasons and the diets of mammals.

The effect of helium ion implantation on the relaxation of strained InGaAs thin films

Previous work on pseudomorphic SiGe on Si has shown that a significant reduction in the threading dislocation density can be achieved through appropriate ion beam processing. Helium ion implantation was used in an analogous study to induce strain relaxation within strained pseudomorphic InGaAs layers on GaAs through the intentional introduction of subsurface damage without the introduction of surface nucleated dislocations and their associated threading segments. Wafers of fully-strained 28 nm thick films of In 0.24Ga 0.76As were separately implanted with helium doses of 5 × 10 14, 2 × 10 15, and 1 × 10 16 cm −2 at 25 keV. These wafers became substrates for additional InGaAs film growth. The final InGaAs films always exhibited lower residual strain as compared to films grown directly on a control substrate of non-implanted GaAs. The broadening of the X-ray peaks indicates an increase in dislocation density within the InGaAs films and the strain relaxation was found to occur with a significant increase in surface roughness. This result stands in contrast to related work on SiGe films on Si where a reduction of the threading dislocation density within a SiGe film was observed. The reaction of the InGaAs/GaAs structure and materials to ion irradiation, with local disturbance to the stoichiometry, could preclude the use of ion beam techniques for realizing a reduction in threading dislocation density during strain relaxation.

Micromechanical measurements of ion-beam treated steel

The paper presents recent methods of surface modification based on the use of ion-beam techniques: ion implantation and ion-beam mixing (IBM). The methodology of sample preparation, the advantages and drawbacks of the technology as well as the results of micromechanical tests (friction and wear measurements) performed on the ion-beam treated samples are presented. The results obtained on both, untreated and ion-beam mixed high-speed steel samples clearly show that in the first stage of the wear process the worn zone expands well above the sample surface. This growth is less pronounced in ion-beam mixed samples. Nuclear microprobe measurements revealed the redistribution of alloying elements in wear tracks. The friction coefficient and wear extent in ion-beam treated samples are reduced when compared with the untreated ones.

Amalgam components drift in teeth-toxicity risks: A preliminary approach

The use of ion beam techniques applied to teeth studies have been extensive in what concerns the major elements distribution. However, it is not clarified whether amalgam components are absorbed and drifted through teeth material, although the toxicity of the elements used in amalgams, such as Hg, are well known. This work is an attempt to assess a possible teeth contamination originated by the amalgams. Therefore, teeth with metallic amalgam, as well as healthy ones, were studied. The teeth were longitudinally cut and each slice was scanned from the inner region to the surface enamel for elemental profiles determination purposes using Particle Induced X-ray Emission (PIXE) and Synchrotron Radiation X-ray Fluorescence (SRXRF) techniques. High levels of Zn, Ag, Sn, Hg and Pb were found along the scanned teeth restored with the metallic amalgam. The elemental distribution patterns suggest diffusion of these elements in the teeth material from amalgam constituents.

On the complementary use of ion beam techniques in the near surface analysis of implanted alloys

A combination of RBS, PIXE and resonant elastic backscattering was applied to determine the depth profiles and doses of Y implants in Cr and NiCr alloys, the mass contents of Cr and Ni respectively, and the oxygen composition in surface layers of these alloys before and after implantation. Only through the simultaneous use of PIXE analysis was a severe error in the alloy preparation revealed. A Fe content of about 5% was found in one of the nominal binary alloys, influencing the corrosion behaviour of this material significantly. This level of Fe content was undiscernible from the Ni and Cr continuum in the RBS spectra. For the analysis of the oxygen surface layers with the 3.03 MeV resonance of 4He ions, two evaluation programs were used and compared: GISA and RUMP in a modified form, enabling the use of non-Rutherford cross sections.

Concept and status of the new sample preparation and analyzing facility at Bochum

The technical conditions of the activities at the Dynamitron Tandem Accelerator Laboratory at Bochum in the field of ion beam modification and analysis of thin films will be improved. A new 500 kV accelerator with high energy resolution of the ion beams as well as a UHV system consisting of several chambers are presently being built up. The beam lines of the new accelerator and of the 4 MV Tandem are interconnected, providing a wide range of ion species and energies at the target sites. The UHV system not only allows the use of ion beam techniques but also provides standard electron spectroscopic techniques for surface analyses. For sample preparation techniques such as standard furnace evaporation, electron gun evaporation and rapid thermal processing are available.

Enhancement of coating adhesion to carbide substrates by use of ion beam techniques : K. Sato, H. Hasuyama (Nippon Tungsten Co, Fukouka, Japan), Nippon Tungsten Rev., vol 26, 1994, 29–35

Enhancement of coating adhesion to carbide substrates by use of ion beam techniques : K. Sato, H. Hasuyama (Nippon Tungsten Co, Fukouka, Japan), Nippon Tungsten Rev., vol 26, 1994, 29–35

Ion Mixing of Pulsed Laser Deposited Hydroxylapatite (HA)

AbstractThe use of ion-beam techniques to enhance selected properties of bioactive materials, such as the adhesion of hydroxylapatite (HA) coatings on titanium-based substrates has been investigated. In this study, very thin HA films on titanium substrates were created by pulsed laser deposition techniques. Ion irradiations were carried out using 260-keV argon ions, with fluences of 0.25-50×1015ions/cm2, and at room temperature. Rutherford backscattering spectrometry was used to evaluate sample composition before and after irradiation. The amount of mixing was quantified by the mixing rate (the amount of atomic displacement due to an irradiation fiuence). This pilot data indicates that mixing was evident after sufficient ion irradiation. The ramification of this preliminary study has provided a quantitative measure of ion mixing as a potential prosthetic biomaterial surface modification technique.

The use of ion beam techniques to characterize lead diffusion in minerals

The characterization of diffusion of lead and other trace elements in certain mineral phases has great significance in reconstructing the thermal history of the earth's crust. Such studies permit better interpretation of ages'' obtained from isotopic dating. This study uses ion implantation to introduce lead into the minerals apatite and zircon. Diffusion profiles are obtained using Rutherford backscattering (RBS) and the results fit with a model to determine D. Results for apatite over the temperature range 600--900{degree}C show agreement with earlier results obtained traditional geologic techniques. This suggests that radiation damage induced by ion implantation has little effect on diffusion in this case. This approach is both simple and useful in studying diffusion over a temperature range of geologic interest without inordinate annealing times. 17 refs., 5 figs.

The current status of metallization in integrated circuit applications

With the progression towards increased packing density in integrated circuits more and more emphasis has to be given to solving metallization problems. Interconnection resistance, high current density and design complexity are forcing process engineers to use metals other than the traditional aluminium alloys and to use multiple levels of interconnection. Metallization processes can now represent more than 50% of the fabrication process. Enhanced deposition techniques are being utilised in an effort to reduce contact resistance and to give reliable metallization over high aspect ratio features where planarization of both interlayer dielectric and metal layer is becoming essential in the most complex metallization schemes. In this paper, the current status of integrated circuit interconnection and metallization will be reviewed. The requirements of metallization in devices will be described from both the electrical and fabrication points of view. Particular emphasis will be given to the use of ion beam techniques, e.g. ion beam cleaning, ion mixing, bias sputtering and back sputtering for conformal deposition and planarization.

Spectroscopy of the hydrogen molecular ion at its dissociation limit

Previous theoretical and experimental work on the ion and its deuterium isotopes HD+ and D£ is briefly reviewed. Spectroscopic studies of the vibration rotation levels are discussed, and recent work on the infrared photodissociation of the high-lying vibrational levels is described. Earlier work that made use of ion-beam techniques to study the vibration—rotation levels of HD+ is reviewed, and compared with the most recent theoretical predictions. The nuclear-hyperfine and spin—rotation structure of HD+ is described, and recent observations of the vibration-rotation satellite lines that will yield absolute values of the deuterium hyperfine constants are presented. We conclude by describing our attempts to observe radiofrequency—infrared double-resonance spectra.

Multiple hydrogen occupancy of vacancies in Fe

The binding of multiple deuterium (D) atoms to vacancies in iron (Fe) is investigated both experimentally, by use of ion-beam techniques, and theoretically, by use of the effective-medium scheme. The experimental D-release stages are accounted for by trapping at vacancies with a binding enthalpy that depends on occupancy. It is found that for 1–2 D in a vacancy, the trap strength is 0.63 eV, whereas the binding enthalpy for 3–6 D in a vacancy is 0.43 eV. These results are in good agreement with predictions from the effective-medium theory.

Use of ion beam techniques for studying the leaching properties of lead implanted silicates

Na and H depth profiling has been performed on samples of soda-lime glass and albite subjected to Pb ion implantation and leaching, by means of resonant nuclear reactions. Before leaching, the implanted albite samples show a particular Na depth profile with a marked depletion at the range of the incident Pb ions but an unchanged surface concentration. For soda-lime glass, a Na surface depletion has been noted, which increases with the ion dose. After leaching, the compositional change in albite is limited to the implanted layer, whereas in soda-lime glass it proceeds at much larger depths and exhibits a linear time dependence for short leach times. In addition Pb implantation is found to drastically increase H penetration in vitreous silica. Such ion induced effects are discussed with reference to the use of ion implantation to simulate internal irradiation due to α-decay.

The use of ion beam techniques in the analysis of catalysts

This paper describes the application of Rutherford backscattering in the analysis of copper chromite and bismuth molybdate catalysts. The performance of copper chromite catalysts in the production of fatty alcohols was found to be influenced by the presence of BaO in the catalysts as analyzed by RBS, PIXE and the O 16(d, p)O 17 nuclear reaction. In the case of bismuth molybdate, the thermal decomposition of the catalyst was studied by RBS and the nuclear reaction for oxygen. Samples annealed in oxygen or vacuum at temperatures of 400°C tended to decompose into a 2:1 compound which probably is more stable and responsible for the catalytic behavior.

The Use of Ion Beam Techniques in Catalysis

It has become increasingly obvious recently that ion beam methods can make a significant contribution to the preparation and characterisation of heterogeneous catalysts. Normally such catalysts are composed of one or more metals or compounds dispersed over a high surface area support material, such as alumina or silica. It is important to be able to measure the relative concentrations of the catalytic components (and any associated impurities) over the support, and, to some extent, within the support. Proton Induced X-ray Emission is particularly appropriate for this purpose. It may be used also to identify the presence of poisoning elements which have been responsible for catalyst deactivation. However, one of the most common causes of catalyst deactivation is carbon deposition on to its exposed surfaces. In this case, a particularly useful diagnostic technique is Prompt Nuclear Activation Analysis, since it can be rendered specific for carbon to the exclusion of other associated elements. So far as catalyst preparation is concerned, there are of course many conventional chemical routes: for example, these may involve impregnating the support with suitable catalytic metal salts, thereby utilising the high surface area properties of the support to create the dispersion of the catalytic elements. However, it has now been realised that two ion beam techniques, namely ion implantation and sputtering, provide an alternative method of producing novel catalysts.

Ion Beam Analysis of Surface Modifications in Tokamaks

This paper briefly reviews the use of ion beam techniques to study surface modification of samples exposed to tokamak plasma discharges. Primary emphasis is given to a continuing study of samples exposed at the first wall of the Princeton Large Torus (PLT) tokamak throughout its operating life. Both impurity flow and hydrogen recycle effects are investigated. Laboratory hydrogen implantations at 200-400 eV suggest a method to determine the mean ion temperature at the wall from the hydrogen saturation trapping dependences in Si samples.

Use of ion beam techniques to characterize thin plasma grown GaAs and GaAlAs oxide films

Thin plasma grown films of GaAs oxides and GaAlAs oxides have been analyzed using the combined techniques of Rutherford backscattering, ion-induced X-rays, and nuclear resonance profiling. The stoichiometries of the films have been quantitatively determined and can be combined with other Auger profiling results to characterize the films. The ion-induced X-ray technique has been checked against other measurements to determine its accuracy. For uniform films such as these the X-ray measurements can provide accurate quantitative results.