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The electrophysical properties and the resistive switching effect in ITO/SiNx/Si memristor structures have been investigated. A silicon nitride film ~200 nm thick with a Si/N ratio varying with depth has been deposited on a silicon substrate by chemical vapor deposition. The current–voltage characteristics of ITO/SiNx/Si-p structures have shown that the conduction mechanism in a high-resistivity state depends on the properties of the nitride film and is described in terms of the Pool–Frenkel model, which takes into consideration electron hops between neighboring traps. When the polarity of the voltage applied to the structure changes sign, conducting channels in the nitride film break down and the structure switches over to a high-resistivity state. The photoswitching effect has been discovered in the ITO/SiNx/Si structure, which opens up a new frontier for using memristors in silicon optoelectronic devices.

The spectral dependences (λ = 0.35–1.0 μm) of transmittance and reflectance R of binary TiAlN nitride thin films deposited by magnetron sputtering of the target on glass substrates and on Si wafers have been measured. TiAlN/Si films 0.5 μm thick were exposed to single nanosecond (70 ns) pulses of ruby laser radiation in order to study the effect of thermophysical processes laser-induced in TiAlN on the dynamics of R(t) at probe wavelengths λ1 = 0.53 μm and λ2 = 1.06 μm and on the state of the zones of laser irradiation, which was studied by optical and scanning electron microscopy. The dynamic change of R increase at λ1 and decrease at λ2 associated with pulsed heating of the film and which is observed in the experiment increases as irradiation energy density W increases with the approach to the threshold energy of laser ablation of nitride of ~1 J/cm2. Laser-induced thermophysical processes occurring at W = 0.6–0.9 J/cm2 lead to specific modification of the TiAlN layer with the formation of a grid of cracks due to thermal stresses arising during the action of the laser pulse. Increasing W results in a more developed cellular/mesh film structure characterized by a smaller average cell size.

In the present work, silicon nitride, and oxide films, as well as two-layered SiNx/SiO2 and three-layered SiO2/SiNx/SiO2 structures, were fabricated on p-type Si-substrates. The structure and element composition was studied by scanning electron microscopy and Rutherford backscattering spectroscopy, respectively. It was shown, spectral positions of photoluminescence maxima, as well as edge absorption, were determined by stoichiometry of SiNx layers. No electroluminescence signal was registered from single-layered silicon nitride films. The intense band at 1.9 eV dominated the electroluminescence spectra of single-layered silica film as well as two- and three-layered structures. It was attributed to silane groups in SiO2 layers. The contribution of emission from silicon nitride layers into electroluminescence of the two- and three-layered structures is discussed.

Si-rich (SiN 1.1 ) and N-rich (SiN 1.5 ) silicon nitride films were grown on the Si wafers by plasma-enhanced chemical vapor deposition. Their composition and structure were investigated by Rutherford backscattering spectroscopy and transmission electron microscopy. The effect of composition and post-deposition annealing temperature on the SiN x light-emitting properties was investigated by the examination of photoluminescence. The intensive bands for the Si-rich and N-rich nitride films were detected in the red and blue spectral ranges, respectively. Photoluminescence bands transformations for the annealed nitride films can be ascribed to the increasing K- and N-centre concentration via the Si H and N H bonds rupture and the competitive processes of defect annihilation. On the basis of photoluminescence band FWHM broadening with “ x ” increasing, the FWHM dependence on the measurement temperature and SiN x films inhomogeneous structure, the emission from the SiN 1.1 and SiN 1.5 films is attributed to the transitions between the bands of defect and tail states associated with chemical disordering.

Transition of the precision engineering and instrumentation to the widespread use of nanoscale structures and thin layers requires improved localization methods for measuring the depth of the material. Unified standards and the generally accepted methods for measuring the wear resistance and friction coefficient are not currently available. The aim of this work was the development of a universal friction machine with the simplified requirements for the preparation and the geometric shape of the sample and the opposing disc. An important requirement for the equipment and the method of measurement is the ability to measure the friction coefficient and the determination of the wear resistance of coatings and hardened layers of micron and submicron thicknesses. Another important requirement is modeling in the experiment of acyclic friction process, as close as possible to the real operating conditions of components and parts. Both of these conditions are successfully realized by using the method of «disc on plate». Implementation of «disk on plate» method was used to simplify and improve the rapid measurement, and to minimize load on the friction assembly, reduce friction pair temperature, increase the sensitivity and improve the resistive bridge thermal stabilization. The complex for the study of friction and wear processes of various materials pairs in conditions close to operational was manufactured and tested. The measuring console with a low value of the parasitic load on the measuring cell was designed. A computerized hardware and software system for the registration of the friction parameters of the process was developed. The software for processing and storage of experiment results was developed. The software is compatible with modern Windows operating systems. The file format for measurement results storage is compatible with the conventional graphic editors and could be processed by means of Exсel. The main principles of the analysis and processing of the results are consequentially described. Typical results of usage of the developed machine for friction coefficient measurements and the determination of the wear resistance of massive, homogeneous surfacehardened materials and alloys with coatings are shown. The high efficiency of the created equipment complex during investigation of coatings, optimization of coating depositing processes and the modification of the surface layers are shown in the study. The efficiency of the complex was confirmed by the study of the modified layers and micron thickness coatings. It was found that the friction coefficient and wear resistance of construction materials, modified thin microcrystalline layers and nanostructured coatings was effectively controlled by using of the created complex.

Structural and absorption properties of Te-implanted silicon layers after pulsed laser melting, equilibrium furnace annealing and rapid thermal annealing were examined and compared. The advantage of laser annealing in the formation of absorbing silicon-based layers is demonstrated. Silicon layers doped with Te up to concentrations of (3–5) × 1020 cm−3 were formed via ion implantation and pulsed laser melting. It is found that 70–90% of the embedded impurity atoms are in substitutional states in the silicon lattice. A significant increase of the absorption (to 35–65%) in the wavelength range of 1100–2500 nm is obtained, which is useful for Si-based photodiodes. The effect of energy density of the laser pulse on the structural and optical properties of Te-hyperdoped silicon is discussed. The current-voltage characteristics and the photosensitivity of Te-doped silicon photodiodes are investigated.

Spectral dependences of the small-signal surface photovoltage, Vf (л), with a region of short- wave recession have been studied experimentally and theoretically. The dependences Vf (л) are shown to enable important information concerning a modification of surface and bulk recombination properties of the photosensitive silicon material in the short-wave spectral range to be obtained experimentally with the use of a nondestructive technique. In particular, theformation of a damaged near-surface layer owing to the Fe implantation is found to bring about a significant decrease in the diffusion length (i.e. the lifetime) in the implanted layer and an increase of the effective surface recombination rate on the illuminated surface., Експериментально та теоретично дослiджено спектральнi залежностi малосигнальної конденсаторної фото-ерс Vf (л) з дiлянкою короткохвильового спаду. Показано, що в короткохвильовiй областi спектра залежностi Vf (л) дозволяють отримати з використанням експериментально неруйнiвного методу важливу iнформацiю про змiну рекомбiнацiйних властивостей поверхнi та об’єму фоточутливого кремнiєвого матерiалу. Встановлено, зокрема, що створення порушеного приповерхневого шару за рахунок iмплантацiї залiза приводить як до сильного зменшення об’ємної довжини дифузiї (тобто часу життя) в iмплантованому шарi, так i до зростання ефективної швидкостi поверхневої рекомбiнацiї на освiтлюванiй поверхнi.

The radiative properties of non-stoichiometric silicon nitride SiNx fi lms produced by plasma-enhanced chemical vapor deposition were studied. Intense room-temperature photoluminescence (PL) in the visible region was recorded after annealing for both Si-rich (x = 1.13) and N-rich (x = 1.5) silicon nitride fi lms. The position of the PL band maximum depended signifi cantly on the fi lm composition. The PL band maxima for Si-rich and N-rich SiNx fi lms were detected in the red (660 nm) and blue (450 nm) spectral regions, respectively. The effect of the annealing atmosphere on PL of the SiNx fi lms was studied. It was shown that the PL intensity depended not only on the annealing temperature but also on the annealing atmosphere. The observed features of the non-stoichiometric SiNx PL spectra were explained in terms of defect states in the SiNx band gap.

with V and III Group Ions F. Komarov, L. Vlasukova, O. Milchanin, M. Grebena,∗, I. Parkhomenko, A. Mudryi, E. Wendler and P. Zukowski Belarusian State University, Nezavisimosti ave. 4, 220030 Minsk, Belarus Scienti c and Practical Materials Research Center, National Academy of Sciences of Belarus P. Brovki Str. 17, 220072 Minsk, Belarus Institut fur Festkorperphysik, Friedrich-Schiller-Universitat Jena, Max-Wien-Platz 1, D-07743 Jena, Germany Lublin University of Technology, Nadbystrzycka 38d, 20-618 Lublin, Poland

The process of InAs and GaSb nanoprecipitates creation in Si matrix using high-fluence ion implantation of species from groups V and III followed by thermal treatment has been investigated. We have studied in detail a complex system of defects and nanocrystals in implanted layers, have compared a damage level for both systems, evaluated the influence of implantation and annealing regimes on a size of A 3 B 5 nanocrystals and on a defect distribution in implanted layers. The crystalline nature of precipitates was identified by observing Moire fringe patterns in TEM images, the Moire period showing a tendency to increase with increasing size of inclusion. A “glowing” effect was observed at the nanocrystal/Si interfaces in the dark-field TEM images of the implanted and annealed samples, this being ascribed to the presence of misfit dislocation networks at the InAs/Si and GaSb/Si interfaces generated as a result of strain relaxation in the highly mismatched A 3 B 5 /Si systems. Also we compared our results on structural characterization of “A 3 B 5 nanocrystals–Si matrix” systems with other papers.

The results of structural and optical investigation of crystalline Si with embedded InSb nanocrystals are reported. These nanocrystals were synthesized in silicon matrix by means of high-fluence “hot” implantation of Sb and In ions followed by thermal treatment. TEM gives an evidence of nanocrystal formation in implanted and annealed samples as well as an existence of microtwins and dislocation-type defects and substantial residual mechanical strains. We have identified nanocrystals as InSb from RS data. Mechanical strains in “silicon – InSb nanocrystals” system have been evaluated, too.

In this paper measurements results of electrical and optical properties of SiN x thin layers are presented. Layers were produced by chemical vapor deposition on n-type (100)-oriented silicon substrates. Measurements were performed for samples directly after deposition and for samples annealed in temperature of 1073 K. Resistance R p , capacity C p , phase angle shift θ and dielectric loss factor tgδ were the measuring parameters on AC in the frequency range from 50 Hz to 5 MHz as a function of measurement temperature from the range 20 K – 373 K. Based on this, the conductivity σ and the activation energy of conductivity were determined. Photoluminescence spectra were recorded at room temperature in the spectral region of 350 – 800 nm using a He-Cd laser source with λ=325 nm. The influence of annealing on the electrical and optical properties was explained. Current resonance phenomenon and reduction of photoluminescence spectra were observed.

We have studied the ion-beam synthesis of GaSb nanocrystals in Si by high-fluence “hot” implantation of Sb and Ga ions followed by thermal annealing. The Rutherford backscattering, transmission electron microscopy/ transmission electron di˙raction, Raman spectroscopy and photoluminescence were used to characterize the implanted layers. It was found that the nanocrystal size increases from 5 to 60 nm in the samples annealed at 900 ±C up to 20–90 nm in those annealed at 1100 ±C. For the samples annealed at 900 ±C a broad band in the region of 0.75–1.05 eV is registered in the photoluminescence spectra. The nature of this photoluminescence band is discussed.

The formation of nanodimensional InAs crystallites on Si wafers was studied by the method of high fluence implantation of As and In ions with subsequent high temperature treatment. It was found that the size and depth distributions of the crystallites depend on both the implantation temperature and the annealing conditions. A broad band in an energy range of 0.75–1.1 eV was recorded in the photolumines cence spectra of the samples.

A model of diffusion of dopant atoms implanted in silicon is presented. The model is based on the creation and migration of dopant-vacancy and dopant-self-interstitial complexes, it accounts for process nonlinearity and influence of non-uniform defects distribution as well as electric field and elastic stress on the migration of atoms. The simulation results are compared with SIMS investigations of rapid thermal annealing of phosphorus implanted in silicon. The calculated distribution agrees well with experimental data and displays anomalous diffusion phenomena specific for phosphorus (kink-and-tail).

A mobile x-ray “knife” developed by the authors is described. The device is intended for determining the profile of the spatial intensity distribution in the ionizing radiation beam. Its automated motion system combines two actuator types. Significant displacements are performed using a goniometric module with a piezoelectric actuator. The angular step of this module is 1 arc second, which corresponds to a linear displacement of 0.97 μm. As a “fine” drive, a rotating module with a piezoelectric column is used. Its linear step can be varied from 0.01 to 1 μm at a total number of steps of 1000. The x-ray knife was experimentally tested at the Kurchatov Center of Synchrotron Radiation for diagnostics of the parameters of a short-focus x-ray lens at a photon energy of 18 keV. In the vertical direction, the width of the profile for the intensity distribution in the beam formed by the lens was 2.4 μm.

The microcapillary lens, formed by air bubbles in a hollow core glass capillary filled with epoxy, is a novel design of a compound refractive lens for X-rays. The epoxy enclosed between two air bubbles has the form of a biconcave lens and acts as a positive lens for X-rays. Each individual lens is spherical with radius of curvature equal to the inner radius of the capillary. Up to 500 individual biconcave lenses can be formed in a single capillary with diameters from 50 to 500 μm. Due to the small radius of curvatures that can be achieved, microcapillary lenses typically have shorter focal lengths than those made by compression or injection molding. For example, microcapillary lenses with a focal length about 5 cm for 8 keV X-rays and 50-micron aperture are readily available. We have produced a set of lenses in a 200-micron inner-diameter glass capillary with 100–350 individual microlenses and measured their parameters at the Stanford Synchrotron Radiation Laboratory and at the Advanced Photon Source. Our investigations have also shown that the lenses are suitable for imaging applications with an X-ray tube as a source of X-rays. A simple X-ray microscope is discussed. The microscope consists of a copper anode X-ray tube, X-ray lens and CCD-camera. The object, lens and CCD-camera were placed in-line at distances to satisfy the lens formula. It is shown that the field of view of the microscope is about 1 mm and resolution is equal to 3–5 μm.

Physical as well as mathematical and technological aspects of the optimization for the forming process of dielectric microwaveguides on the basis of polymer/SiO2/Si systems with the implementation of ion irradiation technology are presented. The procedure of choice of bombarded ion parameters is presented. This information allows one to simplify the development of technological aspects of stepped and gradient microwaveguides formed on the basis of a considered system.

We have fabricated and tested short focal-length compound refractive lenses (CRLs) composed of microbubbles embedded in epoxy encased in glass capillaries. The interface between the bubbles formed 90 to 350 spherical biconcave microlenses reducing the overall focal length inversely by the number of lenses or bubbles. When compared with CRLs manufactured using other methods, the microbubble lenses have shorter focal lengths with higher transmissions and larger gains for moderate energy x rays (e.g., 7–20 keV). We used beamline 2–3 at the Stanford Synchrotron Radiation Laboratory and beamline 5BM-D-DND at the Advanced Photon Source to measure focal lengths between 100–250 mm with lens apertures varying between 97 and 321 μm. Transmission profiles were measured giving, for example, a peak transmission of 46% for a 240 mm focal length CRL at 20 keV. The focal-spot sizes were also measured yielding, for example, a vertical spot size of 1.2 μm resulting from an approximate 20-fold demagnification of the APS 23 ...

An attempt to apply the temperature peak model to describe the formation of defects and tracks in semiconductor crystals is made for the first time. The temperature dependences of model parameters, such as specific heat, thermal conductivity, and electron-phonon coupling coefficient are obtained. Agreement between the theoretical results and experimental data for InP and Ge crystals irradiated by ultrafast heavy ions indicates the adequacy of the model, with which one can evaluate the temperature of the local area near the ion trajectory, as well as the diameters of the molten region and experimentally observed track region. The diameter of the cylindrical molten region that forms along the path of 250-MeV Xe+ ions in InP is predicted to be 20 nm, and the measured cross-sectional diameters of the tracks fall into the range 7–15 nm.

An original approach and a single-ion-beam experimental setup for in situ ion implantation combined with the deposition of various materials on metals are suggested. The simulation system developed makes it possible to characterize ion-assisted deposition, as well as to analyze the radial and depth distributions of atoms deposited and implanted. The results of the simulation allow us to conclude that the ion beam energy, the mass and fluence of the ions, and especially the target geometry have a noticeable effect on the processes. Experimental data for the depth profiles of atoms implanted and for the thicknesses of films applied are also reported. The variation of the film thickness, the uniformity of the films, and the efficiency of mixing in the film-substrate system are discussed based on the results of simulation and experimental data.

A new type of x-ray refractive lens, the refractive bubbles-in-capillary lens (RBC lens), for plasma diagnostics is presented. The lens consists of a glass capillary filled with a large number of biconcave microlenses. The fabrication technique for the lens is described. It is shown that the microlenses have a spherical shape and can focus x-ray radiation with photon energies E>4 keV. Ray-tracing and analytical calculations of lens properties have been performed and have predicted high efficiency and good spatial resolution for RBC lenses. Real lenses were tested using Cr Kα x-ray radiation (λ=2.29 A), and spatial resolution of about 10 μm was obtained. In plasma experiments, x-ray radiation from a Ti X pinch (λ=2.62 A) was focused by a lens with 35 bubbles in a 100 μm diam capillary (focal length of about 8 cm) to a spot with diameter less than 6 μm. The shape of the hot plasma could be seen. Possibilities for RBC lens applications to plasma measurements are discussed.

A new original approach and an experimental setup were proposed by the authors in order to realize in situ ion implantation and different material layer deposition on metals by the same ion beam. The developed simulation software enabled us to describe ion beam assisted deposition process as well as to calculate radial and depth distribution of deposited/implanted atoms. The simulations yield definite conclusions on influence of ion beam energy, ion mass, fluence and particular geometry of a sputter. Experimental results (RBS) are also presented that made possible to obtain depth distributions of implanted atoms and deposited layer thickness on copper surfaces. The observed variation in thickness of the deposited layers, their uniformity and an efficiency of the layer-substrate intermixing are discussed and interpreted on the basis of both simulation results and experimental data.

A hybrid model, which makes it possible to calculate the influence of the drain voltage and the temperature on the mobility of electrons in the n‐channel of silicon MOS transistors with a high‐alloy substrate in the linear regime of their operation on the basis of a combination of analytical approximations and modeling of electron transfer by the Monte Carlo method, has been proposed.

The results of investigation of optical constant changes for films of polymethylmethacrylate, polystyrene, some of polyimides and industrial positive photoresists irradiated with light ions are presented. It was shown that ion implantation is effective method for modification of optical properties for polymers and that the approach based on molecular refraction changes for chemical bonds permits to forecast the values of refractive indices depending on irradiation doses.

A study of the 150–300 keV proton beam transmission through glass (borosilicate) tapered capillaries with different diameters of the input and output of the capillary was performed. The focusing effect was observed. The areal density of the transmitted beam is enhanced by approximately 20 times. It was shown that changing a taper angle from 0.5 deg to 1.7 deg evidences the increase of the transmission coefficient more than by 300 times keeping the initial energy spectrum of ions.

A new method for producing a compound refractive X-ray lens is described. The lens is designed as glass capillary "lled by a set of concave individual lenses. The method is appropriate for the preparation of 10}1000 spherical lenses in a glass capillary with a diameter of 0.1}1 mm. Lens aberrations are considered and simple formulas for spot size are derived. Ray-tracing simulations on the focusing experiments using 18 keV X-rays are reported. ( 2000 Elsevier Science B.V. All rights reserved.

In this work the cellular structure is proposed as a buffer layer for defect-free heteroepitaxial growth of mismatched materials. The micro-cellular buffers were formed by 80 keV In+ ion implantation into single-crystalline (001) silicon wafers (2 × 1016 cm−2) followed by Q-switched laser annealing at an energy density of about 1.2–3.5 J/cm2. The structure of the obtained surface was investigated by plan-view and cross-section transmission electron microscopy. It has been found that the In-implanted, and subsequently laser annealed, Si surface exhibits a structure consisting of a system of ‘seed’ pads (cells) separated by indium filled trenches (walls of the cell). The linear dimensions of the pads and trenches are measured to be 15–100 and 3–5 nm, respectively, which is close to the optimal values for defect-free epitaxial growth of mismatched materials. The obtained Si〈In〉Si buffer layers were used for heteroepitaxial growth of GaAs films. The density of extended defects in GaAs grown on these buffers was found to be considerably lower as compared to conventional GaAs/Si structures grown at similar conditions.

Composites with carbon nanomaterial fillers are of interest for developing and producing cheap and effective structures for protection different systems from electromagnetic (EM) radiation. By this radiation one means, first of all, background EM noise, emitted by cellphones, microwave ovens, computers, etc. Different shielding efficiency for different purposes is needed. For example, attenuation efficiency more than 30 dB suffices for commercial application, but for military purposes - from 80 to 100 dB is necessary.

The influence of various effects inherent to the high-energy ion bombardment of crystals on the latent track formation is treated. The nature of tracks is dependent on a type of solids. The relaxation of strong electron excitation which occurs under irradiation of materials by energetic ions is the main parameter which defines the nature of track regions. The track migration of implanted atoms as well as track channeling of incident ions is discussed for ion implantation in semiconductors.

Although the field of ion beam synthesis of buried dielectric layers in silicon received much attention in the 1980s, specific details of the process still remain that need to be clarified and reconsidered in order to utilize the technique to its fullest advantage. This research attempts (i) to outline the implantation conditions that minimize the damage in the silicon surface layer of substrates incorporating buried layers of either SiO 2 or Si 3 N 4 , and (ii) to explore the possibility of directly creating buried layers of Si 3 N 4 . In order to have useful single crystal silicon on the top of the buried layer, it is necessary to conduct implants at elevated substrate temperatures and to employ sample preheating from an external heat source independent of the ion beam. The use of high intensity nitrogen implantation looks like a promising approach which enables the synthesis of continuous layers of stoichiometric Si 3 N 4 in situ . Combined analysis methods including RBS, RHEED and THEED are used to characterize the resulting as-implanted structures.

The effect of channeling of high energy ions through latent tracks in solids is described theoretically by means of transport equations. It is shown that deep tails in implanted impurity and radiation damage depth distributions by high energy ion implantation can be explained by this effect. The experimental data obtained for silicon and diamond implanted with high energy Ni, Kr, and Xe ions are compared with theoretical predictions.

A method of the formation of device isolation in III–V semiconductors is considered. The method is based on the creation of a uniform concentration of radiation defects by polyenergetic ion implantation. A numerical model as well as a computer program have been developed which enabled us to find optimal energy and dose sets for polyenergetic ion implantation, necessary to form high-quality insulating layers. Experiments on the formation of isolation in GaAs have been carried out. The electric properties and the thermal stability of the implanted regions have been investigated.

A study is made of transmission of straight and curved thin-film gamma-waveguides. It is shown that in curved waveguides maintaining the limited number of waveguide modes a radiation flux may be appreciably attenuated due to radiation of photons into the medium surrounding a waveguide.

Compound refractive X-ray lens, consisting of a lot number of placed in-line concave microlenses, is a unique device to control X-ray beams. It works like ordinary refractive lens for visual light and, in contrast to other X-ray optical devices, is useful for forming image of X-ray source. The size of the source image S1 depends on the distance a between the source and the lens and may be calculated as S1=S M, where S is source size, M- magnification. The magnification M depends on a and b as M=b/a, where b is distance from the lens to the source image. This distance b satisfies to a well-known lens formula 1/a+1/b=1/f, where f is lens focal length. This lens property may be used for forming small-sized X-ray spots at a large enough distances from the lens. Such beams are of great interest for experiments on SAXS and X-ray diffraction. Here we report results of our first experiments in Istituto per lo Studio dei Materiali Nanostrutturati and Laboratori Nazionali di Frascati on using compound refractive X-ray lenses for forming X-ray beams.

The possibility of obtaining x-ray microbeams with a prescribed intensity using a system containing a x-ray tube with a transmission thin-film anode and a tapered glass microcapillary is investigated.

We have fabricated and tested short focal-length compound refractive lenses for X-rays (CRLs) and considered its application for focusing coherent beams. The lens is designed in the form of glass capillary filled by micro-air-bubbles embedded into epoxy. The interface between the bubbles formed 90 to 196 spherical bi-concave microlenses with curvature radius equals to the capillary one. When compared with CRLs manufactured using other methods, the micro-bubble lenses have shorter focal lengths with higher transmission for moderate energy X-rays (e.g. 7 - 12 keV). The lenses are inexpensive and are ideally suited for focusing X-rays generated by high power single pulsed operation coherent X-ray sources with Source size 50-100 microns. We used beamline 2-3 at the Stanford Synchrotron Radiation Laboratory (SSRL) to measure focal lengths between 100-150 mm and absorption apertures between 90 to 120 pm. Transmission profiles were measured giving, for example, a peak transmission of 27 % for a 130-mm focal length CRL at 8 keV. The focal-spot sizes were also measured yielding, for example, an elliptical spot of 5 × 14-μm2 resulting from an approximate 80-fold demagnification of the 0.44 × 1.7 mm2 source.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We have fabricated and tested short focal-length compound refractive lenses (CRLs) composed of micro-bubbles embedded in epoxy. The bubbles were formed in epoxy inside glass capillaries. The interface between the bubbles formed 90 to 196 spherical bi-concave microlenses reducing the overall focal length inversely by the number of lenses. When compared with CRLs manufactured using other methods, the micro-bubble lenses have shorter focal lengths, better imaging, and focusing qualities with higher transmissions and gains for moderate energy x-rays (e.g. 7 - 12 keV). We used beamline 2-3 at the Stanford Synchrotron Radiation Laboratory (SSRL) to measure focal lengths between 100-150 mm and absorption apertures between 90 to 120 μm. Transmission profiles were measured giving, for example, a peak transmission of 27 % for a 130-mm focal length CRL at 8 keV. The focal-spot sizes were also measured yielding, for example, an elliptical spot of 5 x 14-μm 2 resulting from an approximate 80-fold demagnification of the 0.44 x 1.7 mm 2 source. The measured gains in intensity over that of unfocused beam were between 9 and 26. Theoretical gain calculations that include spherical aberrations show that these values are reasonable. The micro-bubble technique opens a new opportunity for designing lenses in the 8-9 keV range with focal lengths less than 30-40 mm.

We developed and studied refracting microcapillary lens for x-ray photons with energy 5.4 keV. This lens is a glass capillary wiht a central channel filled with a number of concave microlenses. The lenses are made by injection compressed air into a capillary channel, previously filled by liquid polymer. The images of 20-100μm width slits are obtained. A good agreement is seen betweenthe image and slits sizes. Ray tracing calculations of iamge formation are made. Experimental and calculated results are in a good agreement.

Refractive microcapillary lens for hard x-rays is presented. The lens is designed as glass capillary filled by a large number of biconcave microlenses. Fabrication technique for the lens is described. It is shown that the the microlenses have a spherical shape. The spherical aberrations of the lens are calculated. The possibility of production of micrometer sized x-ray beams by using the microcapillary x-ray lens is discussed.