... Title : AN OPTIMIZED METHOD FOR CORRECTING FOR SMEARING ABERRATIONS: COMPLEX X-RAY SPECTRA. Corporate ...

The aberration of a multipole Wien filter for energy-filtered x-ray photoemission electron microscopy was analyzed and the optimized Fourier components of the electric and magnetic fields for the third-order aperture aberration corrections were obtained. It was found that the third-order aperture ...

A method is described to make zone plates with high zone numbers (N or equal to 1,000) using laser interferences in combination with photoresist layers. By focusing soft X-rays with such zone plates, spherical aberration occurs. This can be corrected if o...

Chemical mapping at atomic-column resolution by energy-dispersive x-ray spectroscopy in a spherical aberration-corrected scanning transmission electron microscope (STEM) has been demonstrated for the 1.47-A dumbbell structure in InGaAs. The structural imaging and the chemical information in the two-dimensional map are directly correlated. Comparisons with ...

Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for ir...

A new ultrahigh-resolution photoemission electron microscope called PEEM3 is being developed and built at the Advanced Light Source (ALS). An electron mirror combined with a much-simplified magnetic dipole separator is to be used to provide simultaneous correction of spherical and chromatic aberrations. It is installed on an elliptically polarized ...

A new ultrahigh-resolution photoemission electron microscope called PEEM3 is being developed and built at the Advanced Light Source (ALS). An electron mirror combined with a much-simplified magnetic dipole separator is to be used to provide simultaneous correction of spherical and chromatic aberrations. It is installed on an elliptically polarized ...

A new ultrahigh-resolution photoemission electron microscope called PEEM3 is being developed and built at the Advanced Light Source (ALS). An electron mirror combined with a much-simplified magnetic dipole separator is to be used to provide simultaneous c...

A refractive x-ray lens was characterized using a magnifying cone beam setup for differential phase contrast imaging in combination with a microfocus x-ray tube. Thereby, the differential and the total phase shift of x rays transmitted through the lens were determined. Lens aberrations have ...

A refractive x-ray lens was characterized using a magnifying cone beam setup for differential phase contrast imaging in combination with a microfocus x-ray tube. Thereby, the differential and the total phase shift of x rays transmitted through the lens were determined. Lens aberrations have ...

An optical system for X-ray microfocusing that consists of a pair of spherical mirrors has been developed. In grazing incidence optics with spherical (cylindrical) mirrors, focused beam size is generally restricted by spherical aberration. However, the spherical aberration can be corrected by the sequential reflection of two spherical ...

Alternate configurations for a two-channel three-mirror glancing incidence X-ray telescope have been designed and evaluated. A Wolter-Schwarzschild type I telescope is used as a base system for one channel of operation. The second channel consists of the secondary mirror of the Wolter-Schwarzschild type I telescope used as a primary mirror and a third aspheric mirror as a ...

Fresnel zone plate patterns, free of spherical aberration, with diameters of up to 0.63 mm and linewidths as small as 1000 A were fabricated on polyimide membrane x-ray masks using scanning electron beam lithography. Distortion of the electron beam scan raster was reduced to < or =2500 A over a 2 x 2 mm field by applying deflection ...

Design and experience of the initial operation of a new beamline (BL-16) for a 3.6-m-long, 53-pole wiggler/undulator constructed at the Photon Factory are described. The insertion device has hybrid permanent magnets with a period of 12 cm and a maximum magnetic field of 1.47 T. In the undulator mode, the energy of the fundamental peak can be varied from 40 to 400 eV. In the wiggler mode, an x-ray ...

... Accession Number : AD0666713. Title : USE OF CHROMOSOME ABERRATIONS TO ESTIMATE X-RAY AND GAMMA-RAY DOSE TO MAN. ...

... Descriptors : *X RAYS, *ANTHROPOMETRY, ALGORITHMS, ERROR ANALYSIS ... CONVERTERS, ERROR CORRECTION CODES, BIODYNAMICS. ...

SCANNING ELECTRON MICROSCOPY (SEM) - ENERGY DISPERSIVE X-RAY. SPECTROSCOPY (EDX) - X-RAY FLUORESENCE SPECTROSCOPY (XRF) - GAS ...

An in-vacuum double-phase-plate diffractometer for performing polarization scans combined with resonant X-ray diffraction experiments is presented. The use of two phase plates enables the correction of some of the aberration effects owing to the divergence of the beam and its energy spread. A higher rate of rotated polarization is thus ...

Quantized x-ray phase vortices, namely, screw-type topological defects in the wave fronts of a coherent monochromatic scalar x-ray wave field, may be spontaneously nucleated by x-ray lenses. Phase retrieval is used to reconstruct the phase and amplitude of the complex disturbance created by aberrated gold nanolenses illuminated with ...

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is illustrated with optical design of a model spectrometer to deliver a resolving power above 20400 at a photon energy of 930?eV (Cu L-edge). With this energy taken ...

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry. The analysis is illustrated with optical design of a model spectrometer to deliver a resolving power above 20400 at a photon energy of 930?eV (Cu L-edge). With this energy taken ...

Focusing performance of cylindrically bent crystal in symmetric Bragg back diffraction geometry was investigated theoretically and simulated numerically. A thin flat crystal was introduced into the setup to separate focal spot from the incident beam. It was shown that in order to achieve an ideal focusing with strongly bent crystal the shape of the crystal surface has to be aspherical. A ...

We report the impact of an elliptical, high resolution zone plate on the performance of an initially astigmatic soft x-ray scanning photoemission microscope. A zone plate with carefully calibrated eccentricity has been used to eliminate astigmatism arising from transport optics, and an improvement of about a factor of 3 in spatial resolution was achieved. The resolution is ...

... standard error or confidence range of the RBE. Chromosome Aberrations in Human Lymphocytes 1. Reciprocal translocations Item 6 refers to seven studies ... ...

Hard X-rays have exceptional properties that are useful in the chemical, elemental and structure analysis of matter. Although single-nanometre resolutions in various hard-X-ray analytical methods are theoretically possible with a focused hard-X-ray beam, fabrication of the focusing optics remains the main hurdle. ...

Ultrasoft X-rays have been shown to be very efficient in inducing chromosomal aberrations in mammalian cells. The present study was aimed to evaluate the modifying effects of DMSO (a potent scavenger of free radicals) on the frequencies of chromosome aberrations induced by soft X-rays. Confluent held G1 Chinese ...

The effect of abberations on the resolution of x-ray holography should be estimated while the conditions for the elimination of aberrations can not be fulfilled. An analysis to wave aberrations and ray aberations in in-line x-ray holography is given. All ...

The four Constellation-X Spectroscopy X-ray Telescopes require four sets of 2,600 thin mirror segments be supported with minimum deformation and aligned with arc-second level accuracy. We have developed a support and alignment system that minimizes segment deformation and allows the mirror segments to be made confocal. This system relies upon a set of five mirror support ...

Current trends in the development of active optics methods are reviewed. These methods allow generating smooth optical surfaces by either in-situ stressing or stress figuring. Such surfaces are free from ripple errors - i.e. high spatial frequency errors - and thus are useful to achieve high angular resolution and high contrast imaging in astronomy. Interferometric results of many cases from ...

The angular resolution of Chandra is close to the practical limit of grazing incidence telescopes due to the difficulty of imparting an accurate figure and smooth surface to mirror substrates whose physical area is over two orders of magnitude larger than their effective area. However, important scientific objectives lie beyond the reach of Chandra and all future missions being planned by the ...

A novel instrument for imaging ESCA is described. It is based on a tandem arrangement of two hemispherical energy analysers used as an imaging energy filter. The main spherical aberration (?2-term) of the analyser is corrected by the antisymmetry of the tandem configuration. The kinetic energy range useable for imaging extends up to 1.6 keV this is ...

... an index of refraction of n=1.62 Using the relation t=x/v for the two mediums yields a correction of t=10.7ns. ... 4. X-ray Delay Corrections ...

The design of current X-ray telescope systems needs to reach a compromise between the resolution and sensitivity. A new area of interest of adaptive optics is the development of actively controlled thin X-ray mirrors, where aberrations would be corrected. Their assembly on an X-ray telescope would provide an ...

It is well known that normal incidence, aplanatic telescope designs performed better at low field angles than ones corrected only for spherical aberration. This is why most large astronomical telescopes fabricated in the past fifty years have been of the Ritchey-Chretien design rather than of the classical Cassegrain design. For the relatively new field of ...

In this case, CGH fabrication errors or systematic piston error along the optical axis could mix with the conic or spherical aberration present in the mirror. Rather ...

... In the present study, the yield of aberrant chromosome segregation in human ... obtained in hamster cells (22) and the results of the present study have ... ...

Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray--induced lesions in Down cells have been offered. It is shown here that the repair of the DNA ...

Unstimulated lymphocytes from individuals with Down Syndrome (trisomy 21) are more sensitive to the induction of dicentric and ring aberrations by X rays than normal lymphocytes. Several explanations involving the more rapid rejoining of X-ray-induced lesions in Down cells have been offered. It is shown here that the repair of the DNA ...

A decrease in the yield of chromosomal aberrations in root meristems of wheat induced by four different doses of x rays has been found to occur when the seeds are pretreated with ultraviolet radiation. However, in X/sub 2/ generation, the mutation rate for combined treatment is lower than for x ...

If groups of broad-bean roots are treated with x rays or by immersion in triethylene melamine solution and if the doses are adjusted so that the subsequent reduction in growth is equal, the cells of the root-tips carry equal numbers of chromosome aberrations. This had previously been shown when x ...

A compound x-ray imaging device has been developed as an aid in the diagnostics of a laser-fusion process which involves a pellet about 100 microns in diameter. The formation of images using x-rays is replete with geometrical aberrations among which are s...

... surface membrane to correct for aberrations. ... less curvature results in less aberration. ... a negative conic constant helps reduce spherical aberration. ...

The frequency of chromosome aberrations in lymphocytes taken from the peripheral blood provides a useful measure of absorbed dose. The estimation of dose is affected by time in culture of the lymphocytes, by sampling error and sampling time, and by size, ...

Results are reported from a study of the effects of nitric oxide concentration on the radiosensitivity of root tips of the broad bean, Vicia faba, as demonstrated by chromosomal aberrations. (C.H.)

The effect of carbon dioxide on radiation-induced chromosome aberrations was investigated to determine its relation to dose rate and the efficacy of a pretreatment followed by x irradiation in nitrogen or in vacuo. Carbon dioxide and air, present during the radiation treatment, significantly increase the frequency of chromosome aberrations ...

The effect of CO/sub 2/ on radiation-induced chromosome aberrations was investigated to determine the relation of this agent to dose rate and the efficacy of a pretreatment followed by x irradiation in N or in vacuo. Carbon dioxide and air, present during the radiation treatment, significantly increase the frequency of chromosome aberrations ...

Adaptive optics were proposed as a solution to heat load problems generated by powerful x-ray beams of next generation synchrotron radiation sources. A first adaptive x-ray mirror prototype is presently under design at the ESRF. This device, which is optimized for a wiggler beamline, is described here. It is composed of three main subsystems: the mirror ...

An on-line correction technique was developed for the conversion of electron probe X-ray intensities

... the size of the 7r* peak in the carbon K edge absorption spectrum), and ... to the correct value [1-3]. Grazing incidence x-ray reflectivity measurements ...

Two operationally independent programs, A637 and A638, replace manual measurements of peak positions on strip charts from X-ray diffractometers and simultaneously make data corrections and supply measurements previously not available. Processed digitized ...

Beam hardening (BH), caused by the energy dependence of x-ray attenuation in materials, reduces the reliability of images generated by computed tomographic (CT) when polychromatic x-ray sources are used. The magnitude of the BH effect was calculated, and ...

... F or G ratio in lymphocytes exposed to neutrons or X rays, while again a significantly higher fraction of complex- ... condensed chromosomes for heavy ions and metaphase for X rays is correct and ... also...

Dec 8, 2006 ... They identify 220 X-ray sources with catalogued stars down to V = 17, ... systematic corrections of 0.3" and 1.75" in RA and declination, ...

The aim of the report is to investigate various types of ionization chamber suitable for the measurement of absorbed dose to water for medium energy X-rays. The chamber correction factors to be applied to an ionization chamber calibrated in terms of air k...

Jun 9, 2011... spectral energy distribution and the near-infrared color-color region. ... The logarithm of the intrinsic (absorption-corrected) total-band X-ray ...

... The goal was to investigate methods to correct aberrations in the ... with entrapped non-neutral electron distributions to correct spherical aberration. ...

... Accession Number : ADA319052. Title : Demonstrating Optical Aberration Correction With a Mems Micro-Mirror Device. ...

... Accession Number : ADA800275. Title : Correction of Spherical Aberration by a Phased Line Source. Corporate Author : AIR ...

By use of a focusing configuration analogous to a Gregorian or a Cassegrain telescope, the on-axis aberration of a grazing-incidence spheric-based Kirkpatrick-Baez compound microscope may be precisely corrected. For finite fields, the off-axis performance degrades too rapidly for high-spatial-resolution imaging of even the smallest objects of interest. ...

The relationship between the dose of x rays and the frequency of two-hit chromosome aberrations in the Allium cepa root tip was explored. The relationship between the x-ray dose and anaphase brldges was found to be linear. The relationship between the dose of x rays and metaphase rings ...

Microoptical systems with clear aperture of about one millimeter or less are fabricated from a layer of photoresist using a lithographic process to define the optical elements. A deep X-ray source is typically used to expose the photoresist. Exposure and development of the photoresist layer can produce planar, cylindrical, and radially symmetric micro-scale optical elements, ...

We present an investigation of the morphology and composition of novel types of axial nanowire heterostructures where Ga(x)In(1-x)As is used as barrier material in InAs nanowires. Using aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray analysis we demonstrate that it is possible to grow junctions by changing the ...

In order to understand the mechanism of Cu clustering and Ni effects on Cu clusters, a sub-nano scale structural and elemental analysis of Cu-bearing steels was carried out through an aberration corrected scanning transmission electron microscope. Based on systematic observation condition adjustment by changing the electron scattered angle, we adopted an ...

The technique of X-ray energy dispersive spectroscopy (XEDS) spectrum imaging in a dedicated scanning transmission electron microscope (STEM) is discussed in relation to its applicability to bimetallic nanoparticles. It is shown that the recent availability of aberration corrected microscopes and multivariate statistical analysis (MSA) techniques has ...

Nanofocusing refractive x-ray lenses (NFLs) form the basis of a hard x-ray scanning microscope. They are characterized by their short focal length (~ 10 mm at 15 keV to 25 keV) and large numerical aperture, allowing for the generation of hard x-ray nanobeams even at short distances from a synchrotron radiation source. These optics, ...

In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a lens the resolution is limited, in principle, only by the largest scattering angles recorded. However, the imaging task ...

For an exact solution of the Bragg equation it is necessary that there be a one-to-one correspondence (equivalence) between the angnlar measure theta and the wavelength measure lambda . Because the aberrations inherent in all x- ray diffraction profile measurements distont the profile, it is necessary to ...

). The method is also applicable to exploration geochemistry (Kunzendorf, 1972). Characteristic X-rays from and stay in turn be used to correct characteristic X-ray intensities (Anderaan and Keep, 1958 yields in the region of interest characteristic K X-rays of the elements K, Ca, Ti, V, Cr, Mn, Fe� Hi. Cu

High speed, high x-ray energy imaging of implosions is a key diagnostic technique in the glass laser implosion program in the USA. With the correct x-ray energy, time gated images can measure the symmetry and mix of the imploding shell into the stagnated ...

X-ray reflectivity has been used to nondestructively measure the density of thin, porous, SiO2-based xerogels. Critical angle, defined by total external reflection, was measured for multiple x-ray energies to correct for sample misalignment error in me determination of the densit...

Following reports of renewed activity of the transient neutron star low-mass X-ray binary SAX J1806.5-2215 (ATel #3193), we obtained a ~1 ks Swift/XRT pointing of the source field on 2011 March 1. The observation was carried out in the PC mode and reveals one relatively bright X-ray source within the XRT field of view. For this object, we find an ...

The absolute intensities of the K? and K? X-rays produced by 29 keV electrons incident on a thick Ag target at forward angles in the range 0� to 55� relative to incident electrons have been measured. When corrections are made for attenuation within the target material, the results indicate that the K-shell X-rays are emitted ...

A scanning transmission electron microscope (STEM) equipped with an x-ray energy dispersive spectrometer (EDS) was used for quantitative x-ray microanalysis of an MgO-10 mol% NiO ceramic. Using the Cliff-Lorimer standardless ratio technique for quantitative x-ray microanalysis, absorption of the Mg characteristic x ...

The effects of subjecting dry seeds of bread wheat to combined and separate treatments of ultraviolet and x rays on the frequency of chromosome aberrations, and the rate and spectrum of mutations were studied. Somatic chromosome aberration frequency was found to increase with dose in x-ray treatments. ...

Measuring the deviation of a wavefront from a sphere provides valuable feedback on lens alignment and manufacturing errors. We demonstrate that these aberrations can be accurately measured at hard x-ray wavelengths, from far-field intensity measurements, using phase retrieval with a moveable structure in the beam path. We induce ...