Energy Technology Data Exchange (ETDEWEB)

The proposed short wavelength coherent light source driven by the SLAC 3 km linac might be used to induce transitions between nuclear isomeric states. If an isotope were found with energetically adjacent isomeric states, one short-lived and one long-lived, and it were possible to separate and concentrate the long-lived species, and other nuclear and solid-state parameters were favorable, it might be possible to convert sufficient population to the short-lived state to realize {gamma}-ray lasing. Even if the x-ray intensity were insufficient, study of such driven transitions would be quite valuable.

International Nuclear Information System (INIS)

Coherent x-ray production by a seeded free electron laser (FEL) is important for next generation synchrotron light sources. The authors examine the feasibility and features of FEL emission seeded by a high-order harmonic generation (HHG) of an infrared laser. In addition to the intrinsic FEL chirp, the longitudinal profile and spectral bandwidth of the HHG seed are modified significantly by the FEL interaction well before saturation. This smears out the original attosecond pulselet structure. The authors introduce criteria for this smearing effect on the pulselet and the stretching effect on the entire pulse. They discuss the noise issue in such a seeded FEL.

CERN Document Server

We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at 1.7 <= z <= 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray weak, non-BAL QSOs and find that such objects are rare; for example, sources underluminous by a factor of 10 comprise $\\la$2% of optically-selected SDSS QSOs. X-ray luminosities vary with respect to UV emission by a factor of $\\la$2 over several years for most sources. UV continuum reddening and the presence of narrow-line absorbing systems are not strongly associated with X-ray weakness in our sample. X-ray brightness is significantly correlated with UV emission line properties, so that relatively ...

Energy Technology Data Exchange (ETDEWEB)

Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.

Energy Technology Data Exchange (ETDEWEB)

A brilliant X ray source is proposed for lithography instruments with use of a multi-mirror system. The inverse Compton scattering between the stored electron beam in the storage ring and the stored photon beam in the multi-mirror system, is applied for the X-ray generation. (author)

Energy Technology Data Exchange (ETDEWEB)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

CERN Document Server

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are ...

International Nuclear Information System (INIS)

The quantitative imaging of a phase object using 16 keV x-rays is reported. The theoretical basis of the techniques is presented along with its implementation using a synchrotron x-ray source. It is found that the phase image is in quantitative agreement with independent measurements of the object. 13 refs., 5 figs.

International Nuclear Information System (INIS)

Determination of Mn, Fe, Ni, Cu, Zn, and Pb in human soft tissues by radionuclide X-ray fluorescence analysis (using "2"3"8Pu and "1"0"9Cd sources) is described. The results of multielement XRS analysis of selected human tissues are tabulated. They are in good agreement with the literature data. It is concluded that X-ray fluorescence technique is a suitable method for trace element determination. (author).

International Nuclear Information System (INIS)

An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption profiles of bulk samples. Tomographic reconstruction yields quantitative three-dimensional maps of the X-ray refractive index and of the attenuation coefficient, with a spatial resolution down to a few microns. The method is mechanically robust, it requires little monochromaticity, and can be scaled up to large fields of view. These are important prerequisites for use with laboratory X-ray sources. Numerous applications ranging from wave front sensing to medical radiography are presently under investigation.

Energy Technology Data Exchange (ETDEWEB)

Considering the hardware characteristics of the laser-induced plasma X-ray source and the limitations of the conventional cone-beam reconstruction algorithm, a general cone-beam reconstruction algorithm has been developed at our laboratory, in which the motion locus of the X-ray source is an arbitrary curve corresponding to at least a 2{pi} continuous horizontal angular displacement in the coordinate system of the specimen. The preliminary simulation shows that the general cone-beam reconstruction algorithm consistently results in visually satisfactory images.

International Nuclear Information System (INIS)

The physical foundations are described of radionuclide X-ray fluorescence analysis (RXFA) and the table shows the values of K- and L-absorption thresholds and the K- and L-line energies of elements. The calculation of the intensity of characteristic radiation during RXFA proceeds from relations derived for conventional X-ray fluorescence analysis. The choice of the radionuclide source is ruled by the nature of the analysed substance and the used detection technique. The diagram shows the areas of radionuclide sources and the energy of the fluorescence radiation of elements. The table shows the spectra of radionuclide sources suitable for the purposes of RXFA measured by semiconductor Si(Li) and Ge(Li) detectors. (ES).

International Nuclear Information System (INIS)

TlGaSe_2 compound belongs to group of layered semiconductors of A"3B"3C_2"6-type. Photoelectric and optical properties of TlGaSe_2 single crystals were investigated in detail. Influence of gamma-, electron and neutron radiation on photoelectric properties of TlGaSe_2 single crystals is investigated too. The present work deals with experimental results relative to X-ray dosimetric characteristics of TlGaSe_2 crystals at 300 K. X-ray conductivity and X-ray dosimetric characteristic measurements are carried out in low load resistance regime. The source of X-ray radiation is the installation of X-ray diffraction analysis (URS-55a) with the BCV-2(Cu). Intensity of X-ray radiation (E) is regulated by measurement with current variation in tube at each given value of X-ray radiation dose E (R/min) are measured by crystal ...

Energy Technology Data Exchange (ETDEWEB)

A portable X-ray image system is described comprising: (a) a base assembly including panels and hinges joining the panels together along edges, and compression stops for biasing the hinges to compensate for the weight of payload when mounted on the base assembly, the compression stops being located for interaction with the hinges for biasing the panels to exhibit upward bowing when laid upon a flat surface prior to loading, and to provide resiliency for facilitating the base assembly assuming a substantially flat configuration when a predetermined payload is placed upon the base assembly; (b) an X-ray member; (c) apparatus for detachably mounting a table member to the base assembly to hold the table member at a location above the base; (d) an X-ray source; (e) means for sensing X-rays to form an image; (f) means for mounting the X-ray source ...

Energy Technology Data Exchange (ETDEWEB)

A method has been developed to optimize the energy resolution of a horizontally focusing monochromator. The method consists of determining the optimum radius of curvature of the cylindrically bent monochromator crystal by minimizing the total diffracted X-ray flux measured through an X-ray absorption foil. When measured at an absorption edge a global minimum can be identified, which corresponds to the minimum energy band accepted along the entire length of the crystal. Experimental verification of this method has been validated by comparing X-ray fluorescent scans taken for a series of crystal curvatures and by directly measuring the X-ray beam profiles at the corresponding points. The actual optical configuration and asymmetric-cut parameter of the focusing monochromator on beamline X4C at the National Synchrotron Light Source are modeled and ray tracing simulations of the optical ...

International Nuclear Information System (INIS)

Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the ...

Science.gov (United States)

The {ital L}{sub 2}-{ital L}{sub 3} Coster-Kronig transition probability ({ital f}{sub 23}) in Tm was measured by multiparameter {ital K} versus {ital L} x-ray coincidence techniques. The Tm x rays were obtained from a radioactive source of {sup 169}Yb and were detected with cooled germanium and silicon detectors of high-energy resolution. Corrections were applied for the contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak and for the contribution of unresolved {ital L}{eta} x rays to the {ital L}{alpha}{sub 1,2} x-ray peak. The contribution of {ital K}{alpha}{sub 1} x rays to the {ital K}{alpha}{sub 2} x-ray peak was determined solely from the results of the coincidence measurements ...

British Library Electronic Table of Contents (United Kingdom)

The use of X-ray scattering techniques in pharmaceutical science is increasing, in part through increased collaborations with the materials science community, and through increased availability of instrumentation, particularly synchrotron sources. The ability to understand not only the biopharmaceutical outcome, but also arguably, more importantly, the structural aspects of drugs and drug delivery systems, is essential to progressing pharmaceutical science; this review serves as an introduction to the major techniques and the wide range of areas in which X-ray scattering may be applied in understanding and controlling structure in pharmaceutical systems.

CERN Document Server

The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. The 0.2-100keV ...

International Nuclear Information System (INIS)

The time and dose characteristics of the electron and X-ray radiations of a tube, connected to a subnanosecond mega volt accelerator, are measured. By the pulse of the accelerating voltage of #>=# 600 kV with duration of #approx =# 0.3 ns the tube generates approximately 5 x 10"1"2 electrons pulse. The current amplitude equals approximately 5 kA/pulse and the radiation dose-about 5 kGy/pulse. The X-ray radiation dose from the tantalum external target constitutes 0.15 Gy/pulse. The prototypes of the electron and X-ray tubes sufficiently lower volumes, opening new applications in the technique and medicine, are developed

International Nuclear Information System (INIS)

The X-ray intensity ratio K_#beta#/K_#alpha# has been measured by using a 10 mCi "5"5Fe source (Mn K X-rays) and high resolution Si(Li) detector system coupled to a computer-controlled multichannel analyzer over the range of 15#<=#Z#<=#22. Correction have been made to the measured relative intensities (K_#alpha# and K_#beta# X-rays) for self-absorption in the sample, air, Be-window absorption and detection efficiency. The results are compared with those of other experiments and with the Scofield calculations. (author) 13 refs.; 3 figs.; 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

A convolution/superposition method is proposed for use with primary and scatter dose kernels formed for energy bins of X-ray spectra reconstructed as a function of off-axis distance. It should be noted that the number of energy bins is usually about ten, and that the reconstructed X-ray spectra can reasonably be applied to media with a wide range of effective Z numbers, ranging from water to lead. The study was carried out for 10-MV X-ray doses in water and thorax-like phantoms with the use of open-jaw-collimated fields. The dose calculations were made separately for primary, scatter, and electron contamination dose components, for which we used two extended radiation sources: one was on the X-ray target and the other on the flattening filter. To calculate the in-air beam intensities at po...

International Nuclear Information System (INIS)

The feasibility was studied of the application of radionuclide X-ray fluorescence analysis to the identification and determination of chemical elements in the air. A description of the method is presented, the main stages of the analysis are discussed (sample preparation and standards, selection of radioactive radiation sources, geometry of measurement and evaluation of results). The method is illustrated on the determination of elements Fe, Cu, Zn, Br, and Pb in air samples taken in the city of Prague. (author) 2 tabs., 2 figs., 14 refs.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method was used for the determination of Fe and Zn in healing plants (Sage, Peppermint, Stinging, Common Agrimony, Milfoil, Ribwort, Tansy, White Dead-Nettle). "2"3"8Pu exciting source and Si/Li semiconductor detector were used for the determination. (author)

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and "2"3"8Pu exciting source was used for the determination of Cu, Ni, Pb, and Zn in soil samples from various localities near the D-61 Bratislava-Trnava highway (CSFR). (author) 1 ref.; 1 tab.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

CERN Document Server

Context. The high energies of protostellar jets, implied by recent observations of X-rays from such flows, came very much as a surprise. Inferred shock velocities are considerably higher than what was previously known, hence putting even larger energy demands on the driving sources of the jets. The statistics of X-ray emitting jets are still poor, yet a few cases exist which seem to imply a correlation between the presence of HeI 1.0830 mu emission and X-ray radiation in a given source. Aims. This tentative correlation needs confirmation and explanation. If the jet regions of HeI 1.0830 mu emission are closely associated with those producing X-rays, high resolution infared spectroscopy can be used to observationally study the velocity fields in the hot plasma regions of the jets. This would provide the necessary evidence to test and further develop theoretical ...

Energy Technology Data Exchange (ETDEWEB)

An atom-by-atom understanding of life processes is emerging from a flurry of experiments fueled by synchrotron sources and DNA technology. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}.

Energy Technology Data Exchange (ETDEWEB)

This Final Report documents the research accomplishments achieved in the first phase of operations of a new Advanced Photon Source beam line (7-ID MHATT-CAT) dedicated to real-time x-ray studies. The period covered by this report covers the establishment of a world-class facility for time-dependent x-ray studies of materials. During this period many new and innovative research programs were initiated at Sector 7 with support of this grant, most notably using a combination of ultrafast lasers and pulsed synchrotron radiation. This work initiated a new frontier of materials research: namely, the study of the dynamics of materials under extreme conditions of high intensity impulsive laser irradiation.

International Nuclear Information System (INIS)

Tl(InS_2)_1_-_x(FeSe_2)_x single crystals (where x=0; 0.001; 0.005; 0.01 and 0.015) were grown by the Bridgman-Stockbarger method. Obtained single crystals were crystallized in monoclinic structure. The present paper deals with experimental results relative to X-ray dosimetric characteristics of the Tl(InS_2)_1_-_x(FeSe_2)_x solid solutions at 300 K. Installation URS-55a was the source of radiation. X-ray radiation dose (E) falling on the crystals is measured by the crystalline X-ray dosimeter DRGZ-02. The value of X-ray conductivity coefficient K_#sigma# characterising X-ray sensitivity is defined as K_#sigma#= (#sigma#_E-#sigma#_0)/E#sigma#_0. where #sigma#_E is conductivity under the effect of X-ray radiation by intensity E, #sigma#_0 is conductivity in the lack of radiation. Comparing X-ray dosimetric characteristics ...

CERN Document Server

We review X-ray plasma diagnostics based on the line ratios of He-like ions. Triplet/singlet line intensities can be used to determine electronic temperature and density, and were first developed for the study of the solar corona. Since the launches of the X-ray satellites Chandra and XMM-Newton, these diagnostics have been extended and used (from CV to Si XIII) for a wide variety of astrophysical plasmas such as stellar coronae, supernova remnants, solar system objects, active galactic nuclei, and X-ray binaries. Moreover, the intensities of He-like ions can be used to determine the ionization process(es) at work, as well as the distance between the X-ray plasma and the UV emission source for example in hot stars. In the near future thanks to the next generation of X-ray satellites (e.g., Astro-H and IXO), higher-Z He-like lines (e.g., iron) will be resolved, ...

Energy Technology Data Exchange (ETDEWEB)

The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment. (authors)

Science.gov (United States)

The Micro-X instrument is a NASA funded, rocket borne X-ray imaging spectrometer planned for launch in January 2011. An array of Transition Edge Sensors (TESs) will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. This will be a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat sink, and will be read out by a SQUID time division multiplexer. X-rays will be focused onto the TES array of 128 pixels on a 600 micron pitch by a conically approximated Wolter optic with an effective area of 200 cm2. The spectrometer will have a field of view of 11.8 arcmin. We describe the design and development progress of the instrument.

Energy Technology Data Exchange (ETDEWEB)

A technique is proposed to generate electron beam with ultralow transverse emittance through laser assisted transverse-to-longitudinal emittance exchange. In the scheme a laser operating in the TEM10 mode is used to interact with the electron beam in a dispersive region and to initiate the emittance exchange. It is shown that with the proposed technique one can significantly downsize an x-ray free electron laser (FEL), which may greatly extend the availability of these light sources. A hard x-ray FEL operating at 1.5 {angstrom} with a saturation length within 30 meters using a 3.8 GeV electron beam is shown to be practically feasible.

International Nuclear Information System (INIS)

Stimulated bremsstrahlung in an undulating electric field in the lasing beam direction (electric wiggler) was shown to be possible from the quantum- mechanical viewpoint. Herein, this possibility is scrutinized from the viewpoint of classical electrodynamics. It is found that if stimulated bremsstrahlung in a transverse undulating magnetic field (magnetic wiggler) occurs, stimulated bremsstrahlung in the electric wiggler must also occur. We further show that a free electron laser (FEL) using a magnetic wiggler to provide a catalyzer field for stimulated bremsstrahlung cannot serve as a practical FEL operating in the soft x-ray region from both theoretical and experimental viewpoints. On the other hand, the authors demonstrate that the FEL using a traveling wake field in a two-beam elliptical pill-box cavity is well suited as a source of coherent radiation in the soft x-ray region.

Energy Technology Data Exchange (ETDEWEB)

A micropositioning stage for use with an x-ray microscope has been developed to scan samples over a 100 {mu}m{times}100-{mu}m area with a resolution of 100 A. The stage employs flexure hinges driven by piezoelectric actuators to achieve this high positioning accuracy. Due to the severe geometry of the hinges, stresses and deflections are determined (via finite element methods) to ensure a credible design. Since the stage is to be used in a stepping capacity, natural frequencies are computed to identify resonant conditions which could potentially cause excessive deflections. The finite element models show that the stage responds like a discrete lumped-mass system for the lower modes, and a continuous system with flexural characteristics for the higher modes.

Energy Technology Data Exchange (ETDEWEB)

The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.

International Nuclear Information System (INIS)

The present work gives preliminary results of analysis of drug mixtures (NEPHROSAL tea bag) and its water infusion. In a sample of dried drugs the elements K, Ca, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Pb were identified, whereas in their water infusion only Ca, Mn, Zn and Sr were found. The method applied was radionuclide X-ray fluorescence analysis using a radionuclide source "1"0"9Cd, a Si/Li semiconductor detector and a multichannel analyzer Canberra 8100. (author) 6 refs.; 3 figs.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with a Si/Li semiconductor detector and "2"3"8Pu exciting source was used in the study of Mn, Fe, Cu, Zn, and Pb content of solid emissions, raw and final materials of a brick factory. From the point of view of metal content, the working environment if the brick factory is safe for workers. (author) 2 refs.; 2 figs.; 1 tab.

Energy Technology Data Exchange (ETDEWEB)

An International Workshop on Metrology for X-ray and Neutron Optics has been held March 16-17, 2000, at the Advanced Photon Source, Argonne National Laboratory, near Chicago, Illinois (USA). The workshop gathered engineers and scientists from both the U.S. and around the world to evaluate metrology instrumentation and methods used to characterize surface figure and finish for long grazing incidence optics used in beamlines at synchrotrons radiation sources. This two-day workshop was motivated by the rapid evolution in the performance of x-ray and neutron sources along with requirements in optics figure and finish. More specifically, the performance of future light sources, such as free-electron laser (FEL)-based x-ray sources, is being pushed to new limits in term of both brilliance and coherence. As a consequence, ...

International Nuclear Information System (INIS)

The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios. The measured relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios were compared to the calculated ...

Energy Technology Data Exchange (ETDEWEB)

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emissions (2-20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3-8 ..mu..m. Extension of this coded imaging capability to higher energy x-rays (approx. 100 keV) and more penetrating charged particles (e.g. approx. 15 MeV protons) requires the fabrication of very thick (50-200 ..mu..m), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5-25 ..mu..m) for use as coded aperatures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures.

Science.gov (United States)

Kbeta-to-Kalpha X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti(x)Ni(1-x) (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi (109)Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured Kbeta-to-Kalpha X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the ...

British Library Electronic Table of Contents (United Kingdom)

The alloying effects on K to L shell vacancy transfer probabilities (?KL) in 3d transition metals have been carried out by X-ray fluorescence studies of various alloy compositions. K X-ray intensity ratios of Ti, Cr, Fe, Co, Ni, and Cu elements in the FexNi1?x, FexCr1?x, NixCr1?x, FexCryNi1?(x+y), TixNi1?x, TixCo1?x, and CoxCu1?x alloys have been measured following excitation by 22.69keV X-rays from a 10 mCi 109Cd radioactive point source and ?KL values for alloying elements have been determined from these ratios. The spectrum of characteristic K-X-ray photons from samples were detected with a high resolution Si(Li) detector coupled to a 4 K multichannel analyzer. The present investigation makes it possible to ...

Science.gov (United States)

radionuclide X-ray fluorescence analysis: the resolving power of the ... The radiation detectors used in radionuclide X-ray fluorescence ...

International Nuclear Information System (INIS)

Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.

Energy Technology Data Exchange (ETDEWEB)

Fe, Mn, Ni, V, Ti and Mo were determined in aerosols from manual arc welding. Samples of welding aerosols were trapped on a Synpor 4 filter. The amount of determined elements in aerosols was detected using the method of radionuclide X-ray fluorescence analysis. A /sup 241/Am annular source was used as the source of excitation radiation and radiation was processed using a Si(Li) spectrometer.

Energy Technology Data Exchange (ETDEWEB)

Fe{sub x}Zn{sub 1-x} alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K{beta}/K{alpha} x-ray intensity ratios of Zn and Fe in Fe{sub x}Zn{sub 1-x} thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5 keV photons emitted by a 50 mCi {sup 241}Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150 eV at 5.9 keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn-Fe alloys. It was found that the K-shell x-ray ...

Energy Technology Data Exchange (ETDEWEB)

A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the ...

CERN Document Server

We have monitored a Type II outburst of the Be/X-ray binary MXB 0656-072 in a series of pointed RXTE observations during October through December 2003. The source spectrum shows a cyclotron resonance scattering feature at 32.8 +/- 0.5 keV, corresponding to a magnetic field strength of (3.67 +/- 0.06) x 10^12 G and is stable through the outburst and over the pulsar spin phase. The pulsar, with an average pulse period of 160.4 +/- 0.4 s, shows a spin-up of 0.45 s over the duration of the outburst. From optical data, the source distance is estimated to be 3.9 +/- 0.1 kpc and this is used to estimate the X-ray luminosity and a theoretical prediction of the pulsar spin-up during the outburst.

CERN Document Server

We have developed a liquid jet injector system that can be used for hydrated sample delivery at X-ray Free Electron Laser (XFEL) sources and 3rd generation synchrotron sources. The injector is based on the Gas Dynamic Virtual Nozzle (GDVN), which generates a liquid jet with diameter ranging from 300 nm to 20 {\\mu}m without the clogging problems associated with conventional Rayleigh jets. An improved nozzle design is presented here. A differential pumping system protects the vacuum chamber and an in-vacuum microscope allows observation of the liquid jet for diagnostics while it is being exposed to the X-ray beam. A fiber optically coupled pump laser illuminating the jet is incorporated for pump-probe experiments. First results with this injector system have been obtained at the LCLS.

Science.gov (United States)

The principles of radionuclide excitation of X-ray fluorescence radiation and its application in

Energy Technology Data Exchange (ETDEWEB)

This paper presents calculations of the {sup 252}Cf-source-driven noise analysis measurements for subcritical highly enriched uranium metal cylinders using the Monte Carlo code MCNP-DSP. This code directly calculates the noise analysis data from the {sup 252}Cf- source-driven noise analysis method for both neutron and gamma ray detectors. Direct calculation of experimental observables by the Monte Carlo method allows for the benchmarking of the calculational model and the cross sections and for determining the bias in the calculation.

Energy Technology Data Exchange (ETDEWEB)

Exposure of teachers of physics to X-radiation emitted by instruments which are used for demonstrating rarefied gas discharges during physics lessons at secondary schools is discussed. The measurements performed provide an explicit evidence that an effective, annual exposure dose under the most unfavorable conditions does not exceed admissible levels according to Polish regulations pertaining to persons non-occupationally exposed to ionizing radiation. (author). 3 refs,1 fig.

Energy Technology Data Exchange (ETDEWEB)

Elements Ti, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb and Sr were determined by the method of radionuclide X-ray fluorescence analysis with semiconductor detection in samples of Taraxacum officinale from various localities of Bratislava. The dependence of their content on the source and the degree of the air pollution was found out.

International Nuclear Information System (INIS)

Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed. (author).

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with a Si/Li semiconductor detector and "2"3"8Pu exciting source was used in the determination of Cr, Fe, Ni, Cu, and Zn content in industrial wastewaters. Simultaneously, the effects of the wastewaters on activated sludge biocenose were evaluated. (author) 6 refs.; 1 fig.; 1 tab.

International Nuclear Information System (INIS)

The use of primary electron counting techniques as an alternative to the more usual parallel plate avalanche chamber that has been employed in soft x-ray scattering experiments is being investigated at the National Synchrotron Light Source. The theoretical aspects of primary electron counting and motivation behind building a primary electron counting detector are described, as well as characteristics and future improvements of the device constructed at the NSLS. The detector consists of a low electric field drift region and a low pressure multistep avalanche region which can be operated with two or three stages of electron multiplication. The device has worked well in extensive tests as a simple parallel plate avalanche chamber, providing energy resolutions of 58% and 43% at 277 and 500 eV, respectively. Operated as a primary electron counter, preliminary results show an energy resolution of 38% at 500 eV.

CERN Document Server

After two decades of direct dynamical simulation of large-scale structure in the universe, it is safe to say the subject is now mature. Still, there are parts of the problem that are less well developed than others. In general, the collisionless dynamics of the dark matter component is better understood than the collisional gas dynamics of the baryonic component. In situations where the gas dynamics is relatively simple, such as the Lyman-$\\alpha$ forest and the intracluster medium in X-ray clusters, our ability to reproduce observational data has evolved rapidly, and the interpretive and predictive power of such experiments should now be taken seriously. A comparison of twelve gas dynamic codes to the problem of forming a single X-ray cluster shows that numerical inaccuracies are modest (typically below ten percent), leaving missing physics as the main source for large systematic differences between theory and ...

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis for nondestructive determination of Fe, Zn, Pb, and Br in air samples collected on nitrocellulose membrane filter Synpor 4 is described. A /sup 238/Pu source for the excitation and a semiconductor Si/Li detector for the detection of characteristic and L-fluorescent radiation of the above elements were used. A correction method based upon the measurements of simple or multiple Compton scattering for compensation of varying mass per unit area values in sample deposits was theoretically proposed and experimentally tested. The results obtained both with and without the correction were compared and good agreement with those given by atomic absorption spectrometry was observed.

Energy Technology Data Exchange (ETDEWEB)

The LCLS, a Free-Electron Laser (FEL) designed for operation at a first harmonic energy of 300 eV ({lambda} {congruent} 40{Angstrom}) in the Self-Amplified Spontaneous Emission (SASE) regime, will utilize electron bunches compressed down to durations of <0.5ps, or lengths of <150 {mu}. It is natural to inquire whether coherent radiation of this (and longer) wavelength will constitute a significant component of the total coherent output of the FEL. In this paper a determination of a simple upper bound on the IR that can be generated by the compressed bunches is outlines. Under the assumed operating parameters of the LCLS undulator, it is shown that that IR component of the coherent output should be strongly dominated by the x-ray component.

Energy Technology Data Exchange (ETDEWEB)

Computed tomography (CT) has been incorporated in an industrial Diode-Array Digital Radiography (DADR) system. An input data size of 512 pixel points x 400 projections yielded a 400x400 output image matrix. Reconstruction algorithms used are the filtered backprojection (FBP) and the direct Fourier reconstruction (DFR). Various filters were used in the FBP reconstruction process and their effects on image quality were evaluated. A spatial resolution of 100 {mu}m was measured with a block of plates and a minimum detectable feature size in the range of 10-100 {mu}m was measured using thin wires. Industrial specimens imaged have included ceramic samples, ball bearings and integrated circuits. A number of engineering problems have been solved, such as adjustment of the X-ray source, centering of the rotator spindle in the view field and beam-hardening corrections. (orig.).

Science.gov (United States)

Polycrystalline powders of Na{sub 2x}Mn{sub 1-x}PS{sub 3} have been synthesized from layered MnPS{sub 3} material by successive ion-exchange intercalation of potassium and sodium ions. Their x-ray photoelectron spectroscopy (XPS) and x-ray excited Auger spectroscopy spectra have been measured at room temperature using Mg K{alpha} (1253.6 eV) x-ray source. In particular, the Mn, P, and S 2p and Na 1s and 2p core-level regions and the Na Auger KL{sub 23}L{sub 23} transition have been investigated. All the analyzed XPS core-level spectra display a single-peak structure, suggesting the absence of nonequivalent atoms of Na, Mn, P, and S. The manganese XPS spectrum shows, as observed in MnPS{sub 3} and in its cesium and potassium intercalation compounds, typical shake-up satellites, suggesting that the Mn-S bond is yet mainly ionic in nature. The comparison with the XPS spectra relative to MnPS{sub 3} and its ...

Energy Technology Data Exchange (ETDEWEB)

Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase contrast too narrow for detection with CR. In addition to phase ...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis is a method, which has many advantages for analysing various historic artefacts, as it is relatively cheap, sensitive and non-destructive, and it allows measurements in-situ. However, this analysis has also certain limitations especially concerning sensitivity to chemical elements only, irrespective of the compounds or chemical forms in which these elements have been bonded. In addition, light elements emitting very soft X-rays cannot be measured, and in order to detect a wide range of elements, it is necessary to carry out repeated measurements with different radiation sources. Despite these limitations, valuable information can be obtained about the composition of historic materials and data about the origin and age of these artefacts can be derived. Analyses of wall paintings, ancient metal sculptures or other objects of art provide the basis for historic considerations documented ...

Energy Technology Data Exchange (ETDEWEB)

One aspect of the research program SFB 570 'Distortion engineering' is the in situ X-Ray diffraction analysis of phases and residual stresses during complete heat treatment cycles. These investigations result in experimental evidence available for the extensive computations. The optimisation of the instrumentation will be reported. A surface decarburisation of samples made from the ball bearing steel 100Cr6 could be avoided for a temperature range from 800 to 900 C and a holding time of one hour by a combination of evacuate the furnace and using a certain nitrogen flow as protective gas. At lower temperatures small amounts of ferrite caused by an increased diffusion rate of carbon lead again to a surface decarburisation up to a depth of 2 {mu}m. It was proved that with an evacuation of the X-Ray beam path at constant power of the X-Ray source the intensity of diffraction lines could be ...

Energy Technology Data Exchange (ETDEWEB)

The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to 1/{radical}{beta}. Thus the electron beam is very ...

International Nuclear Information System (INIS)

An X-ray fluorometric train was set up for analyzing gravitational fallout, and tested on standard reference samples of fly ashes from conventional power plants. Analysis of thin layers proved inappropriate, and therefore pelletization of the samples, either alone or together with the X-ray MIX binder, was applied. Sample grinding in an agate mortar was found sufficient to suppress the particle size effect. The optimum pressure was 20 MPa. The optimum geometry was sought for "1"0"9Cd source, and limits of detection of 2.78-0.47 #mu#g were achieved for Cr-Zr elements. Tominaga's method was employed for matrix effect correction. Ti, Fe, Cu, Zn, As, Rb, Sr, Zr and Pb were determined in the SRM's; the relative errors ranged from units per cent (for Zn, Rb, Sr and Zr present in concentrations about 100 ppm and for Fe in concentrations of units per cent) up to 45% (for Ti present in a concentration of 0.67%). The method developed ...

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

CERN Document Server

We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%).As expected, the distribution of intrinsic absorbing column densities is markedly different between AGN with or without broad optical emission lines. We find within our sample four Type-2 QSOs candidates (L_X > 10^44 erg/s, N_H > 10^22 cm^-2), with a spectral energy distribution well reproduced by a composite Seyfert-2 spectrum, that demonstrates the strength of the wide field XMM/COSMOS survey to detect these rare and underrepresented sources.

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) based on the final kilometer of the Stanford Linear Accelerator. One of the most critical diagnostic devices is the bunch length monitor (BLM), which is to be installed right after each compressor utilizing coherent radiation from the last bending magnet. We describe the components and the optical layout of such a BLM. Based on the setup geometry, we discuss some issues about the coherent radiation signal.

International Nuclear Information System (INIS)

The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, whereas the other decelerates, corresponding to a confined flow.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis and fast neutron activation analysis were used for the determination of chromium. The excitation source for X-ray fluorescence analysis was a ring-shaped "2"4"1Am source with an activity of 18.5x10"9 Bq. SYNPOR filters of 35 mm in diameter were used for the measurement. The 5.414 keV Cr peak was measured with a Si(Li) detector. The sensitivity was 0.05 mg for a period of measurement of 1000 s. A neutron generator with an emission of 10"9 s"-"1 was used as the source of fast neutrons. "5"2V and "5"3V, the products of nuclear reaction with Cr, were measured gamma spectrometrically with a Ge(Li) detector. The sensitivity for Cr is 0.015 mg, in the presence of Mn which causes interference the sensitivity is a mere 0.075 mg. The mentioned methods were used to determine total Cr and Cr(VI) in welding aerosols. It was found that the most toxic form, ...

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti{sub x}Ni{sub 1-x} (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi {sup 109}Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured K{beta}-to-K{alpha} X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other ...

Science.gov (United States)

The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ...

International Nuclear Information System (INIS)

The purpose of this work is to present a comprehensive, instructive analysis of the basis of radionuclide XRFA, to describe methods of sample preparation for environmental analysis and to make the reader more familiar with the procedures, methods and instrumentation of radionuclide XRFA used in this field. This book discusses the use of radionuclide XRFA for solving analytical problems of the environment and information is presented concerning the current state of research and use of radionuclide XRFA in this significant area. The present volume will serve as a basic source of data and also as a laboratory handbook. refs.; figs.; tabs.

International Nuclear Information System (INIS)

Radionuclide x-ray fluorescence analysis was used for the determination of Fe, Zn, Br and Rb levels in whole blood from dilated cardiomyopathy patients and from a control group. The XRF-system consisted of a radionuclide source "1"0"9Cd, a semiconductor Si/Li detector connected to a multichannel analyzer. Fe content in blood of patients was significantly lower than that of the control. Zn content showed no deviation from normal range. Values for Br and Rb in patients highly exceed the range reported for them. (author) 4 tabs.; 9 refs.

International Nuclear Information System (INIS)

We consider the spin-up of the white dwarf in non-magnetic cataclysmic variables (CVs) during secular evolution. If this is unresisted, CVs are quenched as boundary-layer emitters once the binary period has decreased by #approx# 1 hr. Angular momentum loss in nova explosions may, however, prevent the star reaching breakup. If the explosions remove (1 + #epsilon#) x the mass accreted between outbursts, values 0.5 < #approx# #epsilon# < #approx# 1 allow CVs to be modest boundary-layer emitters for most of their lifetimes. Spectral effects will limit their detection as soft X-ray sources. (author).

International Nuclear Information System (INIS)

The K sub(#alpha#)/K sub(#beta#) intensity ratio of Mn KX-rays scattered by metallic samples changed remarkably with the geometry between the sample and the "5"5Fe source-Si(Li) detector system. On the contrary, this intensity ratio changed little in the cases of non-metallic scatterer samples such as lucite or mylar. This difference is interpreted as due to the occurrence of strong or weak interference in the coherent scattering photons. (author).

Energy Technology Data Exchange (ETDEWEB)

The use of the method is described on powder samples before and after sintering with a La content of up to 1%. For excitation of the K series of La a /sup 241/Am source with an activity of 1.11 GBq was used. The obtained results showed that the method is sufficiently accurate (error 7%) at a short period of measurement (100 s). It gives satisfactory results even in the comparison of the experimental relative count rate and the theoretically calculated value despite the fact that the analytical signal comes from the sample surface.

Science.gov (United States)

The properties and kinetics of x-ray stars in globular clusters are described. Locations, configurations, star evolution, massive close binary systems, various mechanisms, and the x-ray burster properties are included. (JFP)

International Nuclear Information System (INIS)

ASTROSAT, India's first dedicated astronomy satellite is slated for launch in 2007. The primary science objective of ASTROSAT is to explore the Universe using broad-band instruments covering optical, UV, soft X-ray and hard X-ray studies

Energy Technology Data Exchange (ETDEWEB)

The X-ray photoacoustic spectra of copper and brass (64.7 wt.% Cu and 35.3 wt.% Zn) have been measured at XANES (X-ray absorption near-edge structure) regions using synchrotron radiation. These spectra were compared with optical density of X-ray spectra. It is shown that the information derived from XANES is also included in the X-ray photoacoustic spectrum which reflects the heat production processes in copper and brass. However, the results showed that the increases and changes of the photoacoustic signal were different from those of the X-ray absorption coefficient at XANES regions. (author).

Science.gov (United States)

Mar 1, 2011 ... Radionuclide X-ray fluorescence analysis. 2: Detection of the X-ray fluorescence radiation excited by radionuclide radiation ...

Science.gov (United States)

Aug 1, 1972 ... The principles of radionuclide excitation of X-ray fluorescence radiation and its application in analytic chemistry are discussed.

International Nuclear Information System (INIS)

The present document represents an attempt to summarize the most important features of the different forms of ED-XFR as applied to the analysis of airborne particulate matter. It is intended to serve as a set of guidelines for use by participants in the IAEA's own programmes, and other scientists, who are not yet fully experienced in the application of ED-XRF to airborne particulate samples, and who wish either to make a start on using this technique or to improve their existing procedures. The methodologies for sampling described in this document are of rather general applicability. Emphasis is also placed on the sources of errors affecting the sampling of airborne particulate matter. The analytical part of the document describes the different forms of ED-XRF and their potential applications. Spectrum evaluation, a key step in X-ray spectrometry, is covered in depth, including discussion on several calibration and peak fitting techniques and ...

CERN Document Server

Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and inexpensive ultra-high resolution imaging system on 5C1 beamline was successfully implemented. The authors were able to acquire ...

Science.gov (United States)

Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 {mu}s exposure and spatial resolution of 10 {mu}m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were revealed. These include processes such as the initiation of ...

Energy Technology Data Exchange (ETDEWEB)

K{beta}-to-K{alpha} X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV {gamma}-rays from a 200 mCi {sup 241}Am point-source. The K{beta}-to-K{alpha} intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K{beta}-to-K{alpha} intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi{sub 2} and CuSi{sub 2}.

International Nuclear Information System (INIS)

Radioactive particles as well as x irradiation from an external source has been used in the treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. In order to clarify effects of ionizing irradiation on synovial cells, radioactive gold ("1"9"8Au) and yttrium ("9"0Y) were added to fibroblast cultures derived from human synovial membranes. Other cultures were irradiated by a Picker x-ray machine. Fibroblast growth and hyaluronic acid production were measured. Radioactive gold and yttrium particles induced a significant increase of hyaluronic acid synthesis rate (pg/cell/day) and inhibited fibroblast growth. Fibroblasts continued to overproduce hyaluronic acid and to show growth inhibition 3 weeks after irradiation with radioactive gold. Hydrocortisone inhibited hyaluronic acid overproduction induced by radioactive gold. Overproduction of hyaluronic acid induced by the x-ray machine was inhibited by ...

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

International Nuclear Information System (INIS)

The effect of resonance, observed in X-ray waveguide layered structures in a characteristic way influences the scattering properties of the films. It is well known that the resonant region in the reflectivity shows a series of minima, usually very deep and extremely narrow. The positions and depths of the minima depend only on X-ray waveguide and quasi X-ray waveguide film structural properties, on the X-ray wavelength and on the incident beam divergence. In the present work we propose and discuss the application of the X-ray waveguide and quasi X-ray waveguide film structures as a tools to experimental evaluation of some quantities related to X-ray reflectometric and diffractometric measurements, like the beam divergence, wavelength, or angular distance. Examples of application of X-ray waveguide as an excellent tool ...

Energy Technology Data Exchange (ETDEWEB)

The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of {gamma}-ray binaries.

International Nuclear Information System (INIS)

The opportunity of use self-maintained plasma-beam discharge in an extended pulsing plasma diode of low pressure for making powerful sources of the soft X-rays is investigated. Conditions of formation of the self-maintained plasma-beam discharge are determined. The mode of making of dense high-temperature plasma on the basis of stannum ions in the discharge is shown. The stannum ions are used as a working element of a radiation sources at pulsing power of electron beam P?10...100 MW. Results of the examination on formation of the dense (np?1016 cm3), small sizes (le?100 eV in conditions of working material evaporation from the anode are given. The total contribution of energy to the discharge has made W < 20 J.

Energy Technology Data Exchange (ETDEWEB)

With the exception of the 1945 Hiroshima and Nagasaki nuclear weapon explosions and the 1986 Tchernobyl reactor accident, most of the radiation accidents concerns the medical and the traditional industrial sectors. The seriousness of the accident is directly function of the absorbed dose. The paper, first, gives the definition of a radiologic accident with its specific criteria and pathological manifestations. Then, some famous historical accidents are reviewed from the discovery of X-rays to recent acute irradiations due to the careless manipulation of radiation sources. From this analysis, three main causes are put forward: the dysfunction of nuclear medicine apparatuses, the victims` lack of training and knowledge of the risks, and the non-identification or the loss of radiation sources. (J.S.). 1 photo.

Energy Technology Data Exchange (ETDEWEB)

The energy dispersive beamline X6A at the National Synchrotron Light Source employs a curved crystal monochromator (polychromator) which focuses a range ([similar to]1 keV) of x-ray energies into a narrow (100--120 [mu]m) line image. Although this beamline was constructed primarily for time-dependent EXAFS experiments, we have begun to explore the use of this instrument for energy dispersive diffraction experiments with different types of sample including macromolecular crystals. The tunability ([ital E]=6.5 to 21 keV) and flexibility ([Delta][ital E]=100--1000 eV) of the instrument makes the beamline ideal as a test bed for the application of polychromatic single-crystal diffraction techniques to different chemical or biological materials.

Energy Technology Data Exchange (ETDEWEB)

A novel scheme is proposed to drive a low-power subcritical fuel assembly by means of a long Cylindrical Radially-convergent Inertial Electrostatic Confinement (CRIEC) used as a neutron source. The concept is inherently safe in the sense that the fuel assembly remains subcritical at all times. Previous work has been done for the possible implementation of CRIEC as a subcritical assembly driver for power reactors. However, it has been found that the present technology and stage of development of IEC-based neutron sources can not meet the neutron flux requirements to drive a system as big as a power reactor. Nevertheless, smaller systems, such as research and training reactors, could be successfully driven with levels of neutron flux that seem more reasonable to be achieved in the near future by IEC devices. The need for custom-made expensive nuclear fission fuel, as in the case of the TRIGA reactors, is eliminated, and the ...

Energy Technology Data Exchange (ETDEWEB)

Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with {approximately}99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the ...

International Nuclear Information System (INIS)

Brief item.

International Nuclear Information System (INIS)

Global angular momentum balance suggests that the neutron stars in Be/X-ray binaries are not spinning in equilibrium. This requires an X-ray lifetime ''approx <'' 10"5 yr, and suggests that there are many 'dead' Be/X-ray binaries in the Galaxy. Some of these may be turned up as millisecond radio pulsars with Be star companions. (author).

International Nuclear Information System (INIS)

Published in summary form only.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Examples are given of the applicability and importance of radionuclide fluorescence analysis as a

International Nuclear Information System (INIS)

X-ray imaging is a very useful plasma diagnostic method. A theoretical analysis of the x-ray phase imaging in the method based on Fresnel diffraction is given. The authors show it is a linear band pass filter, a property suit for Rayleigh-Taylor (R-T) instability measurement. The evaluation permits the possibility of R-T instability measurement in x-ray phase imaging

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

... such as renal flow scan or a formal kidney X-ray, called an intravenous pyelogram ( IVP ), may help ...

International Nuclear Information System (INIS)

Published in summary form only.

International Nuclear Information System (INIS)

I present an exact calculation of free-electron-laser (FEL) eigenmodes (fundamental as well as higher order modes) in the exponential-gain regime. These eigenmodes specify transverse profiles and exponential growth rates of the laser field, and they are self-consistent solutions of the coupled Maxwell-Vlasov equations describing the FEL interaction taking into account the effects due to energy spread, emittance and betatron oscillations of the electron beam, and diffraction and guiding of the laser field. The unperturbed electron distribution is assumed to be of Gaussian shape in four dimensional transverse phase space and in the energy variable, but uniform in longitudinal coordinate. The focusing of the electron beam is assumed to be matched to the natural wiggler focusing in both transverse planes. With these assumptions the eigenvalue problem can be reduced to a numerically manageable integral equation and solved exactly with a kernel iteration method. An approximate, but more ...

International Nuclear Information System (INIS)

The author's achievements in the title field are summarized and discussed. The following topics are dealt with: (i) principles of radionuclide X-ray fluorescence analysis; (ii) mathematical methods in X-ray fluorescence analysis; (iii) Ross differential filters; (iv) application of radionuclide X-ray fluorescence analysis in the coal industry (with emphasis on the determination of the ash content, sulfur content, and arsenic content of coal); and (v) evaluation of the X-ray fluorescence analyzer from the radiological safety point of view. (P.A.).

CERN Document Server

We construct a sample of low-redshift Ly-alpha emission-line selected sources from GALEX grism spectroscopy of nine deep fields to study the role of Ly-alpha emission in galaxy populations with cosmic time. Our final sample consists of 122 (142) sources selected in the redshift interval z=0.195-0.44 (z=0.65-1.25) from the FUV (NUV) channel. We classify the Ly-alpha sources as AGNs if high-ionization emission lines are present in their UV spectra and as galaxies otherwise. These classifications are broadly supported by comparisons with X-ray and optical spectroscopic observations. We classify additional sources as AGNs using line widths for our Ly-alpha emitter (LAE) analysis. Defining the GALEX LAE sample in the same way as high-redshift LAE samples, we show that LAEs constitute only about 5% of NUV-continuum selected galaxies at z~0.3. We also show that they are less common at ...

Energy Technology Data Exchange (ETDEWEB)

The /sup 252/Cf-source-driven noise analysis method determines the subcriticality of a system containing fissionable material from the ratio of cross power spectral densities between the detectors that detect particles from the fission process and between these detectors and an ionization chamber containing a spontaneously fissioning neutron source which provides neutrons to induce fission in the system. This method has two advantages: (1) a calibration is not required and thus subcriticality can be determined from measurements only on the subcritical system of interest, and (2) the subcriticality is independent of the type of detector or its efficiency. These properties of this technique are illustrated by measurements.

Energy Technology Data Exchange (ETDEWEB)

This paper describes recent measurements of the subcritical neutron multiplication factor using the /sup 252/Cf source-driven neutron noise analysis method. This work was supported by a program of collaboration between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan related to the development of fast breeder technology. The experiment reported consists of a configuration of two interacting tanks of uranyl nitrate aqueous solution with different uranium concentrations in each tank. The /sup 252/Cf-source-driven neutron noise analysis method obtains the subcriticality from the signals of three detectors: the first, a parallel plate ionization chamber with /sup 252/Cf electroplated on one of its plates that is located in or near the system containing the fissile material, and produces an electrical pulse for every spontaneous fission that occurs and thereby serves as a timed ...

International Nuclear Information System (INIS)

The most important commercialized methods of attenuation correction in SPECT are based on attenuation coefficient map from a transmission imaging method. The transmission imaging system can be the linear source of radioelement or a X-ray CT system. The image of transmission imaging system is not useful unless to replacement of the attenuation coefficient or CT number with the attenuation coefficient in SPECT energy. In this paper we essay to evaluate the validity and estimate the error of the most used method of this transformation. The final result shows that the methods which use a linear or multi-linear curve accept a error in their estimation. The value of mA is not important but the patient thickness is very important and it can introduce a error more than 10 percent in the final result.

Energy Technology Data Exchange (ETDEWEB)

New values of the factors required to convert the reading of a radiation dosemeter calibrated in terms of air kerma (or exposure) into absorbed dose to water for medium-energy x-radiation were given in a code of practice published by the International Atomic Energy Agency in 1987. These are not considered to possess sufficient support from other sources. It is therefore recommended that the F-factors given or codes of practice should continue to be used. Values of backscatter factors for low-energy x-radiation (below 140 kV) in Supplement 17 of the British Journal of Radiology appear to be inaccurate. New values based on Monte Carlo calculations, and supported by new experimental data, are given for use in radiotherapy. (author).

CERN Document Server

Relativistic strongly magnetized winds outflowing from fast-rotating compact objects like millisecond pulsars with surface magnetic fields of $\\sim 10^{15}-10^{16}$ G are plausible sources of cosmological $\\gamma$-ray bursts. In such winds, there are at least three regions where extremely powerful X-ray and $\\gamma$-ray emission may be generated. The first radiating region is the wind photosphere that is at a distance of $\\sim 10^9$ cm from the compact object. The second radiating region is at a distance of $\\sim 10^{13}-10^{14}$ cm. In this region, the striped component of the wind field is transformed into large-amplitude electromagnetic waves. The third radiating region is at a distance of $\\sim 10^{16}-10^{17}$ cm, where deceleration of the wind due to its interaction with an ambient medium becomes important. Radiation from all these regions is considered.

International Nuclear Information System (INIS)

Silicon layered structures containing porous silicon modified with various thermal treatments and epitaxial layers deposited on porous layers were studied with a number of complementary X-ray diffraction methods using synchrotron source. The methods of characterization included recording of rocking curves for reflections with various asymmetry as well as projection, section and micro-Laue topography. It was found that oxidizing and sintering of porous silicon seriously modified the strains in the porous layer and in some cases even inverting the sense of strain with respect to that in initially formed porous layer. Consequently the deposited epitaxial layer usually was not laterally coherent with the substrate. Some of investigated layers were not stable in time and after few months period exhibited significant lost of coherence of porous skeleton. (author)

International Nuclear Information System (INIS)

Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.

Science.gov (United States)

X-ray diffraction offers a unique combination of advantages for kinetic study which include the non-destructive nature of the measurement, the use of bulk crystals, and the convenience of the experimental arrangements. These attributes and the availability of position-sensitive detectors and high-flux synchrotron radiation sources make this technique most useful for in situ, dynamical investigations. When using diffraction techniques to determine a diffusion coefficient, the principle of analysis entails a scattering theory and a kinetic model. The former allows the kinetic parameter(s) to be extracted from measured intensity, while the latter relates the kinetic parameter(s) to the diffusion coefficient(s). Three examples are demonstrated: (1) Palladium Silicide (Pd{sub 2}Si) Layer Growth on Silicon, (2) Decomposition of an Ni-12.5at%Si Superalloy, and (3) Short-range Ordering in Cu-Au Solid Solutions.

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

International Nuclear Information System (INIS)

The sampling is described for radionuclide X-ray fluorescence analysis. Aerosols are captured with various filter materials whose properties are summed up in the table. Fine dispersed solid and liquid particles and gaseous admixtures may be captured by bubbling air through a suitable absorption solution. The concentration of small amounts of impurities from large volumes of air is done by adsorbing impurities on surfactants, e.g., activated charcoal, silica gel, etc. Aerosols may be captured using an electrostatic precipitator and aerosol fractions may be separated with a cascade impactor. Water sampling differs by the water source, i.e., ground water, surface water, rain or waste water. Soil samples are taken by probes. (ES).

International Nuclear Information System (INIS)

Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a ...

DEFF Research Database (Denmark)

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted.

CERN Document Server

The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C 31. We use the parameters derived from the modelling presented by \\cite{lb02a,lb02b} as input parameters for the simulation of the evolution of the source, thus assuming that they have not varied over the lifetime of the source. We simulate about 10 % of the total lifetime of the jets in 3C 31. Realistic density and pressure gradients for the atmosphere are used. The simulation includes an equation of state for a two-component relativistic gas that allows a separate treatment of leptonic and baryonic matter. We compare our results with the modelling of the observational data of the source. Our results show that the bow shock evolves self-similarly at a quasi-constant speed, with slight ...

International Nuclear Information System (INIS)

The effect of anode length and operating gas pressure on the x-ray emission from a nitrogen-filling modified plasma focus device has been investigated. The time-resolved investigation of x ray was carried out by using a five-channel photodiode x-ray spectrometer. The maximum x-ray yield is seen to increase with the increase in the anode length from 110 to 125 mm. Further increase in the anode length to 130 mm causes the x-ray yields to decrease. The highest x-ray yield of 4.5 J into 4#pi# sr was found for 125 mm anode length, which is 0.2% of the input energy. The average x-ray photon energy was estimated by using half-value thickness method and found to be 8.4 keV. The electron temperature of the plasma was estimated to be around 3 keV by x-ray intensity ratio method. The space-resolved ...

Energy Technology Data Exchange (ETDEWEB)

The ability of the /sup 252/Cf-source-driven neutron noise analysis method to measure subcriticality has been demonstrated in a variety of experimental configurations of fissile materials. Calculations for an approximately 4-m-dia configuration of light water reactor (LWR) fuel elements indicated the feasibility of measuring the subcriticality of large, loosely coupled arrays of LWR fuel elements by this same method. These analysis suggested application to the initial loading of both pressurized and boiling water reactors, zero-power testing of reactors (such as shutdown margin measurements after initial loading), light water reactor refueling, and safe storage of LWR spent fuel. In the fuel storage application, direct measurement of subcriticality in the actual fuel storage facilities provides the parameter which is directly related to criticality safety.

Science.gov (United States)

... Accession Number : ADA535309. Title : X-Ray Phase Imaging for Breast Cancer Detection. Descriptive Note : Annual rept. 1 Sep 2009-31 Aug 2010 ...

UK PubMed Central (United Kingdom)

Microplanar beam radiation therapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid.

International Nuclear Information System (INIS)

Exact anatomic knowledge about the location of the gonads and the application of corresponding measures of radiation protection are the preconditions for an efficient reduction of the danger of a possible genetic damage as a result of radiation exposition during X-ray examination of the hip joint of newborns. (VJ).

International Nuclear Information System (INIS)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K_#alpha# X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K_#alpha# X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the ...

UK PubMed Central (United Kingdom)

An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring...Full Text Available

UK PubMed Central (United Kingdom)

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available

International Nuclear Information System (INIS)

Experimental, relative intensities for the components of L X-ray were collected from literature, and atomic-number dependency of L#beta#/L#alpha# has been found. (author).

Science.gov (United States)

SN 1987A: Soft X-Ray Intensity Ratio. 2002-12 to 2000-12. 2005-7 to 2002-12. Contours: 2002-12. (0.5 2 keV). (0.5 2 keV). Contours: 2005-7 ...

International Nuclear Information System (INIS)

Bi-U mixed oxides were synthesized by two methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The samples were tested for the catalytic oxidation of carbon monoxide by oxygen. A stepwise redox mechanism consistent with the kinetic results is proposed. (orig.).

UK PubMed Central (United Kingdom)

Previous studies have shown that iterative in-line x-ray phase retrieval algorithms may have higher precision than direct retrieval algorithms. This communication compares three iterative phase...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This research focuses on the development and application of high order statistical analyses applied to measurements performed with subcritical fissile systems driven by an introduced neutron source. The signatures presented are derived from counting statistics of the introduced source and radiation detectors that observe the response of the fissile system. It is demonstrated that successively higher order counting statistics possess progressively higher sensitivity to reactivity. Consequently, these signatures are more sensitive to changes in the composition, fissile mass, and configuration of the fissile assembly. Furthermore, it is shown that these techniques are capable of distinguishing the response of the fissile system to the introduced source from its response to any internal or inherent sources. This ability combined with the enhanced sensitivity of higher order signatures ...

Energy Technology Data Exchange (ETDEWEB)

Abstract not provided

Energy Technology Data Exchange (ETDEWEB)

The preparation by sputtering of artificial metallic superlattices is described, as are the results of x-ray structural determinations. Tunneling and resistivity measurements on these materials are reported.

International Nuclear Information System (INIS)

Slovak May 1981. p. 30. Czechoslovakia Sandrik, R. Kliment, V.

International Nuclear Information System (INIS)

Czech Apr 1986. p. 51. Czechoslovakia Cechak, T. Kluson, J. Ceske

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

The ELXS concept is a novel, portable, micro-instrument targeted for the detection of mineralogic

International Nuclear Information System (INIS)

High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.

Energy Technology Data Exchange (ETDEWEB)

Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {gamma}1} X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L{sub {gamma}1}/L{sub {beta}1} X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).

Energy Technology Data Exchange (ETDEWEB)

This case report evaluates X-ray findings in patients with miliary accumulation of mercury observed after parenteral application of metallic mercury in a suizide attempt. There are certain discrepancies between clinical symptoms and the X-ray findings. A clear demonstration of mercury in coronary blood vessels is possible by fluoroscopy.

International Nuclear Information System (INIS)

Applications of X-ray fluorescence analysis in coal mining and geology are briefly described based on results published in Czechoslovakia as well as abroad over the past 3 years. Particular attention is paid to the rapid determination of the ash content of coal using portable radionuclide X-ray fluorescence analyzers that are being developed in Czechoslovakia. (author).

International Nuclear Information System (INIS)

At the RIKEN-RAL Muon Facility, ?- to ? sticking K? X-rays were observed for the first time taking advantage of the pulsed beam structure. The precision of the present measurements was insufficient to distinguish between theoretical models, however the observed K?/K? X-ray intensity ratio tends to be smaller than most of these theoretical predictions.

Energy Technology Data Exchange (ETDEWEB)

In this article, the author presents the main technological solutions, available or in development, on X-ray detectors in order to obtain a digital image in biomedical radiography or in industrial radiography: linear x-ray detectors and bidimensional x-ray detectors (memory radioluminescent screens, matrix plan detectors).

Energy Technology Data Exchange (ETDEWEB)

The Synchrotron Resource of the Howard Hughes Medical Institute will be dedicated to structural analyses of biological macromolecules, primarily through crystallography. This facility is under construction at the X4 port of the National Synchrotron Light Source at Brookhaven National Laboratory, and it will comprise three beamlines. The first line to be built has been devised to apply the multiwavelength anomalous diffraction method which provides direct estimates for the phases of reflections. The second line will be devoted to rapid and essentially routine diffraction measurements, mainly through the rotation method. These two experimental stations are contained within refrigerated radiation enclosures that will maintain clean environments, narrowly defined constant temperatures, and protection against biohazard at biosafety level BL-2. At the same time as the second line will be developed, the swath center is planned to first serve as a monitor of the white ...

International Nuclear Information System (INIS)

Ozone production by synchrotron radiation as a function of power density in air was investigated using a white beam at the BNL National Synchrotron Light Source (NSLS) x-ray ring. Power densities were calculated from the energy spectrum at 2.52 GeV. Ozone concentrations in small beam pipes were measured for power densities between I = 10"1"2 and 10"1"5 eV . cm"-"3 . sec"-"1. The measured ozone half-life was 37 +- 2 min. The measured G-value was 2.69 +- 0.14 mol/100 eV and the ozone destruction factor k was less than 7 x 10"-"1"9 cm"3 . eV"-"1. The random uncertainties stated are approximately one standard error. The large departure of the values for G and k from previous values suggest that some undiscovered systematic error may exist in the experiment. Ozone concentration in excess of the 0.1 ppM ACGIH TLV can be generated in the experimental hutches but can readily be controlled. Industrial hygiene aspects of operation and possible control ...

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test the digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. Finally, logging of meaningful data into files has been added.

Energy Technology Data Exchange (ETDEWEB)

The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcriticality of an assembly of fissile material from cross-power spectral densities (CPSDs) was developed to avoid some difficulties inherent in other measurement methods. This method requires measurement of frequency-dependent CPSD between a pair of detectors in or near the fissile assembly and CPSDs between these detectors and a source of correlated neutron noise from an ionization chamber containing /sup 252/Cf, also in or near the fissile assembly. Also, the auto-power spectral density of the source is required. The ratio of spectral densities is then formed and is related to the subcriticality. To date various measurements have been performed which demonstrate the usefulness of the method including measurements with single uranium metal cylinders. The experiments described here, which used coupled uranium (93.15 wt % /sup 235/U) metal ...

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr_0_._2_6Fe_0_._7_4, Cr_0_._8_0Co_0_._2_0 and Ti_0_._8_0Cr_0_._2_0 alloys have been measured following excitation by 59.54 keV #gamma#-rays from a 7400 MBq (200 mCi) "2"4"1Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys with respect to the pure metals, except for Cr in ...

Energy Technology Data Exchange (ETDEWEB)

The design of the first structural wall (FSW) in an inertial confinement fusion (ICF) reactor requires some knowledge of the expected wall loading produced by x-ray and neutron deposition; specifically in the High Yield Lithium Injection Fusion Energy (HYLIFE) reactor, wall loading results from two sources -- gas shock and liquid impact. Gas shock is derived from x-ray deposition in the thin layers of exposed blanket material, producing ionized vapor, which will generate gas shock on the FSW. Liquid impact, on the other hand, results from the acceleration of liquid blanket material by two possible forces -- the drag from vapor expansion through the blanket material and the neutron-induced isochoric disassembly process. Both impacts, however, are coupled by the interaction of hot gas expanding through the liquid blanket. This paper discusses scaling methods for estimating pressure and impulse on the HYLIFE FSW from these ...

International Nuclear Information System (INIS)

K#beta#-to-K#alpha# x-ray intensity ratios of Fe and Ni in pure metals and in Fe_xNi_1_-_x alloys (x=0.20, 0.50, 0.58) exhibiting similar crystalline structure have been measured following excitation by 59.54 keV #gamma# rays from a 200 mCi "2"4"1Am point source to understand why the properties of the Fe_xNi_1_-_x (x=0.2) alloy are distinct from other alloy compositions. The valence electronic structure of Fe and Ni in the samples has been evaluated by comparing the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations. Significant changes in the 3d electron population (with respect to the pure metal) are observed for Fe and Ni for certain alloy compositions. These changes can be explained by assuming rearrangement of electrons between 3d and (4s,4p) band states of the individual metal atoms. It has been found that the valence electronic structure of the Fe_0_._2Ni_0_._8 alloy is totally ...

International Nuclear Information System (INIS)

Lifetime of minority charae carriers in the Si and Ge p-n unctions has been measured by pulse method of conductivity modulation of base. Its dependence on the X-ray radiation dose has been investigated. Dependence of current transmission coefficients on the dose has been measured and their sharp decrease at low doses and the following saturation at high doses have been observed. Linear dependence of lifetime on X-ray radiation dose has been obtained. Resulting from the comparison of regularities of the change of lifetime due to current characteristics, it has been shown that X-ray radiation leads to the formation of the surface defects, influencing the change of current characteristics as well as to stationary structural defects, causing the decrease of lifetime of the charge carriers with the increase of X-ray radiation dose.

Energy Technology Data Exchange (ETDEWEB)

We propose and analyze a novel regenerative amplifier free electron laser (FEL) to produce fully coherent x-ray pulses. The method makes use of narrow-bandwidth Bragg crystals to form an x-ray feedback loop around a relatively short undulator. Self-amplified spontaneous emission (SASE) from the leading electron bunch in a bunch train is spectrally filtered by the Bragg reflectors and is brought back to the beginning of the undulator to interact repeatedly with subsequent bunches in the bunch train. The FEL interaction with these short bunches not only amplifies the radiation intensity but also broadens its spectrum, allowing for effective transmission of the x-rays outside the crystal bandwidth. The spectral brightness of these x-ray pulses is about two to three orders of magnitude higher than that from a single-pass SASE FEL.

International Nuclear Information System (INIS)

We report the detection of X-ray pulsations with a period of ?315.87 ms from the 2009 XMM-Newton observation for the radio-quiet ?-ray pulsar, LAT PSR J0007+7303, centered in the supernova remnant CTA 1. The detected pulsed period is consistent with the ?-ray periodicity at the same epoch found with the Fermi Gamma-ray Space Telescope. The broader sinusoidal structure in the folded light curve of the X-ray emission is dissimilar to that of the ?-ray emission, and the phase of the peak is about 0.5 shifting from the peak in the ?-ray bands, indicating that the main component of the X-rays originates from different sites of the pulsar. We conclude that the main component of the X-ray pulsation is contributed by the thermal emission from the neutron star. Although with a significantly different characteristic age, PSR J0007+7303 is similar to Geminga in emission properties of X-rays ...

CERN Document Server

Jet-driven shocks are responsible for an important fraction of the emission of the narrow-line regions (NLRs) in many classes of AGN. However, this cannot explain all observations. It is clear that the remaining sources are photoionised by the active nucleus. The 2-d hydrodynamic models from the RSAA group support an evolutionary scenario whereby the shock-excited NLRs are initially jet-driven but later, ionizing photons from the central engine replace shocks as the main excitation mechanism and shock induced star formation may also become important. In their photoionized phase, dusty and radiation-pressure dominated evolution produces a self-regulated NLR spectrum. This model aso explains the coronal emission lines and fast (3000 km s$^{-1}$) outflows seen in some Seyferts.

International Nuclear Information System (INIS)

For a given linac design, the dosimetric characteristics of a photon beam are determined uniquely by the energy and radial distributions of the electron beam striking the x-ray target. However, in the usual commissioning of a beam from measured data, a large number of variables can be independently tuned, making it difficult to derive a unique and self-consistent beam model. For example, the measured dosimetric penumbra in water may be attributed in various proportions to the lateral secondary electron range, the focal spot size and the transmission through the tips of a non-divergent collimator; the head-scatter component in the tails of the transverse profiles may not be easy to resolve from phantom scatter and head leakage; and the head-scatter tails corresponding to a certain extra-focal source model may not agree self-consistently with in-air output factors measured on the central axis. To reduce the number of adjustable variables in beam ...

International Nuclear Information System (INIS)

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the ...

International Nuclear Information System (INIS)

GaAs1-xPx p-n junction structures were grown on the epi-ready n-type GaAs(100) substrate by solid source MBE system for different phosphor compositions. To obtain the lattice-match sample structure was applied graded growth procedure. The structural and optical properties of the sample structures with different P concentration were investigated by using X-ray diffraction (XRD), spectroscopic ellipsometry (SE). In addition, The range of lattice parameters in the graded epilayer and phosphorous composition were determined from the HRXRD rocking curve simulation. We analyse dielectric function spectra of disordered GaAs1-xPx junction structures measured using spectroscopic ellipsometry at room temperature in the 0.6-4.7 eV photon energy region. The critical energy points such as band gap energy and spin-orbit-split energy of these structures were determined using SE data. It is detected that E0, E1 ,E2 energies of the GaAs1-xPx p-n junction ...

Energy Technology Data Exchange (ETDEWEB)

Both x-ray and optical cone-beam CT (CBCT) scanners are limited by scattered photons that contaminate the primary images. Transparent radiochromic gels and plastics are anticipated to produce less scattering than polymerization gels and hence result in reconstructed dose distributions with greater contrast and dynamic range. Four methods of scatter measurement were investigated to quantify scatter fractions using an in-house optical CBCT scanner. The methods consisted of generating either 'coin' shadows or primary beamlets in transmission images. The four methods generated similar results of 10% scatter fractions in gel transmission images for this particular scanner configuration with both leuco crystal violet and carbon black micelle gels. The scatter contributions were distributed as 5% from micelle gel, 2% from Teflon wall, 2% from refractive index matching liquid and 1% other sources. Applying a uniform background ...

International Nuclear Information System (INIS)

Here we describe the use of low energy plasma immersion with active screen as a convenient approach for polypropylene (PP) surface modification. Employing a stainless steel cathodic cage coated with carbon in order to prevent the sputtering of iron from the grid and its deposition onto the polymer sample, the physical chemical properties of PP surface could be effectively modified through the plasma-induced incorporation/formation of nitrogen- and oxygen-containing species. The areal densities of these elements depended on the plasma excitation source, as determined by Rutherford backscattering spectrometry (RBS). Newly formed C-O, C-N, and C=O/O=C-O/N-C=O bonds along with C-C linkages from the PP backbone were identified at the near surface region of the specimens by X-ray photoelectron spectroscopy (XPS). The insertion of such polar reactive functionalities was further confirmed by a substantial decrease in the water contact angle upon plasma ...

International Nuclear Information System (INIS)

A combination of measuring instruments, consisting of a Beta-Sedimeter and a radionuclide X-ray fluorescence instrument, is described. With the Beta-Sedimeter the C-14-radiation is measured. Through direct irradiation with photons of a Pu238-source in an ancillary irradiation chamber and energy dispersing measurement of the K- and L-radiation resp. of the excited heavy metals with the aid of a Si(Li)-semiconductor detector and a 4-channel analyzer the heavy metal concentrations of the heavy metals Zn, Cr, Ni and Pb are determined. For the determination of cadmium the indirect excitation with Am-241 and Dy-targets is described. The system produces records and operates fully automatically in a step-by-step mode with a testing cycle of 45 minutes. In connection with the process monitoring of the wastewater from a zinc plating plant during a period of 8 months the concentration of the solid material and of the metals Cr and Zn, which were ...

CERN Document Server

The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges where both electrons ...

CERN Document Server

Radio, optical and X-rays telescopes are improving our knowledge of deep space. All these telescopes detect electromagnetic radiation at various frequencies. But a different kind of radiation is generated in the deeper space; it is the gravitational one. Gravitational waves change the space-time metric. As a consequence, GW telescopes should detect an extremely small strain (h < 10/sup -21/) of the geometry of a reference frame; if the frame has a reference dimension (L) of some kilometers, the deformation amplitude ( Delta L = h * L) is limited to 10/sup -16/ meters. Laser interferometers are the most suitable devices to make precise measurements of distances. Their resolution is limited by the laser wavelength ( lambda = 10/sup -6/ meters) and by the light wave-shift detection capability ( Delta Phi = 1 ppb). These theoretical limits are strongly degraded by different noise sources, which reduce the actual resolution by several orders of ...

CERN Document Server

One of the most interesting discoveries of the X-ray Telescope and EUV Imaging Spectrometer (EIS) on board the Hinode solar observatory is the presence of persistent high temperature high speed outflows from the edges of active regions. Measurements by EIS indicate that the outflows reach velocities of 50 km/s with spectral line asymmetries approaching 200 km/s. It has been suggested that these outflows may lie on open field lines that connect to the heliosphere, and that they could potentially be a significant source of the slow speed solar wind. A direct link has been difficult to establish, however. In this letter, we use EIS measurements of spectral line intensities that are sensitive to changes in the relative abundance of Si and S as a result of the first ionization potential (FIP) effect, to measure the chemical composition in the outflow regions of AR 10978 over a period of 5 days in December 2007. We find that Si is always enhanced ...

International Nuclear Information System (INIS)

There is growing interest in the generation and characterization of femtosecond and subfemtosecond pulses from linac-based free-electron lasers (FELs). In this report, following the method of Ricci and Smith (Phys. Rev. ST Accel. Beams 3, 032801 (2000)), we investigate the measurement of the longitudinal bunch profile of an ultrashort electron bunch produced by these FELs. We show that this method can be applied in a straightforward manner at x-ray FEL facilities such as the Linac Coherent Light Source by slightly adjusting the second bunch compressor followed by running the bunch on an rf zero-crossing phase of the final linac. We find that the linac wakefield strongly perturbs the measurement, and through analysis show that it can be compensated in a simple way. We demonstrate the effectiveness of this method and wakefield compensation through numerical simulations, including effects of coherent synchrotron radiation and longitudinal space ...

Energy Technology Data Exchange (ETDEWEB)

Strong perpendicular anisotropy systems consisting of Co/Pt multilayer stacks that are antiferromagnetically coupled via thin Ru or NiO layers have been used as model systems to study the competition between local interlayer exchange and long-range dipolar interactions [1,2]. Magnetic Force Microscopy (MFM) studies of such systems reveal complex magnetic configurations with a mix of antiferromagnetic (AF) and ferromagnetic (FM) phases. However, MFM allows detecting surface stray fields only and can interact strongly with the magnetic structure of the sample, thus altering the original domain configuration of interest [3,4]. In the current study they combine magnetometry and state-of-the-art soft X-ray transmission microscopy (MXTM) to investigate the external field driven FM phase evolution originating from the domain boundaries in such antiferromagnetically coupled perpendicular anisotropy films. MXTM allows directly imaging the perpendicular ...

Energy Technology Data Exchange (ETDEWEB)

The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa-peri-hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from {sup 1}H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing {pi}-{pi} intermolecular contact in the hexakis-substituted FHBC 4. For bis-substituted FHBC compounds 5 and 6, ...

International Nuclear Information System (INIS)

A family of industrial irradiators is being developed by AECL to cover an electron-beam energy range from 5 to 18 MeV at beam powers between 20 and 250 kW. The IMPELA family of irradiators is designed for push button, reliable operation. The major irradiator components are modular, allowing for later upgrades to meet increased demands in either electron or X-ray mode. Interface between the control system, irradiator availability and dose quality assurance is in conformance with the most demanding specifications. The IMPELA irradiators use a klystron-driven, standing-wave, L-band accelerator structure with direct injection from a rugged, triode electron gun. Direct control of the accelerating field during the beam pulse ensures constant output beam energy, independent of beam power. The first member of the family, the IMPELA 10/50 (10 MeV, 50 kW), is in the final stages of assembly at Chalk River Nuclear Laboratories. The IMPELA 10/50 is ...

British Library Electronic Table of Contents (United Kingdom)

PSI has a relatively long tradition in neutron imaging since the first trials were done at its formerly existing research reactor SAPHIR with film methods. This reactor source was replaced after its shutdown in 1994 by the spallation neutron source SINQ in 1996, driven by the 590MeV cyclotron for protons with presently up to 2.3mA beam current. One of the first experimental devices at SINQ was the thermal neutron imaging facility NEUTRA, which was designed from scratch and has been the first device of its kind at a spallation source. Until now, NEUTRA has been successfully in use for many investigations in a wide range of studies covering fuel cell research, environmental behavior of plants, nuclear fuel inspection and the research on cultural heritage objects. It has been the host of PhD ...

Energy Technology Data Exchange (ETDEWEB)

High-spatial-resolution microfocus-based X-ray imaging technology, both real-time and film, has been used to study the thickness variation that occurs in the oxide core of silver-sheathed BSCCO ribbons produced by the powder-in-tube method. This thickness variation (also called ``sausaging``) occurs during incremental rolling and degrades the critical current densities of the ribbons. Using X-ray image data the authors determined the onset and severity of sausaging. Onset occurred at a ribbon thickness of 203 {micro}m, and the severity increased with subsequent rolling reductions. Scanning electron microscopy was used to confirm the X-ray image data. X-ray imaging provides several advantages over more traditional methods for characterizing the superconductors such as optical or scanning electron microscopy. The X-ray imaging provides nondestructive information about the entire width ...

Energy Technology Data Exchange (ETDEWEB)

The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of ...

International Nuclear Information System (INIS)

Some aspects of metrological provision of X-ray radiometric analyzers for mineral raw composition and gamma-gamma-logging equipment are considered. Standard samples (SS) based on the phenol-formaldehyde resin with the introduced quantities calculated of element compositions in the form of oxides and salts are described. Principles of metrological provision developed are used when carrying out state acceptance tests of X-ray radiometric analyzer RAL-M-102 ''Ehkran'' and gamma-gamma-logging equipmnt RSK-102. Economic benefit from introduction of an SS set is #approx# 60-100 thousand roubles per year.

International Nuclear Information System (INIS)

The textbook is primarily intended for radiologic staff and radiologic safety officers and gives information on the current regulatory provisions of the German X-ray Ordinance, applications of X-rays, quality assurance, organisational aspects of film processing and quality requirements of X-rays. An annex lists the guidelines of the Bundesaerztekammer (German National Chamber of Physicians) relating to quality assurance aspects, and further useful information on commercially available film-screen systems, the various associations of physicians in Germany, and requirements and performance of radiation surveys. (vhe).

Energy Technology Data Exchange (ETDEWEB)

Contributions to the population dose due to medical applications of ionising radiation are presented. It appears that contributions due to radiotherapy and X ray diagnosis are of comparable magnitude. To account for the age dependency of the radiation risks, contributions in terms of somatically significant dose equivalent are calculated as 0.3 mSv per caput per annum for X ray diagnosis and as 0.2 mSv per caput per annum for radiotherapy, the latter referring to only doses to organs outside the target volume. (author).