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)

In dual-energy projection radiography with double exposures, rapid energy switching is mandatory to eliminate motion artifacts, but it is costly for use in a clinical environment. We developed a system with practical exposure intervals at reasonable cost by modifying a condenser-type X-ray generator. A commercially available system for digital radiography (Fuji Computed Radiography, FCR) was used to subtract images. This report dealt with technical factors to obtain adequate kV and mAs settings in this technique.

International Nuclear Information System (INIS)

Fuji Computed Radiography (FCR) is a new system of digital radiography that is based on the latest computer technologies. We applied this FCR system to the X-ray diagnosis of the laryngeal disease. Twenty patients with various laryngeal diseases were evaluated by both FCR frontal tomography and conventional screen-film frontal tomography under the same exposure condition. Both tomograms were then compared on the subject of the clarity of delineation of laryngeal structures. As the result, FCR tomograms revealed the feature of the laryngeal lumen and cartilages more clearly than conventional tomograms. In addition, energy subtraction method, which is one of FCR image processing systems, was presented as a new technical procedure to extinguish cervical spine shadows in plain anteroposterior laryngeal X-photograph. We stress that FCR system is the suitable ...

International Nuclear Information System (INIS)

A method for the determination of stereotaxic coordinates in radiography, e.g. angiography, pneumoencephalography or digital vascular radiography, is described. A special localization frame containing radiopaque structures and scales defines a diagnostic coordinate system. This frame is fixed to the X-ray-table prior to the radiographic procedure and two projections are obtained at arbitrary angles to each other. The focus-film distances do not have to be fixed. The target coordinates are then determined either by a simple graphical procedure or with the use of a digitizing x-y-table, by a computer. With the computer method the films are placed on the digitizing table and the target and a few reference points are marked using a cursor. From the relative positions the computer calculates the coordinates. With the special head fixation system, coordinates of ...

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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 ...

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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.).

International Nuclear Information System (INIS)

As part of the evolution of computer technology, Fuji Computed Radiography (FCR) has been developed as a new system for radiographical diagnosis. In this system, the X-ray energy is stored on the imaging plate and then converted into digital signals utilizing scanning laser-stimulated luminence. After proper image processing, it offers much more improved information for diagnosis than the conventional film system does. Since April, 1986, we have principally used FCR (System 101) for neurosurgical practice. In this article, we present our recent experience and evaluate its usefulness. (author).

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)

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).

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

Energy Technology Data Exchange (ETDEWEB)

Purpose: Reconstruction of radiation doses for the thoracoabdominal babygram and the abdomen X-ray from radiographic settings and exposure data acquired at Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007; comparison of these dose values with values reported in the literature; recommendation of a reference dose value for the thoracoabdominal babygram. Materials and Methods: The data from all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 1493 thoracoabdominal babygrams and 3632 abdomen X-rays of newborns and young infants. With the computer program PAeDOS, a specific dose reconstruction algorithm was developed. Results: the entrance dose values of thoracoabdominal ...

International Nuclear Information System (INIS)

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the spine taken by FCR are even clearer, even in the cervicothoracic region, where it is usually difficult to obtain clear cervicothoracic films in ...

Energy Technology Data Exchange (ETDEWEB)

A computerized system for monitoring dose-area product (DAP) has been developed for region of interest (ROI) fluoroscopy in which patient exposure is reduced using an x-ray attenuating filter with an aperture. The system includes an IBM compatible computer which is connected through an IEEE-488 interface to an electrometer which measures the charge from a DAP ionization chamber. A digital input/output board connects the computer to the filter placement device to determine whether the filter is in or out of the beam, and to the x-ray generator to determine when the exposure is due to spot filming. The computer logs the DAP from conventional fluoroscopy, ROI fluoroscopy and spot filming separately, applying the appropriate calibration factor for each. Measured DAPs, fluoroscopic DAP rates and exposure times are displayed in real-time. The system has been installed ...

CERN Document Server

CH Cygni is a symbiotic star consisting of an M giant and an accreting white dwarf, which is known to be a highly variable X-ray source with a complex, two-component, spectra. Here we report on two Suzaku observations of CH Cyg, taken in 2006 January and May, during which the system was seen to be in a soft X-ray bright, hard X-ray faint state. Based on the extraordinary strength of the 6.4 keV fluorescent Fe K-alpha line, we show that the hard X-rays observed with Suzaku are dominated by scattering.

International Nuclear Information System (INIS)

Full text: Introduction. Children, especially premature infants and neonates, are at a much higher risk to obtain an X ray induced disturbance of life - particularly cancer. On the one hand this is due to their longer life expectancy and on the other hand it is due to their higher cell proliferation rate. The paediatric radiology unit of the Inselspital Bern recently installed some of the most advanced X ray equipment nowadays available. It is based on the two latest digital technologies: double read computed radiography (CR) and direct digital radiography (DR). Only the implementation of these digital radiography systems permits the digital acquisition and additionally the analysis of acquired data. The systematic analysis of large amounts of biometric data and exposition data is the basis for ...

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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)

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)

Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The anatomical details ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to assess experimentally and clinically the usefulness of Fuji Computed Radiography (FCR) in angiographic examinations. FCR had a spatial resolution with much lower X-ray exposure doses, although the resolution of FCR was generally inferior to conventional films. When a contrast medium of 1% iodine concentration was used, FCR pinpointed a mass 1.5 mm in diameter; and conventional film could detect a mass 2.2 mm in diameter. The contrast of iodine in FCR examinations was stable. A high sensitivity of imaging plate allowed a wide range of visualization. In 148 selective angiographic examinatinons for 138 patients, FCR-subtraction images were superior to conventional film angiography for contrast resolution; it had a high sensitivity in detecting areas, such as the mediastimun and left lobe of the liver, and tumor stains in capillary phase. The capability of FCR arteriogram was as good as film arteriogram even with a half concentration of ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Since April, 1985, we have, in co-operation with the Fuji Film Co., Ltd., used Fuji Computed Radiography (FCR) in the diagnosis of spinal disorders. FCR is a new computed radiographic system which uses an energy-storage phosphorus panel called an ''Imaging Plate'' as an image sensor. The ''Imaging Plate'' can be used to obtain radiographs in exactly the same way as the screen-film combination used in conventional radiography; X-rays are exposed on the ''Imaging Plate'' instead of X-ray film in the conventional fashion, and then the ''Imaging Plate'' is calculated. The processed digital data from the scans is transformed into a picture by means of digital-to-analogue conversion. The pictures are always clear and beautiful. Plain films of the ...

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)

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 ...

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 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).

International Nuclear Information System (INIS)

The L-shell x-ray intensity ratios I(L_#beta#)/I(L_#alpha#) and I(L_#gamma#)/I(L_a_l_p_h_a) for elements with 73 #<=# Z #<=# 83 have been measured at photon incident energies of 17.8, 25.8 and 46.9 keV. The emitted x-rays were measured with a Si(Li) detector system. The results for Re, Pt and Tl are being reported for the first time. A comparison is made of the experimental results with the calculated values obtained by using the theoretical x-ray emission rates, subshell ionisation cross sections, subshell fluorescence yields and Coster-Kronig transition probabilities. The experimental results are in reasonable agreement with the theoretical values. (author).

Energy Technology Data Exchange (ETDEWEB)

NIF target diagnostics are being developed to observe and measure the extreme physics of targets irradiated by the 192-beam laser. The response time of target materials can be on the order of 100ps--the time it takes light to travel 3 cm--temperatures more than 100 times hotter than the surface of the sun, and pressures that exceed 109 atmospheres. Optical and x-ray diagnostics were developed and fielded to observe and record the results of the first 4-beam experiments at NIF. Hard and soft x-ray spectra were measured, and time-integrated and gated x-ray images of hydrodynamics experiments were recorded. Optical diagnostics recorded backscatter from the target, and VISAR laser velocimetry measurements were taken of laser-shocked target surfaces. Additional diagnostics are being developed and commissioned to observe and diagnose ignition implosions, including various neutron and activation diagnostics. NIF's ...

International Nuclear Information System (INIS)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In computed radiography, image processing (tone scale modification and edge enhancement) is possible, and is advantageous portal imaging. When PACS is ...

Science.gov (United States)

A novel phantom has been developed to measure the modulation transfer function (MTF) in 3D for x-ray computed tomography. The phantom consists of three tungsten wires, positioned nearly orthogonal to each other. Simultaneous measurements of the MTF are taken at various locations along the three orthogonal reconstructed planes. Our computed mammotomography (CmT) system uses a Varian Paxscan 2520 digital x-ray detector which can be positioned anywhere in ~2pi steradian band and can have arbitrary trajectories. With a half-cone beam geometry and with the phantom positioned near the center of rotation, projection images are acquired over 360 degrees. Various 3D orbits are evaluated including vertical axis of rotation and saddle. Reconstructions were performed using an iterative ordered-subsets transmission algorithm on rebinned projection images, using various numbers of iterations. Rotation of ...

Energy Technology Data Exchange (ETDEWEB)

The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the {gamma}-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10{sup 6}n/cm{sup 2}s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/{gamma} ratio {approx} 10{sup 6}n/cm{sup 2}mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, a ...

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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.

KoreaScience (Korea)

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The use of nondestructive evaluation (NDE) methods is proposed for characterization of transuranic (TRU) waste stored at the Radioactive Waste Management Complex. These NDE methods include real-time x-ray radiography, real-time neutron radiography, x-ray and neutron computed tomography, thermal imaging, container weighing, visual examination, and acoustic measurements. An integrated NDE system is proposed for characterization and certification of TRU waste destined for eventual shipment to the Waste Isolation Pilot Plant in New Mexico. Methods for automating both the classification waste and control of a complete nondestructive evaluation/nondestructive assay system are presented. Feasibility testing of the different NDE methods, including real-time x-ray radiography, and development of automated waste classification techniques are covered as part of a five year effort designed to ...

Energy Technology Data Exchange (ETDEWEB)

A number of difficult technical challenges need to be solved in the fields of accelerator and free-electron laser (FEL) technologies in order to build an X-ray FEL. One of the tasks well suited to the Advanced Photon Source Low Energy Undulator Test Line (LEUTL) is to take the intermediate step of solving some of the problems of single-pass FEL operation in the ultraviolet range. The existing Advanced Photon Source (APS) linac, in addition to its role of supply positrons for the APS storage ring, will also be used to generate the particle beam for the LEUTL. Here, the design of the magnetic system for the high gain soft x-ray free electron laser is described.

International Nuclear Information System (INIS)

Composite nitrides (such as BN, TiN) are widely used in various industrial applications because of their extreme wear and corrosion resistance, thermal and electrical properties. in order to obtain composite materials with these optimal properties, it is important to elucidate whether any chemical reactions occur at nitride/metal interfaces, e.g., those involving BN-Ti/TiN. Materials of interest include the deposition by PVD of Ti and TiN on BN substrates. Some of these systems were then subjected to varying degrees of physical and thermal alteration. Detailed X-ray photoelectron spectroscopy (XPS) has therefore been rendered of these interfaces using cross-sectional display and sputter etching. Resulting structural and morphological features have been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Diffusion of the nitridation, oxynitride formation and interfacial growth are of general ...

CERN Document Server

Energy Dispersive X-ray Analysis in the Electron Microscope

International Nuclear Information System (INIS)

Present day mammography has not been able to make use of the advantages of digital luminescence radiography because of the limited spatial resolution. The recent development of electromagnetic focusing X-ray tube with effective focal spot sizes from 0.04 to 0.12 mm allows radiographic direct magnification with less geometric blur. It is now possible to combine direct magnification mammography with digital luminescence radiography. By combining high quality storage phosphor screens with an HQ-workstation a spatial resolution of 8 lp/mm is possible for 1.7-fold magnification. For 4-fold spot magnification views spatial resolution can be theoretically increased to approx. 20 lp/mm. One important advantage of digital radiography is the possibility of image-postprocessing. This article presents two sets of standard parameters and three sets of image dependent parameters for better imaging of specific ...

International Nuclear Information System (INIS)

We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.

International Nuclear Information System (INIS)

The two main aspects of the concept proposed by the ICRP in recommendation 26 for the radiation risk, the differentiation of stochastic and non stochastic damages and the qualification of the stochastic risk, are discussed in its consequences for radiation protection in X-ray diagnostics. Quantitative results from the literature serve to demonstrate the risk factors for the various organs and their sum concerning the position of the layer. As special points of somatic risk appeared the mamma and the pelvic region. The particular risk of CT examination is determined by number and position of the layers and the scan parameters of the system. For typical CT examination the resulting risk factors are estimated in comparison with conventional X-ray diagnostics. The somatic risk of CT examination is relatively high and comparable to conventional examination with the highest risk, while the genetic risk - as in conventional ...

International Nuclear Information System (INIS)

The results of experiments received on the plasma focus (PF) device with energy stored equal 4 kJ are represented. Photos of the current plasma sheath (CPS), pre-pinch, sphere-like plasma formations are produced with help of the electron-optical converter contained a gated micro-channel plate (MCP) and the CCD-camera imaging system in the visible region. The redial velocity of the CPS is about 107 cm/s. Neon plasma electron density measured with help of the interferograms in the visible region and the spectra in the soft X-ray region is equals to 3?1018 cm-3. Electron temperature is equal to about 200 eV. Discharge integral photos were obtained with help of the soft X-ray pinhole camera. Pictures with 2 ?s resolution of the plasma luminescence above PF anode region were made by CCD-camera.

British Library Electronic Table of Contents (United Kingdom)

A galactose-specific seed lectin was purified from the legume Spatholobus parviflorus and crystallized using the hanging-drop vapour-diffusion technique. Thecrystals belonged to space group P1, with unit-cell parameters a = 60.998, b=60.792, c = 78.179-, = 101.32, = 91.38, = 104.32. X-ray diffraction data were collected under cryoconditions (100-K) to a resolution of 2.04- using a MAR image-plate detector system mounted on a rotating-anode X-ray (Cu-K) generator. Molecular replacement using legume-lectin coordinates as a search model gave a tetrameric structure.

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 ...

CERN Document Server

With recent and archival Rossi X-Ray Timing Explorer (RXTE) X-ray measurements of the heavily obscured X-ray pulsar EXO 1722-363 (IGR J17252-3616), we carried out a pulse timing analysis to determine the orbital solution for the first time. The binary system is characterized by a_x sin(i) = 101 +/- 3 lt-s and P_orb = 9.7403 +/- 0.0004 days (90% confidence), with the precision of the orbital period being obtained by connecting datasets separated by more than 7 years (272 orbital cycles). The orbit is consistent with circular, and e 61 degrees at the 99% confidence level, the radius of the primary is between 21 R_sun and 37 R_sun, and its mass is less than about 22 M_sun. The acceptable range of radius and mass shows that the primary is probably a supergiant of spectral type B0I-B5I. Photometric measurements of its likely counterpart are consistent with the spectral type and luminosity if the distance to ...

International Nuclear Information System (INIS)

Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author).

International Nuclear Information System (INIS)

The K_#beta#/K_#alpha# X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49<=Z<=82 following electron capture decay and photon excitation using "2"4"1Am and "5"7Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K_#beta#/K_#alpha# values on the mode of excitation in the case of Mn and Fe is attribuited to the chemical effects, while no such dependence is found for the high-Z elements.

International Nuclear Information System (INIS)

The somatic and genetic radiation exposure of patients undergoing Digital Subtraction Angiography (DSA) and traditional Film Arteriography (FA) of cranial, cervical, thoracic and abdominal vascular territories are compared. The radiation doses absorbed within the critical organs - red bone marrow, lung, thyroid gland and female breast - and in the gonads were measured using an anthropomorphic Alderson phantom. A Somatic Dose Index was calculated in order to estimate the somatic radiation risk. The somatic radiation exposure depends upon the location of the critical organs with respect to the entrance site of the x-ray beam, and can be reduced by an appropriate choice of the angiographic projection. Under this condition, the radiation exposure of the patient during DSA can be lower than during FA. For renal DSA an a.p. projection, the use of an abdominal compression device and careful caudal shielding of the field are advocated. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Present day mammography has not been able to make use of the advantages of digital luminescence radiography because of the limited spatial resolution. The recent development of electromagnetic focusing X-ray tube with effective focal spot sizes from 0.04 to 0.12 mm allows radiographic direct magnification with less geometric blur. It is now possible to combine direct magnification mammography with digital luminescence radiography. By combining high quality storage phosphor screens with an HQ-workstation a spatial resolution of 8 lp/mm is possible for 1.7-fold magnification. For 4-fold spot magnification views spatial resolution can be theoretically increased to approx. 20 lp/mm. One important advantage of digital radiography is the possibility of image-postprocessing. This article presents two sets of standard parameters and three sets of image dependent parameters for better imaging of specific ...

CERN Document Server

We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this relation by more than 11 sigma, indicating ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both ...

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed Tomography (X-CT) system are used to determine the flow regime, the instantaneous cross-sectional averaged void fraction, and the time averaged void fraction in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements are obtained for gas flow rates form 0.0 to 30.0 l/min. The flow regimes observed by all three measurement systems via image analysis shows that the results agree well with each other. Both the RTNR and the X-CT systems show that the time averaged and cross-sectional averaged void fraction increases with increasing superficial gas velocity. Time and cross-sectional averaged void fractions determined by the RTNR system agree within ...

International Nuclear Information System (INIS)

We have performed X-ray magnetic diffraction (XMD) experiment of ferromagnets at the Photon Factory (PF) of the High Energy Accelerator Research Organization (KEK) in Tsukuba. In this study, we have upgraded the XMD experimental system in order to apply this method to as many samples as possible. Upgrade was made for (1) the X-ray counting system and related measurement program, (2) the electromagnet, and (3) the refrigerator. The performance of the system was enhanced so that (1) the counting rate capability was improved from 104cps to 105cps, (2) the maximum magnetic field was increased from 0.85T to 2.15T, and (3) the lowest sample temperature was reduced from 15K to 5K. The new system was applied to an orbital ordering compound of YTiO3, and we obtained spin magnetic form factor for the reflection plane (010) perpendicular to the b axis. The magnetic field ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

ScienceCinema

...english ...

International Nuclear Information System (INIS)

The sections and provisions of the X-ray Ordinance of January 8, 1987 are discussed which are of relevance to dental radiology. (DG).

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.

Energy Technology Data Exchange (ETDEWEB)

This work describes a combinatorial model for estimating the reliability of the embedded digital system by means of multi-state function. This model includes a coverage model for fault-handling techniques implemented in digital systems. The fault-handling techniques make it difficult for many types of components in digital system to be treated as binary state, good or bad. The multi-state function provides a complete analysis of multi-state systems as which the digital systems can be regarded. Through adaptation of software operational profile flow to multi-state function, the HW/SW interaction is also considered for estimation of the reliability of digital system. Using this model, we evaluate the reliability of one board controller in a ...

Science.gov (United States)

... image overlap between adjacent tiles. Orthoimagery processed by BAE Systems....

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.

CERN Document Server

The digital library toolkit

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 increased by more ...

CERN Document Server

The $\\bar{K}N$ system at threshold is a sensitive testing ground for low energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we have measured the $K$-series x rays of kaonic hydrogen atoms at the DA$\\Phi$NE electron-positron collider of Laboratori Nazionali di Frascati, and have determined the most precise values of the strong-interaction energy-level shift and width of the $1s$ atomic state. As x-ray detectors, we used large-area silicon drift detectors having excellent energy and timing resolution, which were developed especially for the SIDDHARTA experiment. The shift and width were determined to be $\\epsilon_{1s} = -283 \\pm 36 \\pm 6 {(syst)}$ eV and $\\Gamma_{1s} = 541 \\pm 89 {(stat)} \\pm 22 {(syst)}$ eV, respectively. The new values will provide vital constraints on the theoretical description of the low-energy $\\bar{K}N$ interaction.

Science.gov (United States)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.

International Nuclear Information System (INIS)

An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.

International Nuclear Information System (INIS)

Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph ...

Science.gov (United States)

The K alpha / K beta ratio of Mn KX-rays scattered by metallic samples changed remarkably with the geometry between the sample and the (55)Fe 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. PMID:7280291

Energy Technology Data Exchange (ETDEWEB)

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.

International Nuclear Information System (INIS)

Radiology departments often underestimate the importance of protecting medical data during transmission, including the precautions taken to ensure data protection. In teleradiology, transmitted as well as stored patient data have to be signed digitally according to the currently valid regulation (Roentgenverordnung, RoeV). The DICOM standard facilitates a digital signature. So far, medical image manufacturers only announced to support this security feature. We introduce a solution that extends the feature of digital signing to older modalities. (orig.)

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 ...

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,#theta#) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.

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)

Bremstrahlung Isochromat Spectroscopy (BIS). The XES spectra were collected using a Specs electron gun for the excitation and the XES 350 grating monochromator and channel plate system from Scienta as the photon detection. Spectra were collected in 'normal mode,' where the electron gun kinetic energy (KE) and the energy position of the center of the channel plate were both fixed and the energy distribution in the photon (hv) spectrum was derived from the intensities distributed across the channel plate detector in the energy dispersal direction. The polycrystalline Ce sample was oxidized by exposure to air at ambient pressures. After introduction to the ultra-high vacuum system, the oxidized sample was bombarded with Ar, to clean the topmost surface region and stabilize the surface and near surface regions. Although CeO{sub 2} would be the thermodynamically preferred composition in an oxygen rich environment, the combination ...

Energy Technology Data Exchange (ETDEWEB)

High interelectrode voltage peaks have been observed simultaneously with the emission of hard X-ray bursts from a flash X-ray tube. The magnitude of the voltage peaks may exceed twice the initial charging voltage. It has also been observed that the discharge emits bursts of X-and P-band microwaves radiation which are coincident with the emission of the hard X-ray bursts. The results indicate that the microwaves and X-rays have a common origin in discharge plasma movements and an acceleration model for electrons in the plasma is presented as one possible explanation of the observed phenomena.

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.

Science.gov (United States)

... Topics includes: Formal methods in information engineering, Electronic documents and digital libraries Autonomous robots in embeded systems ...

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, a longitudinal feedback system is required together with other diagnostics. In this paper, we study the possibility of using Coherent Synchrotron Radiation (CSR) from the chicane as a diagnostic tool for bunch length feedback. Studies show that CSR is a good candidate, even for a non-Gaussian, double-horn longitudinal charge distribution as in the LCLS. We further check the possibility for detecting possible microbunching.

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 ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver ...

British Library Electronic Table of Contents (United Kingdom)

Phase relations in the ternary system Ce-Pd-Si have been established for the isothermal section at 800degreeC based on X-ray powder diffraction and EMPA techniques on about 130 alloys, which were prepared by arc-melting under argon or powder reaction sintering. Eighteen ternary compounds have been observed to participate in the phase equilibria at 800degreeC. Atom order was determined by direct methods from X-ray single-crystal counter data for the crystal structures of t8-Ce3Pd4Si4 (U3Ni4Si4-type, Immm; a=0.41618(1), b=0.42640(1), c=2.45744(7)nm), t16-Ce2Pd14Si (own structure type, P4/nmm; a=0.88832(2), c=0.69600(2)nm) and also for t18-CePd1-xSix (x=0.07; FeB-type, Pnma; a=0.74422(5), b=0.45548(3), c=0.58569(4)nm). Rietveld refinements established the atom arrangement in the structures of...

Energy Technology Data Exchange (ETDEWEB)

Short communication.

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.

CERN Document Server

How to build a digital library

CERN Document Server

Digital Library Technology Trends

CERN Document Server

ACM Digital Library [Online database

Energy Technology Data Exchange (ETDEWEB)

Metallic multilayers offer a fantastic playground to investigate elastic stresses in films of nanometer thickness. We will present and discuss a few examples from our recent work on Au-Ni and Ag-Cu systems where we combined plate bending measurements and electron or X-ray diffraction to investigate stress buildup and interfacial mixing. Comparing these two cases we discuss the results with respect to basic parameters like the misfits in lattice parameters and in elastic moduli, the mixing enthalpies and the surface energies.

Energy Technology Data Exchange (ETDEWEB)

Severe pitting corrosion occurred in a horizontal steel pipeline used to transport multiphase fluid, including water, oil, and natural gas, after 2 months of service. The pitting corrosion rate was up to 42 mm/year. Chemical analysis, X-ray diffractometry, and EDAX showed that the corrosion products mainly consisted of Fe9S8, FeCO3, and NaCl. Calcium containing inclusions were also found in the matrix of the steel, which may accelerate corrosion. The early failure was attributed to the high proportion of water, the slow flow velocity, and the use of unqualified material. (Author)

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.

Energy Technology Data Exchange (ETDEWEB)

The capability of screen-film combinations of detection and representation of information is described by the detective quantum efficiency (DQE). The DQE may be calculated from the sensitivity, the gradient of the characteristic curve, the modulation transfer function and the Wiener spectrum. These parameters have been determined for fourteen screen-film combinations and the DQE's have been calculated. It is shown that the low frequency region the DQE does not depend on spatial frequency. This constant level of DQE is mostly dependent on the absorbance of the screens. Consequences from this fact, as well for the manufacturer as for the user of the screens, are discussed.

International Nuclear Information System (INIS)

Formation of basis type texture at rolling of Ti + 6.0% Al + 1.5% V + 1.0% Mo system alloy with initial prismatic texture is investigated by means of X-ray techniques. Variations of mechanical features in titanium alloy sheets depending on temperature-deformation conditions of rolling are investigated. Main conditions for formation of the intensive basis textute in the investigated alloy sheets which provides for isotropic properties in sheet plane and for increased ductility are determined.

Science.gov (United States)

From nuclear science symposium; San Francisco, California, USA (14 Nov 1973). A digital Fourier analyzer was programmed to perform reactor neutron noise analysis measurements and on-line processing of the data to obtain the steady-state reactivity. The system is suitable for recovering cross spectral density with low correlatedsignal component and for repetitive measurements with efficient use of reactor time. (auth)

International Nuclear Information System (INIS)

Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management. (orig.).

International Nuclear Information System (INIS)

Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)

CERN Document Server

Constraints on the original Cardassian model and the modified polytropic Cardassian model are examined from the latest derived 397 Type Ia supernova (SNe Ia) data, the size of baryonic acoustic oscillation peak from the Sloan Digital Sky Survey (SDSS), the position of first acoustic peak of the Cosmic Microwave Background radiation (CMB) from the five years Wilkinson Microwave Anisotropy Probe (WMAP), the x-ray gas mass fractions in clusters of galaxies, and the observational H(z) data. In the original Cardassian model with these combined data set, we find $\\Omega_{m0}=0.271^{+0.014}_{-0.014}, n=0.035^{+0.049}_{-0.049}$ at $1 \\sigma$ confidence level. And in the modified polytropic Cardassian model, we find that $\\Omega_{m0}=0.271^{+0.014}_{-0.015}$, $n=-0.091^{+0.331}_{-1.908}$ and $\\beta=0.824^{+0.750}_{-0.622}$ within $1\\sigma$ confidence level. According to these observations, the acceleration of the universe begins at ...

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, it is critical to preserve the high quality of the electron beam during acceleration and compression. The peak current and final energy are very sensitive to system jitter. To minimize this sensitivity, a longitudinal feedback system on the bunch length and energy is required, together with other diagnostics and feedback systems (e.g., on transverse phase space). Here, we describe a simulation framework, which includes a realistic jitter model for the LCLS accelerator system, the RF acceleration, structure wakefield, and second order optics. Simulation results show that to meet the tight requirements set by the FEL, such a longitudinal feedback system is mandatory.

International Nuclear Information System (INIS)

The semiconducting compound CuGa_xIn_1_-_xSe_2 crystallizes in the chalcopyrite structure (space group Ianti 42d, Z=4). The X-ray powder data for x=1, 0.75, 0.6, 0.5, 0.4, 0.25 and 0.0 have been collected and it is found that the lattice parameters a and c and their ratio c/a vary linearly with x. Thus the composition of any chalcopyrite in the pseudo-binary system CuGaSe_2 and CuInSe_2 can be obtained from the accurate lattice parameters. The crystallite size determined from the (112) plane is minimum for x=0.50 (#propor to#1000 A) and away from x=0.50 it increases. A value of u=0.240 (5) has been established for fixing, the Se-atom positions in the CuGa_0_._5In_0_._5Se_2 solid solution. The JCPDS Diffraction File No. for CuInSe_2 is 40-1487 and for CuGa_0_._5In_0_._5Se_2 is 40-1488. (orig.).

CERN Document Server

We explore the relationship between the hard X-ray photon index $\\Gamma$ and the Eddington ratio (\\xi=L_{X}(0.5-25 keV)/L_{Edd}) in six XRBs. We find that different XRBs follow different anti-correlations between $\\Gamma$ and $\\xi$ when $\\xi$ is less than a critical value, while they follow the same positive correlation when $\\xi$ is larger than the critical value. This anti-correlation and positive correlation are also found in LLAGNs and QSOs respectively, and the anti-correlation and positive correlation of different XRBs roughly converge to the same point ($\\log \\xi=-2.1, \\Gamma=1.5$), which may correspond to the accretion mode transition, since that the anti-correlation and positive correlation are consistent with the prediction of ADAFs and standard disk/corona system respectively. The traditional low/hard state are divided into two parts by the cross point $\\log \\xi\\sim-2.1$, i.e., faint-hard state in the anti-correlation ...

International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI ...

CERN Document Server

Determining the type of matter that is inside a neutron star (NS) has been a long-standing goal of astrophysics. Despite this, most of the NS equations of state (EOS) that predict maximum masses in the range 1.4-2.8 solar masses are still viable. Most of the precise NS mass measurements that have been made to date show values close to 1.4 solar masses, but a reliable measurement of an over-massive NS would constrain the EOS possibilities. Here, we investigate how optical astrometry at the microarcsecond level can be used to map out the orbits of High-Mass X-ray Binaries (HMXBs), leading to tight constraints on NS masses. While previous studies by Unwin and co-workers and Tomsick and co-workers discuss the fact that the future Space Interferometry Mission should be capable of making such measurements, the current work describes detailed simulations for 6 HMXB systems, including predicted constraints on all orbital parameters. We find that the ...

International Nuclear Information System (INIS)

The shell integrity near peak compression of spherical implosions using the 60-beam, 30-kJ UV OMEGA laser system [Opt. Commun. 133, 495 (1997)] has been measured. Hot core emission backlights a shell with a thin titanium-doped layer that is imaged at x-ray photon energies above and below the titanium K edge. The x-ray intensity ratio between the two images is related to perturbations in the cold, or absorbing, part of the shell. The measured cold-shell areal-density modulations, integrated over the time of peak compression, are of the order of 25% to 50% with nonuniformity spectra peaked at spatial wavelengths of 30 to 50 #mu#m and with the smallest detectable nonuniformity features extending down to spatial wavelengths of 12 to 15 #mu#m. Hot-shell areal-density modulations of the emitting part of the shell (inner edge) are of the order of 13% to 20%. The measured shell modulations are in agreement with the results of ...

Science.gov (United States)

A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.

Energy Technology Data Exchange (ETDEWEB)

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) [Deutsch] Das vorliegende Lehrbuch, das sich vor allem an das technische Personal und an Strahlenschutzbeauftragte wendet, unterrichtet ueber die derzeit gueltigen Bestimmungen der Roentgenverordnung, die Anwendung von Roentgenstrahlen, ueber Qualitaetssicherung, die Organisation der ...

Energy Technology Data Exchange (ETDEWEB)

Glasses in the system (1 - x) [29Na{sub 2}O- 4Al{sub 2}O{sub 3}- 67B{sub 2}O{sub 3}]- xZnO (0 {<=} x {<=} 35 mol%), have been prepared by the melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of ZnO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increases and the molar volume decreases while both sound velocities and the determined glass transition temperatures decrease with increase in x. X-ray and infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of ZnO content. These results are interpreted in terms of the decrease in the N{sub 4} values (fraction of ...

Science.gov (United States)

... Science, Computer Vision, Digital Government, Digital Libraries, Digital Society and Technologies ... for Robust Intelligence, Digital Government, and Digital Libraries and Archives. In subsequent years ...

UK PubMed Central (United Kingdom)

We describe a decision support system to distinguish among hematology cases directly from microscopic specimens. The system uses an image database containing digitized specimens from normal...Full Text Available

International Nuclear Information System (INIS)

Since the PWR plants in Japan have been operated more than 30 years, main instrumentation control equipment of analog systems has been renewed to digital control systems. Renewal works had to be done in short period within periodical inspection term and for several facilities. The Mitsubishi LTD group had been provided with these market needs by its digital control system (MELTAC-NplusR 3) applicable to main instrumentation control equipment for primary and secondary systems and had already finished the renewal for practical plants. (T. Tanaka)

Energy Technology Data Exchange (ETDEWEB)

Information glut is one of the primary characteristics of the electronic age. Managing such large volumes of information (e.g., keeping track of the types, where they are, their relationships, who controls them, etc.) can be done efficiently with an intelligent, user-oriented information management system. The purpose of this paper is to describe a concept for managing information resources based on an intelligent information technology system developed by the Argonne National Laboratory for managing digital libraries. The Argonne system, Intelligent Query (IQ), enables users to query digital libraries and view the holdings that match the query from different perspectives.

International Nuclear Information System (INIS)

The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically

International Nuclear Information System (INIS)

An imaging position sensitive detector for charged particles, neutrons, X-and gamma rays has been developed. The novel feature of this scintillation imaging radiation detector is its ability to detect individual nuclear particle scintillations with a h igh degree of spatial resolution. The key elements of this detector system are a high gain, low noise image intensifier tube, a CCD camera and commercially available image processing hardware and software. This detector system is highly effective for applications such as low fluence and real time neutron radiography, mapping of radioactive contamination in nuclear reactor fuel rods, X-ray diffraction imaging, high speed autoradiography and in general position sensitive detection of nuclear radiation. Results of some of the exploratory experiments carried out using this detector system are presented in this paper. (orig.).

Energy Technology Data Exchange (ETDEWEB)

This paper describes the development and testing of a system to provide isolated power to the cathode-subsystem electronics of an x-ray tube. These components are located at the cathode potential of several hundred kilovolts, requiring a supply of power isolated from this high voltage. In this design a fiber-optically connected photonic power system (PPS) is used to recharge a lithium-ion battery pack, which will subsequently supply power to the cathode-subsystem electronics. The suitability of the commercially available JDSU PPS for this application is evaluated. The output of the ppe converter is characterized. The technical aspects of its use for charging a variety of Li-Ion batteries are discussed. Battery charge protection requirements and safety concerns are also addressed.

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.

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 ...

International Nuclear Information System (INIS)

Exploration for epithermal Au has been active lately in the Aegean Sea of the eastern Mediterranean Basin, both in the islands of the Quaternary arc and in those of the back-arc region. The purpose of this study was the structural mapping and analysis for a preliminary investigation of possible epithermal gold mineralization, using remotely sensed data and techniques, structural and field data, and geochemical information, for a specific area on the Island of Lesvos. Therefore, Landsat-TM and SPOT-Pan satellite images and the Digital Elevation Model (DEM) of the study area were processed digitally using spatial filtering techniques for the enhancement and recognition of the geologically significant lineaments, as well as algebraic operations with band ratios and Principal Component Analysis (PCA), for the identification of alteration zones. Statistical rose diagrams and a SCHMIDT projection Stereo Net were generated from the lineament maps and ...

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. Such an FEL requires a high energy, high brightness electron beam to drive the FEL instability to saturation. When fed by an RF-photocathode gun, and modified to include two bunch compressor chicanes, the SLAC linac will provide such a high quality beam at 14 GeV and 1-{micro}m normalized emittance. In this paper, we report on recent linac studies, including beam stability and tolerances, longitudinal and transverse feedback systems, conventional and time-resolved diagnostics, and beam collimation systems. Construction and installation of the injector through first bunch compressor will be completed by December 2006, and electron commissioning is scheduled to begin in January of 2007.

British Library Electronic Table of Contents (United Kingdom)

Flue gas desulfurization systems (FGDs) are operated in severely corrosive environments that cause sulfuric acid dew-point corrosion. The corrosion behavior of low-alloy steels was tested using electrochemical techniques (electrochemical impedance spectroscopy, potentiodynamic tests, potentiostatic tests), and the corrosion products were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical results showed that alloying W with small amounts of Sb, Cu, and Co improves the corrosion resistance of steels. The results of surface analyses showed that the surface of the steels alloyed with W consisted of W oxides and higher amounts of Sb and Cu oxides. This suggests that the addition of W promotes the formation of a protective WO3 film, in addition to ...

International Nuclear Information System (INIS)

Acceptance testing of mammographic imaging systems technical is the first approach in order to guarantee that mammograms will be achieved with the minimum radiation dose compatible with an image quality suitable for diagnose purposes. The aim of this study is to assess the practical applicability of different protocols in acceptance test of digital mammographic systems. This study has been carried out on the results of the acceptance tests of five flat panel digital mammographic systems. Parameters established in the systems technical specifications and those evaluated in the consulted protocols were tested. Due to the fact that the legislation in our country does not demand to consider a specific protocol, the results obtained were also compared considering different existing protocols. Results show discrepancies between manufacturers limiting values and those ...

UK PubMed Central (United Kingdom)

PurposeThe goal of this study was to clarify the dynamics of tumor oxygen (partial pressure of oxygen, pO₂) in SCC VII murine tumors in mice after X-ray...Full Text Available

UK PubMed Central (United Kingdom)

The disulfide-reduced form of bovine ribonuclease A (RNAse A), with the Cys thiols irreversibly blocked, was characterized by small-angle x-ray scattering (SAXS). To help resolve the conflicting...Full Text Available

International Nuclear Information System (INIS)

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. (author).

Energy Technology Data Exchange (ETDEWEB)

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{sub {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{sub {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)

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and...Full Text Available

International Nuclear Information System (INIS)

Method for description of X-ray radiation dose distribution based on semiempirical description of dose fields is suggested. At that dose field description parameters can be easily individualized for concrete X-ray device.

International Nuclear Information System (INIS)

Differential phase-contrast X-ray imaging has been performed in a Talbot-Lau configuration, where a multiline X-ray source was used instead of a combination of a hard-X-ray multiple slit and a normal focus X-ray generator. When the multiple slit is used, a high aspect ratio structure is needed and slit width should be below 10 ?m for its function. The fabrication and use of such a multislit can be omitted using the presented configuration. The multiline X-ray source was developed by making grooves on a tungsten rotating anode, which was irradiated by an electron beam to generate X-rays. An array of 10?m line sources with a pitch of 30?m was formed and combined with a 4.5 ?m pitch phase grating and a 5.3 ?m pitch amplitude grating to generate differential phase contrast. With a total exposure time of 40 s, a differential phase image depicting cartilages was ...

International Nuclear Information System (INIS)

A photon-induced x-ray fluorescence method allowing the simultaneous determination of iron, copper, zinc, bromine and rubidium in human blood and blood plasma samples is described. The method is reliable and has a good sensitivity for a wide range of elements. (author).

International Nuclear Information System (INIS)

K_#beta#/ K_#alpha# x-ray intensity ratio of chromium were measured in different chromium compounds. The results show the variation of the intensity ratio as a function of the chemical environment around the metal ion. (author)

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 generally well described ...

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)

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

International Nuclear Information System (INIS)

(1972). USSR Sviryakin, DI Manets, AI Kolupaev, AN v. 213 p. 111-114.

Science.gov (United States)

The progress in the development of a surface analysis tool based on the excitation of characteristic

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.).

International Nuclear Information System (INIS)

A number of procedures in diagnostic radiology and cardiology make use of long exposures to x-rays from fluoroscopy units. Although numerous studies have been performed to measure or calculate skin dose from these procedures, there have only been a handful of studies to determine the dose to the other organs. This thesis was focused on devising a method to calculate the absorbed dose to underlying tissues and organs. The work was performed in several stages. First, a commercial convolution/superposition-based treatment planning system used in radiation oncology was modified and complemented to make it usable with the low energies of x-rays used in diagnostic radiology. This required generation of energy deposition kernels in the kilovoltage energy range. The kernels were generated using the EGS4 Monte Carlo system of codes and added to the treatment planning system. The treatment ...

Energy Technology Data Exchange (ETDEWEB)

This article reviews briefly a range of the latest monitoring and controlling equipment for use in coal mines. This includes pressure transmitters, shale/coal discriminator, nucleonic bunker level indicator, automatic steering and monitoring system, oscilloscope/multimeter, and microprocessor based digital display controllers. 1 fig.

Science.gov (United States)

Digital libraries play a crucial role in distance learning. Nowadays, they are one of the fundamental information sources for the students enrolled in this learning system. These libraries contain huge amount of instructional data (text, audio and video) offered by the distance learning program. Organization of the digital libraries is therefore very important for easy and fast access to the desired information. Improper categorization of data may mislead the students searching the library. Since manual categorization of huge amount of data might be challenging, an automatic and reliable method is needed. In this sense, this paper proposes an automated categorization scheme for digital libraries in distance learning. The categorization scheme is designed and developed by a pattern recognition approach. Effectiveness of the proposed scheme is evaluated on widely used Reuters database. The ...

International Nuclear Information System (INIS)

These proceedings represent papers presented at the Astrophysics Conference in Maryland, USA. The topic of the Conference was the evolution of x-ray binaries and the papers encompass a wide range of subjects on x-ray astronomy. There were one hundred eighteen papers presented at the Conference and out of these three have been abstracted for the Energy Science and Technology database.

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.

Science.gov (United States)

The achievement of inner-shell photoionization of Zn-like Pd by means of two exploding foils is described. This resulted in the soft X-ray transition 3d94s2-3d104p at 46 A. It is shown that the photoionization of inner shell electrons in highly stripped ions can lead to X-ray transitions which may be candidates for X-ray lasers under 50 A.

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.

International Nuclear Information System (INIS)

The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.

Energy Technology Data Exchange (ETDEWEB)

New experiment of radiography in using Fuji Intelligent Diagnostic X-ray System was first reported in XV International Congress of Radiology, 1981. By utilizing this system instead of traditional screen/film system, high density imaging plate in conjunction with computed image processor was developed, this is FCR. However, as the numerous problems in regard to the basic side of FCR system are found, it is expected that these are solved by investigators at their earliest opportunities. The purpose of this study is to reduce the radiation doses of the patients at radiography of the chest by using FCR system installed in our Department of Radiology in July, 1984. Experimentally we measured the radiation doses of the patient having the each breast of 18, 20, 22 and 24cm in thickness at radiography of the chest by using VICTOREEN MODEL 666 survey meter. The results ...

Energy Technology Data Exchange (ETDEWEB)

A register transfer language is used to present the basic concepts of computer hardware architecture. Material needed for understanding computer organisation, design, and programming is included. The various functional units of digital computers (central processor, microprogram control; arithmetic algorithms; input-output; and memory organisation), are examined. A basic computer is developed to demonstrate the components of computer hardware and software architecture. Parallel processing and multiprocessor systems are discussed. Numerous MSI and LSI digital functions are introduced with explanations of their characteristics. Cache memory and the hardware requirements for a memory management unit are covered.

Science.gov (United States)

digital libraries, which was identified as a national challenge in the Information ... The linkages between the many digital libraries and information services are ...

Energy Technology Data Exchange (ETDEWEB)

Elevation of zinc protoporphyrin (ZPP) levels in the blood has served as an indicator of lead poisoning and iron deficiency anemia for many years. We have discovered that sublethal doses of whole body irradiation with x-rays also elevates ZPP 2-3-fold over normal levels. The ZPP level does not begin to increase until days 12-14 postirradiation and peaks between days 18 and 20 before returning to normal levels between days 28 and 35. Increasing the radiation dose delays the onset of the rise in ZPP, but does not affect the magnitude of the elevation. At lethal doses, ZPP elevation is not observed. Neither of the two previously described mechanisms that cause elevations of ZPP, namely iron deficiency and inhibition of ferrochelatase, are responsible for the radiation-induced elevation of ZPP. The elevation of ZPP appears to be correlated with the recovery of the hematopoietic system from radiation injury.

International Nuclear Information System (INIS)

The determination of optical parameter type in x-ray pelvimetry was performed on 59 subjects using Fuji computed radiography (FCR). Excellent measurable images were obtained at GT (type A), RT (type P), GA (1.6) and RN (2.0). To reduce maternal and fetal exposure to radiation, the doses were progressively decreased to 50%, 25%, 12.5%, 6.3%, that of conventional screen/film system. One-eighth per cent of conventional radiation dose was minimum for FCR at which measurable images could be obtained. Thereby drastically reducing the radiological exposure to both mother and fetus was possible to obtain measurable images in FCR. (author).

International Nuclear Information System (INIS)

Phase and structural transformations in a multicomponent (5.05 mas.% Mo-4.95V-3.00Cr-3.05Al) metastable #beta#-titanium alloy on aging after plastic deformation are studied using methods of electron microscopy and X-ray diffraction analysis. The alloy is deformed by twinning in a #left brace#332#right brace# system, and even at initial stages the formation of a twin skeleton takes place in the structure, on further loading the deformation of the skeleton is by secondary twinning resulting in a high plasticity of the alloy. On annealing mechanical twins transform into #alpha#-phase - a ductile twin skeleton is replaced by a rigid skeleton of #alpha#-phase plates. The aging enhances the yield strength of the alloy but decreases sharply its plasticity

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction grows exponentially.

British Library Electronic Table of Contents (United Kingdom)

A protective film has been developed on the surface of carbon steel in low chloride aqueous environment using a synergistic mixture of an environmentally friendly phosphonic acid, N,N-bis(phosphonomethyl) glycine (BPMG), and zinc ions. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the chosen environment. Potentiodynamic polarization studies showed that the inhibitor is a mixed inhibitor. X-ray photoelectron spectroscopic analysis (XPS) of the film showed the presence of the elements iron, phosphorus, nitrogen, oxygen, carbon, and zinc. Deconvolution spectra of these elements in the surface film showed the presence of oxides/hydroxides of iron(III), Zn(OH)2, and [Zn(II)-BPMG] complex. This infe...

British Library Electronic Table of Contents (United Kingdom)

The growth of silver chloride nanoparticles on ancient textile was achieved by sequential dipping steps in alternating bath of potassium chloride and silver nitrate under ultrasound irradiation. The effect of ultrasound irradiation and sequential dipping steps in growth of the AgCl nanoparticles has been studied. These systems depicted a decrease in the particles size accompanying a decrease in the sequential dipping steps. The samples were characterized with powder X-ray diffraction (XRD) and scanning electron microscopy. XRD analyses indicated that the prepared AgCl nanoparticles on fiber were crystalline. The textile samples containing AgCl nanoparticles were tested for their antibacterial efficacy against Escherichia coli and were found to possess significant antibacterial activity.

Energy Technology Data Exchange (ETDEWEB)

The microstructure evolution of nine samples from three Ir-base ternary systems, Ir-Nb-Hf, Ir-Nb-Ta, and Ir-Nb-Ti, was investigated by microstructure observation using scanning electron microscopy (SEM), composition map-analysis using electron probe microscopy analysis (EPMA), and phase determination using X-ray diffraction (XRD) patterns. The fcc/L1{sub 2} two-phase structure was detected in all the samples. Lattice misfits between fcc and L1{sub 2} phases were calculated. Ir-Nb-Ta and Ir-Nb-Ti alloys exhibited a microstructure quite similar to that of Ni-base superalloys, and the cuboidal L1{sub 2} precipitates in Ir-Nb-Ta and Ir-Nb-Ti alloys could maintain up to 1900 {sup o}C.

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.

Energy Technology Data Exchange (ETDEWEB)

Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.

British Library Electronic Table of Contents (United Kingdom)

The transformation mechanism of hexagonal delta phase from the disordered bcc gamma phase has not been reported before in the Zr-rich U-Zr alloy system. With the help of X-ray diffraction, transmission electron microscopy (TEM) and high-resolution TEM analyses it was shown that the gamma to delta conversion takes place by the lattice collapse mechanism of omega transformation. It was also ascertained that a higher aging temperature or time promotes the growth of all four variants of the delta phase within a parent gamma grain. In addition, ab initio electronic structure calculations showed that the bcc to hexagonal transformation, involving partial ordering of the parent bcc phase followed by (111) plane collapse, is energetically favorable.

Energy Technology Data Exchange (ETDEWEB)

MRI is a powerful diagnostic modality of expanding availability. Equipment and installation amount to nearly $2M per site. An important component of diagnostic efficacy is not just equipment costs but also replacement costs, which for x-ray CT amount to 14-20% of the purchase cost per year; and in the early years of that technology reached 30-50%. The authors show how design choices made during the RandD stages of MRI development have allowed them to improve system performance parameters such as data reconstruction, archiving and display speeds, computational capabilities, operator interfaces, imaging sequence flexibility and signal-to-noise levels. Over the last four years these improvements have been made at a retrofit cost well below the target of 6-7% of the purchase price per year.

Energy Technology Data Exchange (ETDEWEB)

Since 1979, scientists and engineers at the Los Alamos National Laboratory have designed, constructed, and operated a radio-frequency (RF) linac free-electron laser (FEL) at wavelengths from 9 to 45 /mu/m. Coupled with success of other research centers investigating wavelengths from the visible to far-infrared, Los Alamos is now proposing a vacuum-ultraviolet and soft x-ray (referred to henceforth as extreme ultraviolet, (XUV)) FEL oscillator/Self-Amplified Spontaneous Emission amplifier with beam energies ranging from 100 MeV to 1 GeV. This paper will focus on the first milestone of the proposed Los Alamos XUV project, i.e., a 250-MeV linac with approximately 50 mA of average current, producing photons with wavelengths below 1000 /angstrom/. 3 refs., 3 figs.

CERN Document Server

We describe a method of determining the system parameters in non-eclipsing interacting binaries. We find that the extent to which an observer sees the shape of the Roche-lobe of the secondary star governs the amount of distortion of the absorption line profiles. The width and degree of asymmetry of the phase-resolved absorption line profiles show a characteristic shape, which depends primarily on the binary inclination and gravity darkening exponent. We show that, in principle, by obtaining high spectral and time resolution spectra of quiescent cataclysmic variables or low mass X-ray binaries in which the mass-losing star is visible, fitting the shape of absorption line profiles will allow one to determine not only the mass function of the binary, but also the binary inclination and hence the mass of the binary components.

Energy Technology Data Exchange (ETDEWEB)

Authors developed a C-arm type radiosurgery system of the linear accelerator suitable for stereotactic radiation therapy and a software for arranging 3-dimensional therapy in the system. In this system, the gantry far conical irradiation of 4 MV (0.6-3 Gy/min) and 6 MV (0.9-4.5 Gy/min) X ray or electron beam for the therapy was connected to a newly designed C-arm and was made capable of rotating around either of the axes crossing vertically. With this system, it became unnecessary to move the bed table of the patient for getting suitable distribution of radiation dose. The local accuracy which was measured by the CCD videocamera on the gantry, was within 0.5 mm from the radiation center. The system made it possible to shorten the irradiation time and to improve the local accuracy of irradiating site. The clinical trial was begun from June, ...

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.

Energy Technology Data Exchange (ETDEWEB)

An x-ray diffraction technique for determining thin-film thickness is presented which should prove to be a valuable alternative to the array of spectroscopies (Rutherford backscattering spectrometry, Auger electron spectroscopy, etc.) currently favored for these measurements. Some of the virtues of this x-ray diffraction approach are its nondestructive nature, fast data acquisition rate (enabling in situ observations), thickness resolution better than 5 nm, and conventional equipment requirements. Results are shown for Pd/sub 2/Si thin films grown during isothermal annealing of Pd coatings (100 nm) on Si at 200 /sup 0/C for various amounts of time. A comparison of these x-ray measurements with Rutherford backscattering spectrometry data taken from the same specimens is used to demonstrate the validity of the x-ray technique.

Energy Technology Data Exchange (ETDEWEB)

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 using a method of ...

Science.gov (United States)

The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the ...

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 ...

Energy Technology Data Exchange (ETDEWEB)

The peak flux relationship between hard X-rays and microwaves from solar flares is studied using about 400 events simultaneously recorded with the hard X-ray burst spectrometer on the SMM satellite and the Nobeyama 17 GHz radiometer. The data indicate that the hard X-ray and microwave peak fluxes correlate best for X-ray energies of less than about 80 keV for impulsive flares and greater than about 360 keV for extended flares. By postulating that electrons responsible for microwave emission at 17 GHz are those emitting hard X-rays at these photon energies, it is concluded that: (1) in impulsive flares, microwaves at about 20 GHz are emitted mainly by electrons of less than about 200 keV from a layer through which the electrons stream down into the thick-target hard X-ray source; and (2) in extended flares, microwaves are emitted mainly by MeV electrons trapped ...

International Nuclear Information System (INIS)

We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curve, modulation transfer function (MTF), Wiener spectrum (WS), noise equivalent quanta (NEQ)) for Cannon's flat-panel detector (FPD), Fuji computed radiography (FCR) and screen-film (S/F) systems, respectively. First, the digital and overall characteristic curves of FPD and FCR systems were more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of FPD system were better than those of FCR system a little at lower spatial frequencies than 0.8 mm"-"1, but the overall MTF of FPD and FCR systems were worse than that of S/F system a little at all spatial frequencies. Third, the digital and overall WS of FPD system were similar or ...

Energy Technology Data Exchange (ETDEWEB)

In this two chapter report, instrumentation used to collect seismic data is described. This data acquisition system has two parts: (1) portable anolog seismic recorders and related ``hand-held-testers`` (HHT) and (2) portable digitizing units. During the anolog recording process, ground motion is sensed by a 2-Hz vertical-component seismometer. The voltage output from the seismometer is split without amplification and sent to three parallel amplifier circuit boards. Each circuit board amplifiers the seismic signal in three stages and then frequency modulates the signal. Amplification at the last two stages can be set by the user. An internal precision clock signal is also frequency modulated. The three data carrier frequencies, the clock carrier frequency, and a tape-speed compensation carrier frequency are summed and recorded on a recorded on a cassette tape. During the digitizing process, the cassette tapes are played ...

CERN Document Server

Low noise, high resolution and high dose efficiency are the common requirements for most X-ray imaging applications. Especially in medical applications the dose efficiency is a necessity for detector systems. We present the imaging performance of the Medipix2 readout chip bump bonded to a 300 mu m thick Si detector as a function of the detection threshold, a free parameter not available in conventional integrating imaging systems. Spatial resolution has been measured using the modulation transfer function (MTF) and it varies between 8.2 Ip/mm and 11.0 Ip/mm at 70%. An associated measurement of noise power spectrum (NPS) permits us to derive the detective quantum efficiency (DQE) which can be as a high as 25.5 % for a broadband incoming spectrum. The influence of charge diffusion in the sensor together with threshold variation in the readout chip is discussed. Although the Medipix2 system is used in ...

International Nuclear Information System (INIS)

The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 crystallizes in the trigonal system with space P31m (No. 157), a=b=8.7134(12) A, c=5.2807(11) A and ?=90o, ?=90o, ?=120o, Z=1, ?=3.516 g/cm3. It is a layered structure that is very flat and strongly parallel to c. The V5O14 layer structure consists of corner-linked square and triangular pyramids. The layers are separated by Rb+ ions, which fit equally well on the V5O14 layer. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of Rb3V5O14 is about two times that of KDP. -- Graphical abstract: The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. ...

Energy Technology Data Exchange (ETDEWEB)

We performed a comparative study of digitally and conventionally acquired images in gastrointestinal examinations. Radiation dose and spatial resolution were determined in a water phantom. In 676 examinations with either conventional or digital imaging (system: Diagnost 76, DSI) the number of images and the duration of the fluoroscopy time were compared. 101 examinations with digital as well as conventional documentation were evaluated by using 5 criteria describing the diagnostic performance. The entrance dose of the DSI is 12% to 36% of the film/screen system and the spatial resolution of the DSI may be better than that of a film/screen system with a speed of 200. The fluoroscopy time shows no significant difference between DSI and the film/screen technique. In 2 of 4 examination modes significantly more images were produced by the DSI. With exception of the ...