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.

International Nuclear Information System (INIS)

Based on a recently introduced phase X-ray imaging approach, a dual-detector prototype was developed for in-line X-ray phase imaging and phase retrieval utilizing a micro-focus X-ray source and two computed radiography (CR) cassette detectors. The system was built on a horizontal optical rail to facilitate manual adjustment of the positions of the X-ray source, the sample and the detectors. The novel design of the detector-1 is essential, it detects a portion of radiation to form an attenuation image; allows the rest of radiation to reach the detector-2 to form a phase contrast image, and the two images are used to retrieve a phase map. The two detectors are balanced for optimal phase-retrieval with reasonable radiation dose to the object to be imaged. The ...

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)

A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. The authors established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging

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)

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

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 ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

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.

Energy Technology Data Exchange (ETDEWEB)

The principle of radiodiagnosis consists in the fact the X-ray beam is attenuated at different degrees by distinct tissues. For this reason, the anatomical structures have distinct radiological opacities, that produce the radiographic image. The progresses in radiology are related to the development if new radiographic image formation systems that enable an amplification in the quality, with low dose and/or risk to the patient. The objective of this work is the sensitometric valuation of a screen-film combination, that is still the most used, for the standardization, of radiographic images. Thinking about this, were constructed homogeneous phantoms of the chest, skull and pelvis, for the calibration of X-ray beams, with the purpose of obtaining radiographic images of good quality, basing in the routine of a radiodiagnosis service and in the ...

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.

Energy Technology Data Exchange (ETDEWEB)

Portal localization images for high-energy electron beam therapy are necessary to confirm the treatment field by comparing them with a simulation image obtained before treatment or portal verification images after treatment. In this study, portal localization images were acquired using the computed radiography (CR) system and bremsstrahlung X-rays generated in the electron beam irradiations. All images obtained with phantom and the irradiations of in the electron energy of 8, 10, 12 and 15 MeV were feasible for clinical use. The CR system used in this study included general diagnostic imaging cassette and storage phosphor plate, but none of other special devices. The system can usually supply portal localization images, which maintains the quality assurance ...

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)

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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 ...

Energy Technology Data Exchange (ETDEWEB)

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.

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 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 ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

Monochromator stabilization (MOSTAB) is a feedback control system to stabilize an x-ray beam of synchrotron radiation. It applies a feedback voltage to a piezo electric transducer attached to a double-crystal monochromator. We developed MOSTAB modules and examined their performances using SPring-8 beamlines. The x-ray beam position stabilization using MOSTAB was realized simultaneously with the x-ray beam intensity stabilization. As an example of its application, we performed EXAFS measurement with MOSTAB. (author)

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 ...

International Nuclear Information System (INIS)

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

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)

To assess the diagnostic capability Fuji computed radiography (FCR) using a dual side reading system was compared to the conventional radiography using a film-screen system. Twenty-eight patients with lung cancer were examined with a new FCR system (FCR 5501D) and a conventional screen-film system concurrently. FCR utilizes a reading system that detects emissions from dual sides of imaging plate. Chest X-rays were obtained with same exposure factors in both systems. Image qualities of both systems were compared by two radiologists using a five-level score. There were no lesion that FCR images were inferior to film-screen images. The frequency of score +1 or +2 that FCR images were superior to film-screen ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

International Nuclear Information System (INIS)

Digital radiography for diagnosis of chest diseases using Fuji Computed Radiography (FCR) was evaluated. The results were as follows; 1. Compared to the conventional chest X-ray films, various types of image enhancement could be made by manipulation of the digital information such as tone conversion, spatial frequency modification etc. 2. Digital radiography lessens the X-ray exposure dose and will ultimately permit speedy transmission of image data from outlying clinics to central processing hospitals. 3. Digital radiographic images are useful in chest X-ray diagnosis especially in mass surveys for lung cancer and in primary care medicine because of its full imaging capability. (author).

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

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)

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 ...

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)

X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the ...

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 ...

CERN Document Server

Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The INTEGRAL component, ...

International Nuclear Information System (INIS)

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 detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.

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 ...

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. ...

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)

The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.

International Nuclear Information System (INIS)

Neutron radiography and neutron radioscopy are rapidly becoming the valuable tools for nondestructive testing and basic research. The Phoenix Memorial Laboratory has developed a neutron facility capable of both film neutron radiography and real time neutron radioscopy, and has used this facility to study several phenomena of interest to the researchers in many areas. Neutrons can be used for imaging the phenomena that X-ray cannot image, such as the presence, absence or movement of hydrogenous materials inside metals such as aluminum or steel. There are three basic methods for obtaining images using neutrons: high resolution film neutron radiography, real-time neutron radioscopy and transfer film neutron radiography. The neutron radiography facility at Phoenix Memorial Laboratory, the neutron radioscopic imaging systems, the neutron radiographic detectors, ...

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 ...

International Nuclear Information System (INIS)

A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the ...

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. ...

International Nuclear Information System (INIS)

X-ray imaging using asymmetric Bragg reflection in the hard x-ray regime opens the way to improve the spatial resolution limit below 1 #mu#m by magnifying the image before detection, simultaneously providing a strong phase contrast. A theoretical formalism of the imaging process is established. Based on this algorithm, numerical simulations are performed and demonstrate that both Fresnel propagation and Bragg diffraction contribute to contrast formation. The achievable resolution of this technique is investigated theoretically; the results obtained can be used to improve future experimental setups. Furthermore, the minimum detectable phase gradient is estimated, for comparison with other phase sensitive imaging techniques. Results from biological objects demonstrate that the technique is viable for imaging both in two and three dimensions. ...

UK PubMed Central (United Kingdom)

Background and AimsXylem vessels containing gases (embolized) must be refilled with water if they are to resume transport of water through the plant, so refilling is of great importance...Full Text Available

Science.gov (United States)

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

CERN Document Server

Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov telescopes. Significant detections are reported elsewhere for many of these objects. Here, integral flux upper limits for twelve candidate very high energy (VHE; >100 GeV) gamma-ray emitters are presented. In addition, results from HESS observations of four known VHE-bright AGN are given although no significant signal is measured. For three of these AGN (1ES 1101-232, 1ES 1218+304, and Mkn 501) simultaneous data were taken with the Suzaku X-ray satellite.

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 further dose reduction and a systematic quality control (QC). Patients are increasingly ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

A curved crystal X-ray spectrographs of reflection type spherical geometry was required based on the Johann scheme. Due to their high efficiency and resolution, X-ray spectrographs of focusing spectrograph spatial resolution are suitable for detecting weak X-ray spectra in spectrometers for laser fusion research. Spherically bent mica crystal with a radius of curvature of 380 mm was used in the spectrometer. The Bragg angle of the crystal analyzer was 51 degree. The image plate was employed to obtain high spatial resolution and a narrow spectral band width, with an effective area of 30 mm x 80 mm. The designed optical path of the X-ray spectrometer beam was 980 mm long from the source to the crystal and the detector. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, China Academy of Engineering Physics. ...

Energy Technology Data Exchange (ETDEWEB)

An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated.

British Library Electronic Table of Contents (United Kingdom)

The X-ray storage phosphor CsBr:Eu2+ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu2+ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu2+ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu2+-VCs)-centers and X-ray generated MEu-centers. It will be shown that the formation of (Eu2+-O2?)-dipoles at the expense of (Eu2+-VCs)-dipoles, incorporated by thermal annealing in O2-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu2+ with lithium ions, which is accompanied by a complete suppression of the previously observed MEu-cent...

Energy Technology Data Exchange (ETDEWEB)

The meeting was arranged into the following sessions: introductory; advanced ceramics and ceramic composites; ceramic and metal matrix composites; electronic materials and devices; acoustoelasticity, stress, and texture; composites-porosity, strength, and UT propagation; process modeling and monitoring; thermal wave physics; material properties, composites, surfaces, and interfaces; acoustic emission; ferromagnetic materials; new sensors; NDE reliability assessment; elastic wave scattering and propagation; image analysis, data storage, and signal processing; UT transducers; weldments and bonded materials; eddy current models; unified life cycle engineering; x rays, CT, and NMR; eddy current probes and instruments; acoustic microscopy imaging, and reconstruction; signal processing, measurement techniques, and systems; NDE applications of artificial intelligence; crack behavior ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Secondary ion mass spectrometry (SIMS), secondary electron microscopy (SEM) and X-ray analysis have been applied to the measurement of U-bearing particles with the intent of gleaning information concerning their history and/or origin. The lead isotopic abundances are definitive indicators that U-bearing particles have come from an ore-body, even if they have undergone chemical processing. SEM images and X-ray analysis can add further information to the study that may allude to the extent of chemical processing. The presence of 'common' lead that does not exhibit a radiogenic signature is clear evidence of anthropogenic origin. (author)

Energy Technology Data Exchange (ETDEWEB)

This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is ...

CERN Document Server

Radiation damage is considered to be the major problem that still prevents imaging an individual biological molecule for structural analysis. So far, all known mapping techniques using sufficient short wave-length radiation, be it X-rays or high energy electrons, circumvent this problem by averaging over many molecules. Averaging, however, leaves conformational details uncovered. Even the anticipated use of ultra-short but extremely bright X-ray bursts of a Free Electron Laser shall afford averaging over 10^6 molecules to arrive at atomic resolution. Here we present direct experimental evidence for non-destructive imaging of individual DNA molecules. In fact, we show that DNA withstands coherent low energy electron radiation with deBroglie wavelength in the Angstrom regime despite a vast dose of 10^8 electrons/nm^2 accumulated over more than one hour.

Energy Technology Data Exchange (ETDEWEB)

When chest radiographs are obtained using an anti-scatter grid in a mobile x-ray unit by Fuji Computed Radiography (FCR), right lung densities may differ from left lung densities owing to misalignment caused by an oblique x-ray beam. Such misalignment is considered to be caused by factors such as the shape of the bed and angle of the x-ray tube. Misalignment is especially frequent when exposure is carried out in the sitting position. Although a low-ratio grid has been reported to offer improvement, the misalignment is not completely eliminated. Therefore, we used a copper plate without a lattice feature instead of grid, and examined the results. The copper plate was found to have the ability of a grid to eliminate radiation scatter, and, furthermore, to offer the physical capabilities of a grid as determined by Carlin's new grid assessment method. Image quality was demonstrated through contrast ...

International Nuclear Information System (INIS)

Despite its great usefulness in the performance of the recording procedures prescribed by the X-Ray Ordinance the dose-area product is much less frequently measured for X-ray exposures than during fluorscopic examinations. The great multitude of measuring units, mainly on account of different scales of the measuring equipments themselves, is a cause of uncertainty in clinical routine and should be eliminated as far as the circumstances would permit. As the determination of the organ dose is relevant only in very few cases and does not necessarily require previous measurements of the dose-area product, these are of limited practical value in the assessment of individual radiation exposures during radiographic examinations. The measurements may, however, be very helpful in determinations of the radiation dose to the total population, if the future retrievability of the values obtained is ensured. In addition to some measuring values showing past ...

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 ...

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. ...

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 ...

CERN Document Server

Energy Dispersive X-ray Analysis in the Electron Microscope

Energy Technology Data Exchange (ETDEWEB)

Toroidal Alfven eigenmodes (TAE) destabilized by the pressure gradient of energetic alpha particles may expel the alpha particles before thermalization. TAE is important for tokamaks, and for helical systems (stellarators) as well. In CHS (compact helical system) TAE localized in the plasma core are destabilized when the plasma current is induced by co-injection of neutral beams. The observed TAE exhibits a ballooning nature. The internal structure of TAE was measured with a soft X-ray detector. The soft X-ray fluctuations level for TAE is too low to obtain the radial profiles of fluctuation intensities. (Tanaka, M.)

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)

An experiment on the K#beta#/K#alpha# characteristic X-ray intensity ratio in silver was performed at VEC Centre, Calcutta using the #alpha#-beams at energies 40 MeV and 50 MeV employing a Si(Li) detector system on-line. The results show that the K#beta#/K#alpha# X-ray intensity ratio at energies 40 and 50 MeV are 0.215 #+-# 0.006 and 0.216 #+-# 0.006, respectively, which indicates no change with beam energy and in accordance with the earlier reports. The present experiment shows the feasibility of studying the K#beta#/K#alpha# ratios as a function of beam energy in different regions of periodic table. Experiments in elements belonging to the 3d shell and their compounds are suggested to look for the chemical effects and their dependence on #alpha#-energy. (author). 7 refs.

British Library Electronic Table of Contents (United Kingdom)

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...

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 ...

International Nuclear Information System (INIS)

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; 2) approximately equal detection rates were obtained ...

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)

A Digital X-ray imaging system using Compton backscattering has been developed to obtain a cross-sectional profile and mass loss of corroded lap-splices of aging aircraft from density variation. A slit-type camera was designed to focus on a small scattering volume inside the material, from which the backscattered photons are collected by a collimated scintillator detector for interpretation of material characteristics. The cross section of the lap-joint is scanned by moving the scattering volume through the thickness direction of the specimen. The mass loss of each layer has been estimated from a Compton backscatter A-scan to obtain the thickness of each layer including the aluminum sheet, the corrosion layer and the sealant. Quantitative information such as location and width of planar corrosion in the lap splices of fuselages is obtained by deconvolution using a nonlinear least-square error minimization method(BFGS ...

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.

Energy Technology Data Exchange (ETDEWEB)

Conventional radiography has been the accepted nondestructive testing (NDT) method used for many years to either ''accent'' or ''reject'' a field weld in the pipeline industry. However, conventional radiography requires the expense of film, developing chemicals, and manpower for film development. It also normally has a delay of 2 hours or more between when the weld was radiographed and when the radiographic film of the weld is available for interpretation. Over the last few years, a newer approach to performing radiographic testing, called ''realtime'' radiography, has been used in several different types of field inspection operations. The realtime radiography system forms the image with optical imaging in lieu of photographic film. Objectives of this project were: (Task 1) Integration of realtime ...

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 ...

International Nuclear Information System (INIS)

In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality.

Science.gov (United States)

... The constancy of the X-ray intensity ratio for each element in Table 8 as the X-ray tube settings were changed shows the excellent compensating ...

Science.gov (United States)

This investigation describes the technique for the detection of the X-ray fluorescent radiation

CERN Document Server

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the ...

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)

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 ...

International Nuclear Information System (INIS)

In the Wajima lung cancer screening program conducted under the auspices of Kanazawa University Hospital, Fuji Computed Radiography (FCR) was utilized in a new chest radiography trial. The results of the screening program are that the necessity of repeat examinations due to poor image quality are less common and the method enables detection of small pulmonary nodular shadows which are possibly candidates for surgery. Oblique chest X-ray with FCR is remarkably effective for the detection and the identification of small lesions. However, the disadvantage of slow processing and high cost must be fully satisfied if FCR is to become a new imaging modality for mass screening. (author).

International Nuclear Information System (INIS)

Full text: As you know, thin films which generate anomalous big photovoltage (APhV) , as film photo resistive structures made of the combinations of A_2B_6 respond to X-ray and #gamma#- radiations. In this work the influence of X-ray and #gamma#-radiations on the quantity of APhV in the system APhV-film-photoresistor was investigated. Earlier polycrystal films with anomalous photo voltage properties were received only on the clean and flat surface with high isolation property (R>10"1"4 #OMEGA#). We worked out the technology of receiving APhV films CdTe on the surface of the photosensitive film CdS. The main condition under which this effect may be observed is that the lining must be slant concerning to the direction of the motion of evaporated substance's molecular bunch during the growing of the film, i.e. received film must have a dendritic structure. That is why photosensitive film CdS was received with thermo vacuum ...

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

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.

International Nuclear Information System (INIS)

X-ray diffraction enhanced imaging (DEI) is applied to inspect internal structures of weakly absorbing low-Z sample. How to extract phase information from raw images measured in different positions of rocking curve is the key problem of DEI. In this paper, we present an effective extraction method called polynomial curve fitting method, in order to extract accurate information angular in a fast speed. It is com- pared with the existing methods such as multiple-images statistical method and Gaussian curve fitting method. The experiments results on a plastic cylinder and a black ant at the Beijing Synchrotron Radiation Facility prove that the polynomial curve fitting method can obtain most approximate refraction-angle values and its computation speed is 10 times faster than the Gaussian curve fitting method. (authors)

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

An exhaustive compendium of normal and abnormal imaging is presented. The following systems and procedures are illustrated by over 2800 captioned illustrations: liver, spleen, and hepatobiliary imaging; perfusion and ventilation lung imaging; thyroid imaging; salivary gland imaging; bone imaging; brain imaging; radionuclide cisternography; blood flow studies; gallium imaging; nuclear cardiology; and renal imaging. Not included in the atlas are adrenal imaging procedures and emission computed tomography. (ERB)

International Nuclear Information System (INIS)

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 babygrams and abdomen ...

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.

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

Energy Technology Data Exchange (ETDEWEB)

The K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49 less than or equal to Z less than or equal to 82 following electron capture decay and photon excitation using /sup 241/Am and /sup 57/Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K/sub ..beta..//K/sub ..cap alpha../ values on the mode of excitation in the case of Mn and Fe is attributed to chemical effects, while no such dependence is found for the high-Z elements.

CERN Document Server

we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.

Energy Technology Data Exchange (ETDEWEB)

Most of the investigations have a theoretical sustenance based on molecular simulation. The area of application of molecular simulation is very wide, in the Materials Technology Department assigned to the Applied Sciences Management have been treated problems about metallic nano structures, glasses, interfaces, and molecules, to sustain and to explain some of the experimental results. Energy calculations are carried out to determine minimum energy structures, for later on to carry out calculations of some of their properties; as well as the images simulation of Electron microscopy and X-ray diffraction. (Author)

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)

There is significant interest in using computed tomography (CT) for in vivo imaging applications in mouse models of disease. Most commercially available mouse x-ray CT scanners utilize a charge-coupled device (CCD) detector coupled via fibre optic taper to a phosphor screen. However, there has been little research to determine if this is the optimum detector for the specific task of in vivo mouse imaging. To investigate this issue, we have evaluated four detectors, including an amorphous selenium (a-Se) detector, an amorphous silicon (a-Si) detector with a gadolinium oxysulphide (GOS) screen, a CCD with a 3:1 fibre taper and a GOS screen, and a CCD with a 2:1 fibre taper and both GOS and thallium-doped caesium iodide (CsI:Tl) screens. The detectors were evaluated by measuring the modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), stability over multiple exposures, and noise ...

International Nuclear Information System (INIS)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are ...

International Nuclear Information System (INIS)

The authors propose a method for determining the risk of femoral neck fracture in osteoporotic patients that is not based on densitometric techniques. The method is based on a structural analysis performed by a computer on data taken from a single digital anteroposterior projection of the hip. From the image, the effective cross-sectional area and cross-sectional moment of inertia are computed from attenuation principles. Together with other geometric measurements, these data are used in an engineering analysis to compute the yield strength of the proximal femur, under stress applied through the acetabulum in a one-legged stance. An index of fracture risk based on the ratio of estimated yield strength to body weight is proposed. Ultimately it is expected that this work will allow the clinician to estimate hip fracture risk in osteoporotic patient using widely available existing technology, a goal which has eluded bone density-based methods.

UK PubMed Central (United Kingdom)

The issue of beam-induced damage on diffractive hard X-ray optics is addressed. For this purpose a systematic study on the radiation damage induced by a high-power X-ray beam is carried out in both...Full Text Available

International Nuclear Information System (INIS)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm-2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g-1, respectively. The better electrochemical property should be ascribed to the better crystallized ...

CERN Document Server

Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and Gamma-ray detection. The high atomic number of the materials (Z_{Cd} =48, Z_{Te} =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (Eg ~ 1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this overview talk, we summarize (1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and (2) technique for improving energy resolution and photopeak efficiencies. Applications of these imaging detectors in ...

International Nuclear Information System (INIS)

We describe a camera to record coherent scattering patterns with a soft-x-ray free-electron laser (FEL). The camera consists of a laterally graded multilayer mirror, which reflects the diffraction pattern onto a CCD detector. The mirror acts as a bandpass filter for both the wavelength and the angle, which isolates the desired scattering pattern from nonsample scattering or incoherent emission from the sample. The mirror also solves the particular problem of the extreme intensity of the FEL pulses, which are focused to greater than 10"1"4 W/cm"2. The strong undiffracted pulse passes through a hole in the mirror and propagates onto a beam dump at a distance behind the instrument rather than interacting with a beam stop placed near the CCD. The camera concept is extendable for the full range of the fundamental wavelength of the free electron laser in Hamburg (FLASH) FEL (i.e., between 6 and 60 nm) and into the water window. We have fabricated and tested various ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. Imaging ...

Energy Technology Data Exchange (ETDEWEB)

The compound semiconductor system InGaAsN exhibits many intriguing properties which are particularly useful for the development of innovative high efficiency thin film solar cells and long wavelength lasers. The bandgap in these semiconductors can be varied by controlling the content of N and In and the thin films can yet be lattice-matched to GaAs. In the present work, x-ray absorption fine structure (XAFS) and grazing incidence x-ray scattering (GIXS) techniques have been employed to probe the local environment surrounding both N and In atoms as well as the interface morphology of InGaAsN thin films epitaxially grown on GaAs. The soft x-ray XAFS results around nitrogen K-edge reveal that N is in the sp{sup 3} hybridized bonding configuration in InGaAsN and GaAsN, suggesting that N impurities most likely substitute for As sites in these two compounds. The results of In K-edge XAFS suggest a possible ...

International Nuclear Information System (INIS)

... obtain the film thickness for a given x-ray intensity ratio. 2.3 ANALYSING FOR

International Nuclear Information System (INIS)

A prototype electron applicator system providing circular and rectangular fields for use in intraoperative electron beam therapy with a Varian Clinac 18 linear accelerator has been fabricated. The dosimetric properties of this system for a variety of electron-beam energies, applicator sizes, and x-ray collimator settings was documented. Significant findings include: (a) surface dose values are in excess of 90% for electron energies of 12 MeV and above; (b) for the 18-MeV beam, the deepest depth where the central axis dose is 90% of its maximum value is in excess of 50 mm for circular applicators whose diameters are in excess of 5 cm; and (c) the treatment time to deliver 1000 rads ''given dose'' (at a given dose rate of 300 MU/min) is on the order of 3--4 min. Cross-field behavior is acceptable for the intended application and x-ray contamination is less than 4% for any applicator/electron energy ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a normal or band pattern ...

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 ...

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

Science.gov (United States)

... NONDESTRUCTIVE DETERMINATION OF AIRBORNE LEAD PARTICULATES BY THE RADIONUCLIDE X-RAY FLUORESCENCE ANALYSIS. ...

International Nuclear Information System (INIS)

X-ray scattering methods suitable for the investigation of the morphology and chemical composition of self-organized quantum dots and quantum wires are reviewed. Their application is demonstrated in experimental examples showing that a combination of small angle X-ray scattering with high-resolution X-ray diffraction can reveal both the shape and the chemical composition of the self-organized objects. (author)

International Nuclear Information System (INIS)

Published in summary form only.

Science.gov (United States)

Not Available

International Nuclear Information System (INIS)

Phase transformations occuring during cold deformation in hardened #alpha#+#beta# titanium alloy of the Ti-Al-Mo-Zr-Sn-Si system with 10% summary content of alloying elements are studied by X-ray diffraction analysis. Two stages of trapsformation of metastable #alpha#''-phase are found. A conclusiop is made that ability of the alloy containing #alpha#''-phase to cold deformation is determined by the presence of favourable texture, by high degree of metastability and by volume portion of #alpha#''-phase in the alloy structure.

Energy Technology Data Exchange (ETDEWEB)

Depth resolved positron annihilation studies on Pd/Si thin film system have been carried out to investigate silicide phase formation and vacancy defect production induced by thermal annealing. The evolution of defect sensitive S-parameter clearly indicates the presence of divacancy defects across the interface, due to enhanced Si diffusion beyond 870 K consequent to silicide formation. Corroborative glancing incidence X-ray diffraction (GIXRD), Auger electron spectroscopy (AES) and Rutherford backscattering spectrometry (RBS) have elucidated the aspects related to silicide phase formation and Si surface segregation.

International Nuclear Information System (INIS)

The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).

Energy Technology Data Exchange (ETDEWEB)

Central penetrating excisional wounds were made in the corneas of 12 rabbits and 10 trout. The scar tissue and the surrounding cornea were compared using a new method for assessing inorganic elements in the cornea: the scanning electron microscopy and energy dispersive analysis of x-ray (EDAX). Semiquantitative determination of inorganic elements within the range of atomic numbers 9-93 in the periodic system was performed, comparing the relative concentration of those elements in the scar tissue to the surrounding cornea. Results showed that calcium was the only element higher in the healing wound than in the surrounding cornea.

International Nuclear Information System (INIS)

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. (orig.).

International Nuclear Information System (INIS)

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

CERN Document Server

We study the temporal evolution of coronal loops using data from the Solar X-ray Imager (SXI) on board of GOES-12. This instrument allows us to follow in detail the full lifetime of coronal loops. The observed light curves suggest three somewhat distinct evolutionary phases: rise, main, and decay. The durations and characteristic timescales of these phases are much longer than a cooling time and indicate that the loop-averaged heating rate increases slowly, reaches a maintenance level, and then decreases slowly. This suggests that a single heating mechanism operates for the entire lifetime of the loop. For monolithic loops, the loop-averaged heating rate is the intrinsic energy release rate of the heating mechanism. For loops that are bundles of impulsively heated strands, it is an indication of the frequency of occurrence of individual heating events, or nanoflares. We show that the timescale of the loop-averaged heating rate is proportional ...

British Library Electronic Table of Contents (United Kingdom)

In situ synthesis of silver chloride (AgCl) nanoparticles was carried out under ambient conditions in nanoporous bacterial cellulose (BC) membranes as nanoreactors. The growth of the nanoparticles was readily obtained by alternating dipping of BC membranes in the solution of silver nitrate or sodium chloride followed by a rinse step. X-ray diffraction (XRD) patterns indicated the existence of AgCl nanoparticles in the BC and scanning electron microscopy (SEM) images showed that the AgCl nanoparticles well dispersed on the surface of BC and penetrated into the BC network. The AgCl nanoparticle-impregnated BC membranes exhibited high hydrophilic ability and strong antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The preparative proced...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

The problems are discussed of using radionuclide X-ray fluorescence analysis (the most frequently used source is "2"4"1Am) and neutron activation analysis for monitoring the chemical quality of the working environment of a welder. Elements determinable by these methods are listed and the advantages of the methods stated with regard to speed, simplicity and appropriate accuracy of measurement together with commercial availability of the instruments. Welding as a source of harmful substances is assessed by determination of the amount of chromium in aerosols generated by welding austenitic chromium-nickel steels. The described methods allow to obtain a complex image of the chemical nature of welding aerosols and to understand the mechanism of their impact on the human organism. (J.C.).

International Nuclear Information System (INIS)

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

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.

Science.gov (United States)

A Pulsed Radiation Dosimetry System designed to measure radiation produced by particle accelerators is described. The problems associated with total-dose measurement of irregular shaped pulses of ionizing radiation have been simplified. The system responds to extremely narrow pulses of charged particles or X-rays using a pin diode as the detector. Direct readout of dose in rads (Si) is displayed on a 3-1/2 digit digital panel meter. The system will operate in either the multiple-pulse or single-pulse mode. The multiple-pulse mode would be useful in monitoring or tuning a linear accelerator. In the single-pulse mode the system will automatically display total dose of a transient event in real time and hold that measurement indefinitely or until the next measurement is made. The system features an automatic reset in either mode.

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 ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The task of designing high performance X-ray optical systems requires the development of sophisticated X-ray scattering calculations based on rigorous information about the optics. One of the most insightful approaches to these calculations is based on the power spectral density (PSD) distribution of the surface height. The major problem of measurement of a PSD distribution with an interferometric and/or atomic force microscope arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF characterizes the perturbation of the PSD distribution at higher spatial frequencies. Here, we describe a new method and dedicated test surfaces for calibration of the MTF of a microscope. The method is based on use of a specially designed Binary Pseudo-random (BPR) grating. Comparison of a theoretically calculated PSD spectrum of a BPR grating with a spectrum measured with the grating provides the desired ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Manganese model complexes, relevant to the oxygen-evolving complex (OEC) in photosynthesis, were studied with Mn K-edge X-ray absorption near-edge spectroscopy (XANES), Mn Kb X-ray emission spectroscopy (XES), and vibrational spectroscopy. A more detailed understanding was obtained of the influence of nuclearity, overall structure, oxidation state, and ligand environment of the Mn atoms on the spectra from these methods. This refined understanding is necessary for improving the interpretation of spectra of the OEC. Mn XANES and Kb XES were used to study a di-(mu)-oxo and a mono-(mu)-oxo di-nuclear Mn compound in the (III,III), (III,IV), and (IV,IV) oxidation states. XANES spectra show energy shifts of 0.8 - 2.2 eV for 1-electron oxidation-state changes and 0.4 - 1.8 eV for ligand-environment changes. The shifts observed for Mn XES spectra were approximately 0.21 eV for oxidation state-changes and only approximately 0.04 eV for ...

International Nuclear Information System (INIS)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Ill. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further ...

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a ...

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)

Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous ...

Energy Technology Data Exchange (ETDEWEB)

The three-dimensional magnetic structure and reversal mechanism of patterned Co/Pt multilayers, were imaged using complementary Lorentz transmission electron microscopy (LTEM) (in-plane component) and magnetic transmission x-ray microscopy (M-TXM) (perpendicular magnetization). The Co/Pt films with perpendicular anisotropy were patterned by ion irradiation through a stencil mask to produce in-plane magnetization in the irradiated regions. The boundaries of the patterns, defined by the transition from out-of-plane to in-plane magnetization, were found to be determined by the stencil mask, whilst the scale of the magnetic reversal by the physical microstructure. The nucleation fields were substantially reduced to 50 Oe for the in-plane regions and 1 kOe for the perpendicular regions, comparing to 4.5 kOe for the as-grown film. The perpendicular reversals were found to always originate at the pattern boundaries.

International Nuclear Information System (INIS)

TlGaSe_2 compound belongs to group of layered semiconductors of A"3B"3C_2"6-type. Photoelectric and optical properties of TlGaSe_2 single crystals were investigated in detail. Influence of gamma-, electron and neutron radiation on photoelectric properties of TlGaSe_2 single crystals is investigated too. The present work deals with experimental results relative to X-ray dosimetric characteristics of TlGaSe_2 crystals at 300 K. X-ray conductivity and X-ray dosimetric characteristic measurements are carried out in low load resistance regime. The source of X-ray radiation is the installation of X-ray diffraction analysis (URS-55a) with the BCV-2(Cu). Intensity of X-ray radiation (E) is regulated by measurement with current variation in tube at each given value of X-ray radiation dose E (R/min) are measured by crystal dosimeter DRGZ-02. ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The addition of MO{sub x} (M: di- or tri-valent transition metal ion) into cerium dioxide (CeO{sub 2}) enhanced the ability of CeO{sub 2} for the oxygen (O{sub 2})-releasing reaction at lower temperature and swift hydrogen (H{sub 2})-generation reaction. CeO{sub 2}-MO{sub x} (M=Mn, Fe, Ni, Cu) reactive ceramics having high melting points were synthesized with the combustion method from their nitrates for solar H{sub 2} production. The prepared CeO{sub 2}-MO{sub x} samples were solid solutions between CeO{sub 2} and MO{sub x} with the fluorite structure through the X-ray diffractometry measurement. Two-step water-splitting reactions with CeO{sub 2}-MO{sub x} reactive ceramics proceeded at 1573-1773 K for the O{sub 2}-releasing step and at 1273 K for the H{sub 2}-generation step by irradiation of infrared image furnace as a solar simulator. The amounts of O{sub 2} evolved in the O{sub 2}-releasing reaction with CeO{sub 2}-MO{sub x} increased with ...

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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

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)

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

Science.gov (United States)

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

International Nuclear Information System (INIS)

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

Science.gov (United States)

picture will download the highest resolution version available. M51: X-Rays from the Whirlpool Credit: A. Wilson (UMD) et al., CXC, NASA Explanation: Fresh from yesterday's...

International Nuclear Information System (INIS)

Certain applications are described of radionuclide X-ray fluorescence analysis in the ore dressing industry, in the manufacture of building materials, in metallurgy, pharmacy, in the chemical, photographic and paper industries, in space exploration, in archeology and for measuring the thicknesses of thin layers of coatings. (ES).

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... In this paper research aimed at creating a computer vision system to power such an optimal edging and ... ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

International Nuclear Information System (INIS)

Czech May 1979. p. 32-33. Czechoslovakia Benada, J. Spacek, B. Ustav

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

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