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Sample records for methods thornback ray

  1. Characterization and isolation of DNA microsatellite primers in Raja clavata L. (thornback ray, Rajidae)

    NARCIS (Netherlands)

    Chevolot, M; Reusch, TBH; Boele-Bos, S; Stam, WT; Olsen, JL

    The thornback ray, Raja clavata, is an elasmobranch (cartilaginous fish). Since the 1950s, its stock has severely declined. In order to investigate the genetic population structure of the species, we developed microsatellite loci. The five loci reported here have eight to 48 alleles per locus and

  2. Modelling the spatial distribution of plaice ( Pleuronectes platessa), sole ( Solea solea) and thornback ray ( Raja clavata) in UK waters for marine management and planning

    Science.gov (United States)

    Maxwell, D. L.; Stelzenmüller, V.; Eastwood, P. D.; Rogers, S. I.

    2009-04-01

    Species distribution maps are needed for ecosystem-based marine management including the development of marine spatial plans. If such maps are based on predictive models then modelling procedures should aim to maximise validation success, and any uncertainty in the predictions needs to be made explicit. We developed a predictive modelling approach to produce robust maps of the distributions of selected marine species at a regional scale. We used 14 years of survey data to map the distributions of plaice, sole and thornback ray in three hydrographic regions comprising parts of the Irish Sea, Celtic Sea and the English Channel with the help of the hybrid technique regression kriging, which combines regression models with geostatistical tools. For each species-region combination we constructed logistic Generalized Linear Models (GLMs) based on presence-absence data using the environmental variables: depth, bottom temperature, bed shear stress and sediment type, as predictors. We selected GLMs using the mean squared error of prediction (MSEP) estimated by cross-validation then conducted a geostatistical analysis of the residuals to incorporate spatial structure in the predictions. In general, we found that species occurrence was positively related to shallow areas, a bed shear stress of between 0 and 1.5 N/m 2, and the presence of sandy sediment. Predicted species occurrence probabilities were in good agreement with survey observations. This modelling framework selects environmental models based on predictive ability and considers the effect of spatial autocorrelation on predictions, together with the simultaneous presentation of observations, associated uncertainties, and predictions. The potential benefit of these distribution maps to marine management and planning is discussed.

  3. Multiple paternity analysis in the thornback ray Raja clavata L.

    NARCIS (Netherlands)

    Chevolot, Malia; Ellis, Jim R.; Rijnsdorp, Adriaan D.; Stam, Wytze T.; Olsen, Jeanine L.

    2007-01-01

    Skates (Rajidae) are characterized by slow growth rate, low fecundity, and late maturity and are thus considered to be vulnerable to exploitation. Although understanding mating systems and behavior are important for long-term conservation and fisheries management, this aspect of life history is

  4. Multiple paternity analysis in the Thornback Ray Raja clavata L.

    NARCIS (Netherlands)

    Chevolot, M.; Ellis, J.R.; Rijnsdorp, A.D.; Stam, W.T.; Olsen, J.L.

    2007-01-01

    Skates (Rajidae) are characterized by slow growth rate, low fecundity, and late maturity and are thus considered to be vulnerable to exploitation. Although understanding mating systems and behavior are important for long-term conservation and fisheries management, this aspect of life history is

  5. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  6. X-ray and gamma ray waveguide, cavity and method

    International Nuclear Information System (INIS)

    Vali, V.; Krogstad, R.S.; Willard, H.R.

    1978-01-01

    An x-ray and gamma ray waveguide, cavity, and method for directing electromagnetic radiation of the x-ray, gamma ray, and extreme ultraviolet wavelengths are described. A hollow fiber is used as the waveguide and is manufactured from a material having an index of refraction less than unity for these wavelengths. The internal diameter of the hollow fiber waveguide and the radius of curvature for the waveguide are selectively predetermined in light of the wavelength of the transmitted radiation to minimize losses. The electromagnetic radiation is obtained from any suitable source ad upon introduction into the waveguide is transmitted along a curvilinear path. The waveguide may be formed as a closed loop to create a cavity or may be used to direct the electromagnetic radiation to a utilization site

  7. Gamma ray spectroscopy monitoring method and apparatus

    Science.gov (United States)

    Stagg, William R; Policke, Timothy A

    2017-05-16

    The present invention relates generally to the field of gamma ray spectroscopy monitoring and a system for accomplishing same to monitor one or more aspects of various isotope production processes. In one embodiment, the present invention relates to a monitoring system, and method of utilizing same, for monitoring one or more aspects of an isotope production process where the monitoring system comprises: (A) at least one sample cell; (B) at least one measuring port; (C) at least one adjustable collimator device; (D) at least one shutter; and (E) at least one high resolution gamma ray spectrometer.

  8. X-ray spectrum local method

    International Nuclear Information System (INIS)

    Avdonin, S.A.

    1985-01-01

    General characteristic and bases of X-ray spectrum local method used for qualitative and quantitative analyses of the mineral chemical composition with volumetric locality of several cubic micrometers. The method is based on the excitation in a sample of characteristic and bremsstrahlung spectra by means of a narrow electron beam at 5-50 keV accelerating voltage. Application of the method when studying uranium minerals and ores is considered. The method allows to determine the uranium presence forms in the ores, morphological features of the minerals, mineral microstructure, UO 2 and UO 3 ratios for unhydrous uraninites and pitchblendes and also to determine mineralization age

  9. Two methods for studying the X-ray variability

    NARCIS (Netherlands)

    Yan, Shu-Ping; Ji, Li; Méndez, Mariano; Wang, Na; Liu, Siming; Li, Xiang-Dong

    2016-01-01

    The X-ray aperiodic variability and quasi-periodic oscillation (QPO) are the important tools to study the structure of the accretion flow of X-ray binaries. However, the origin of the complex X-ray variability from X-ray binaries remains yet unsolved. We proposed two methods for studying the X-ray

  10. Method for spatially modulating X-ray pulses using MEMS-based X-ray optics

    Science.gov (United States)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2015-03-10

    A method and apparatus are provided for spatially modulating X-rays or X-ray pulses using microelectromechanical systems (MEMS) based X-ray optics. A torsionally-oscillating MEMS micromirror and a method of leveraging the grazing-angle reflection property are provided to modulate X-ray pulses with a high-degree of controllability.

  11. Coherent methods in X-ray scattering

    International Nuclear Information System (INIS)

    Gorobtsov, Oleg

    2017-05-01

    X-ray radiation has been used to study structural properties of materials for more than a hundred years. Construction of extremely coherent and bright X-ray radiation sources such as free electron lasers (FELs) and latest generationstorage rings led to rapid development of experimental methods relying on high radiation coherence. These methods allow to perform revolutionary studies in a wide range of fields from solid state physics to biology. In this thesis I focus on several important problems connected with the coherent methods. The first part considers applications of dynamical diffraction theory on crystals to studies with coherent X-ray radiation. It presents the design of a high-resolution spectrometer for free electron lasers that should allow to resolve spectral structure of individual FEL pulses. The spectrometer is based on the principle of dynamical diffraction focusing. The knowledge of individual FEL pulse spectra is necessary for understanding FEL longitudinal coherence. In the same part I present quasi-kinematical approximation to dynamical theory which allows to treat analytically phase effects observed in X-ray coherent imaging on nanocrystals. These effects may play a big role when methods such as ptychography are used to study crystalline samples. The second part deals with measurements of FEL coherence properties using intensity - intensity interferometry. Results of several experiments performed at FELs FLASH and LCLS are revealed in this section. I have developed models and theories to explain the behavior observed in experiments on FLASH. These models allowed to extract information about external positional jitter of FEL pulses and secondary beams present in FEL radiation. In the LCLS experiment the Hanbury Brown and Twiss type interferometry was performed on Bragg peaks from colloidal crystal. This did not require additional measurements without the sample and information was extracted directly from diffraction patterns. Therefore intensity

  12. Coherent methods in X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gorobtsov, Oleg

    2017-05-15

    X-ray radiation has been used to study structural properties of materials for more than a hundred years. Construction of extremely coherent and bright X-ray radiation sources such as free electron lasers (FELs) and latest generationstorage rings led to rapid development of experimental methods relying on high radiation coherence. These methods allow to perform revolutionary studies in a wide range of fields from solid state physics to biology. In this thesis I focus on several important problems connected with the coherent methods. The first part considers applications of dynamical diffraction theory on crystals to studies with coherent X-ray radiation. It presents the design of a high-resolution spectrometer for free electron lasers that should allow to resolve spectral structure of individual FEL pulses. The spectrometer is based on the principle of dynamical diffraction focusing. The knowledge of individual FEL pulse spectra is necessary for understanding FEL longitudinal coherence. In the same part I present quasi-kinematical approximation to dynamical theory which allows to treat analytically phase effects observed in X-ray coherent imaging on nanocrystals. These effects may play a big role when methods such as ptychography are used to study crystalline samples. The second part deals with measurements of FEL coherence properties using intensity - intensity interferometry. Results of several experiments performed at FELs FLASH and LCLS are revealed in this section. I have developed models and theories to explain the behavior observed in experiments on FLASH. These models allowed to extract information about external positional jitter of FEL pulses and secondary beams present in FEL radiation. In the LCLS experiment the Hanbury Brown and Twiss type interferometry was performed on Bragg peaks from colloidal crystal. This did not require additional measurements without the sample and information was extracted directly from diffraction patterns. Therefore intensity

  13. X-ray fluorescence method for trace analysis and imaging

    International Nuclear Information System (INIS)

    Hayakawa, Shinjiro

    2000-01-01

    X-ray fluorescence analysis has a long history as conventional bulk elemental analysis with medium sensitivity. However, with the use of synchrotron radiation x-ray fluorescence method has become a unique analytical technique which can provide tace elemental information with the spatial resolution. To obtain quantitative information of trace elemental distribution by using the x-ray fluorescence method, theoretical description of x-ray fluorescence yield is described. Moreover, methods and instruments for trace characterization with a scanning x-ray microprobe are described. (author)

  14. Development of ray tracing visualization program by Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, Kenji; Otani, Takayuki [Japan Atomic Energy Research Inst., Tokyo (Japan); Hasegawa, Yukihiro

    1997-09-01

    Ray tracing algorithm is a powerful method to synthesize three dimensional computer graphics. In conventional ray tracing algorithms, a view point is used as a starting point of ray tracing, from which the rays are tracked up to the light sources through center points of pixels on the view screen to calculate the intensities of the pixels. This manner, however, makes it difficult to define the configuration of light source as well as to strictly simulate the reflections of the rays. To resolve these problems, we have developed a new ray tracing means which traces rays from a light source, not from a view point, with use of Monte Carlo method which is widely applied in nuclear fields. Moreover, we adopt the variance reduction techniques to the program with use of the specialized machine (Monte-4) for particle transport Monte Carlo so that the computational time could be successfully reduced. (author)

  15. Apparatus and method X-ray image processing

    International Nuclear Information System (INIS)

    1984-01-01

    The invention relates to a method for X-ray image processing. The radiation passed through the object is transformed into an electric image signal from which the logarithmic value is determined and displayed by a display device. Its main objective is to provide a method and apparatus that renders X-ray images or X-ray subtraction images with strong reduction of stray radiation. (Auth.)

  16. Coakial gamma ray detector and method therefor

    International Nuclear Information System (INIS)

    Harchol, M.

    1977-01-01

    A coaxial gamma ray detector is fabricated using intrinsic Ge semiconductor material in a geometry whereby full depletion of electrical carriers is prevented within a small region proximate the point of electrical contact thereby allowing greater biasing potentials across the detector and, consequently, providing reduced electronic noise and increased energy resolution

  17. Simulation study on unfolding methods for diagnostic X-rays and mixed gamma rays

    International Nuclear Information System (INIS)

    Hashimoto, Makoto; Ohtaka, Masahiko; Ara, Kuniaki; Kanno, Ikuo; Imamura, Ryo; Mikami, Kenta; Nomiya, Seiichiro; Onabe, Hideaki

    2009-01-01

    A photon detector operating in current mode that can sense X-ray energy distribution has been reported. This detector consists of a row of several segment detectors. The energy distribution is derived using an unfolding technique. In this paper, comparisons of the unfolding techniques among error reduction, spectrum surveillance, and neural network methods are discussed through simulation studies on the detection of diagnostic X-rays and gamma rays emitted by a mixture of 137 Cs and 60 Co. For diagnostic X-ray measurement, the spectrum surveillance and neural network methods appeared promising, while the error reduction method yielded poor results. However, in the case of measuring mixtures of gamma rays, the error reduction method was both sufficient and effective. (author)

  18. Method of manufacture of a cathode ray tube

    International Nuclear Information System (INIS)

    1976-01-01

    This invention reveals the method of manufacturing a cathode ray tube with an electrode system for the excitation of at least two electron beams with special attention given to mounting the electrodes accurately

  19. Gamma Ray Tomographic Scan Method for Large Scale Industrial Plants

    International Nuclear Information System (INIS)

    Moon, Jin Ho; Jung, Sung Hee; Kim, Jong Bum; Park, Jang Geun

    2011-01-01

    The gamma ray tomography systems have been used to investigate a chemical process for last decade. There have been many cases of gamma ray tomography for laboratory scale work but not many cases for industrial scale work. Non-tomographic equipment with gamma-ray sources is often used in process diagnosis. Gamma radiography, gamma column scanning and the radioisotope tracer technique are examples of gamma ray application in industries. In spite of many outdoor non-gamma ray tomographic equipment, the most of gamma ray tomographic systems still remained as indoor equipment. But, as the gamma tomography has developed, the demand on gamma tomography for real scale plants also increased. To develop the industrial scale system, we introduced the gamma-ray tomographic system with fixed detectors and rotating source. The general system configuration is similar to 4 th generation geometry. But the main effort has been made to actualize the instant installation of the system for real scale industrial plant. This work would be a first attempt to apply the 4th generation industrial gamma tomographic scanning by experimental method. The individual 0.5-inch NaI detector was used for gamma ray detection by configuring circular shape around industrial plant. This tomographic scan method can reduce mechanical complexity and require a much smaller space than a conventional CT. Those properties make it easy to get measurement data for a real scale plant

  20. Model independent method to deconvolve hard X-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

    1984-07-01

    A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented.

  1. Novel X-ray Communication Based XNAV Augmentation Method Using X-ray Detectors

    Directory of Open Access Journals (Sweden)

    Shibin Song

    2015-09-01

    Full Text Available The further development of X-ray pulsar-based NAVigation (XNAV is hindered by its lack of accuracy, so accuracy improvement has become a critical issue for XNAV. In this paper, an XNAV augmentation method which utilizes both pulsar observation and X-ray ranging observation for navigation filtering is proposed to deal with this issue. As a newly emerged concept, X-ray communication (XCOM shows great potential in space exploration. X-ray ranging, derived from XCOM, could achieve high accuracy in range measurement, which could provide accurate information for XNAV. For the proposed method, the measurement models of pulsar observation and range measurement observation are established, and a Kalman filtering algorithm based on the observations and orbit dynamics is proposed to estimate the position and velocity of a spacecraft. A performance comparison of the proposed method with the traditional pulsar observation method is conducted by numerical experiments. Besides, the parameters that influence the performance of the proposed method, such as the pulsar observation time, the SNR of the ranging signal, etc., are analyzed and evaluated by numerical experiments.

  2. Method and apparatus for scanning x-ray tomography

    International Nuclear Information System (INIS)

    Albert, R.D.

    1988-01-01

    In a method of producing a tomographic image of a subject that includes the steps of generating X-rays at a moving origin point by directing a charged particle beam to a target surface, deflecting the charged particle beam to travel the origin point through a predetermined raster scan at the surface, detecting variations of X-ray intensity during the course of the raster scan at spaced apart detection points situated at the opposite side of the subject from the origin point, generating a first sequence of data values that is indicative of variations of X-ray intensity at a first of the detection points at successive times during the course of the raster scan and generating at least a second sequence of data values that is indicative of variations of X-ray intensity at a second of the detection points at successive times during the course of the same raster scan, the improvement is described comprising: combining successive individual data values of the first sequence that are generated by X-rays from successive particular locations in the raster scan with at least individual data values of the second sequence that are generated by X-rays from predetermined successive different locations in the same raster scan in order to produce a composite sequence of data values, and producing an image corresponding to at least a portion of the raster scan which depicts variations of the magnitude of successive data values of the composite sequence

  3. Methods of X-ray examination of condylar knee replacement

    International Nuclear Information System (INIS)

    Vavrik, P.

    1988-01-01

    A detailed description is presented of the methodology of X-ray examination of patients with a condylar knee replacement. Preoperative examination includes standard anterio-posterior and lateral projections, axial projection of the patella in 30 deg flexion of the knee, examination of the mechanical axis of the extremity on a 90 x 30 format and the radioscopic assessment of the centre of the hip joint, essential for the correct centering of the knee implant. Immediately after surgery the position of the implant is checked in two standard projections. Another X-ray check is made after six weeks, before partial loading of the joint is permitted. A complete X-ray examination is made prior to the full loading of the knee joint. The methods are also discussed of the X-ray evaluation of complications such as aseptic loosening of the components, infection, instability, fractures. The general solution od these problems is described. The necessity is underlined of the deliberate and qualified indication of X-ray examinations. The basic prerequisites are listed for reducing the present considerable radiation burden of these patients in the course of the many X-ray examinations. (author). 7 figs., 3 tab., 6 refs

  4. Standardized method for reproducing the sequential X-rays flap

    International Nuclear Information System (INIS)

    Brenes, Alejandra; Molina, Katherine; Gudino, Sylvia

    2009-01-01

    A method is validated to estandardize in the taking, developing and analysis of bite-wing radiographs taken in sequential way, in order to compare and evaluate detectable changes in the evolution of the interproximal lesions through time. A radiographic positioner called XCP® is modified by means of a rigid acrylic guide, to achieve proper of the X ray equipment core positioning relative to the XCP® ring and the reorientation during the sequential x-rays process. 16 subjects of 4 to 40 years old are studied for a total number of 32 registries. Two x-rays of the same block of teeth of each subject have been taken in sequential way, with a minimal difference of 30 minutes between each one, before the placement of radiographic attachment. The images have been digitized with a Super Cam® scanner and imported to a software. The measurements in X and Y-axis for both x-rays were performed to proceed to compare. The intraclass correlation index (ICI) has shown that the proposed method is statistically related to measurement (mm) obtained in the X and Y-axis for both sequential series of x-rays (p=0.01). The measures of central tendency and dispersion have shown that the usual occurrence is indifferent between the two measurements (Mode 0.000 and S = 0083 and 0.109) and that the probability of occurrence of different values is lower than expected. (author) [es

  5. Gamma-ray spectra deconvolution by maximum-entropy methods

    International Nuclear Information System (INIS)

    Los Arcos, J.M.

    1996-01-01

    A maximum-entropy method which includes the response of detectors and the statistical fluctuations of spectra is described and applied to the deconvolution of γ-ray spectra. Resolution enhancement of 25% can be reached for experimental peaks and up to 50% for simulated ones, while the intensities are conserved within 1-2%. (orig.)

  6. Direct methods for surface X-ray diffraction

    International Nuclear Information System (INIS)

    Saldin, D. K.; Harder, R.; Shneerson, V. L.; Vogler, H.; Moritz, W.

    2000-01-01

    We develop of a direct method for surface X-ray diffraction that exploits the holographic feature of a known reference wave from the substrate. A Bayesian analysis of the optimal inference to be made from an incomplete data set suggests a maximum entropy algorithm that balances agreement with the data and other statistical considerations

  7. X-ray film cassette and method of making

    International Nuclear Information System (INIS)

    1980-01-01

    An x-ray film cassette which is capable of providing forces on the film that vary across the surface of the cassette is described. Methods of manufacture are discussed. The system is of particular use when large area films are used in conjunction with intensifying screens. (U.K.)

  8. Applications of γ-ray image method to astronomy

    International Nuclear Information System (INIS)

    Wuensche, C.A.; Braga, J.; Jayanthi, U.B.; Villela, T.

    1990-01-01

    The use of codified mask technique in a gamma ray telescope is presented. The image reconstruction method is described showing the mask operation. The signal/noise relation for redundant uniform arrangements which constitute the mask, is discussed. The MASCO telescope is described in detail showing the main characteristics of project. (M.C.K.)

  9. The Random Ray Method for neutral particle transport

    Energy Technology Data Exchange (ETDEWEB)

    Tramm, John R., E-mail: jtramm@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science Engineering, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139 (United States); Argonne National Laboratory, Mathematics and Computer Science Department 9700 S Cass Ave, Argonne, IL 60439 (United States); Smith, Kord S., E-mail: kord@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science Engineering, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139 (United States); Forget, Benoit, E-mail: bforget@mit.edu [Massachusetts Institute of Technology, Department of Nuclear Science Engineering, 77 Massachusetts Avenue, 24-107, Cambridge, MA 02139 (United States); Siegel, Andrew R., E-mail: siegela@mcs.anl.gov [Argonne National Laboratory, Mathematics and Computer Science Department 9700 S Cass Ave, Argonne, IL 60439 (United States)

    2017-08-01

    A new approach to solving partial differential equations (PDEs) based on the method of characteristics (MOC) is presented. The Random Ray Method (TRRM) uses a stochastic rather than deterministic discretization of characteristic tracks to integrate the phase space of a problem. TRRM is potentially applicable in a number of transport simulation fields where long characteristic methods are used, such as neutron transport and gamma ray transport in reactor physics as well as radiative transfer in astrophysics. In this study, TRRM is developed and then tested on a series of exemplar reactor physics benchmark problems. The results show extreme improvements in memory efficiency compared to deterministic MOC methods, while also reducing algorithmic complexity, allowing for a sparser computational grid to be used while maintaining accuracy.

  10. The Random Ray Method for neutral particle transport

    International Nuclear Information System (INIS)

    Tramm, John R.; Smith, Kord S.; Forget, Benoit; Siegel, Andrew R.

    2017-01-01

    A new approach to solving partial differential equations (PDEs) based on the method of characteristics (MOC) is presented. The Random Ray Method (TRRM) uses a stochastic rather than deterministic discretization of characteristic tracks to integrate the phase space of a problem. TRRM is potentially applicable in a number of transport simulation fields where long characteristic methods are used, such as neutron transport and gamma ray transport in reactor physics as well as radiative transfer in astrophysics. In this study, TRRM is developed and then tested on a series of exemplar reactor physics benchmark problems. The results show extreme improvements in memory efficiency compared to deterministic MOC methods, while also reducing algorithmic complexity, allowing for a sparser computational grid to be used while maintaining accuracy.

  11. Background elimination methods for multidimensional coincidence γ-ray spectra

    International Nuclear Information System (INIS)

    Morhac, M.

    1997-01-01

    In the paper new methods to separate useful information from background in one, two, three and multidimensional spectra (histograms) measured in large multidetector γ-ray arrays are derived. The sensitive nonlinear peak clipping algorithm is the basis of the methods for estimation of the background in multidimensional spectra. The derived procedures are simple and therefore have a very low cost in terms of computing time. (orig.)

  12. Geometric estimation method for x-ray digital intraoral tomosynthesis

    Science.gov (United States)

    Li, Liang; Yang, Yao; Chen, Zhiqiang

    2016-06-01

    It is essential for accurate image reconstruction to obtain a set of parameters that describes the x-ray scanning geometry. A geometric estimation method is presented for x-ray digital intraoral tomosynthesis (DIT) in which the detector remains stationary while the x-ray source rotates. The main idea is to estimate the three-dimensional (3-D) coordinates of each shot position using at least two small opaque balls adhering to the detector surface as the positioning markers. From the radiographs containing these balls, the position of each x-ray focal spot can be calculated independently relative to the detector center no matter what kind of scanning trajectory is used. A 3-D phantom which roughly simulates DIT was designed to evaluate the performance of this method both quantitatively and qualitatively in the sense of mean square error and structural similarity. Results are also presented for real data acquired with a DIT experimental system. These results prove the validity of this geometric estimation method.

  13. gamma-ray tracking in germanium the backtracking method

    CERN Document Server

    Marel, J V D

    2002-01-01

    In the framework of a European TMR network project the concept for a gamma-ray tracking array is being developed for nuclear physics spectroscopy in the energy range of approx 10 keV up to several MeV. The tracking array will consist of a large number of position-sensitive germanium detectors in a spherical geometry around a target. Due to the high segmentation, a Compton scattered gamma-ray will deposit energy in several different segments. A method has been developed to reconstruct the tracks of multiple coincident gamma-rays and to find their initial energies. By starting from the final point the track can be reconstructed backwards to the origin with the help of the photoelectric and Compton cross-sections and the Compton scatter formula. Every reconstructed track is given a figure of merit, thus allowing suppression of wrongly reconstructed tracks and gamma-rays that have scattered out of the detector system. This so-called backtracking method has been tested on simulated events in a shell-like geometry ...

  14. γ-ray tracking in germanium: the backtracking method

    International Nuclear Information System (INIS)

    Marel, J. van der; Cederwall, B.

    2002-01-01

    In the framework of a European TMR network project the concept for a γ-ray tracking array is being developed for nuclear physics spectroscopy in the energy range of ∼10 keV up to several MeV. The tracking array will consist of a large number of position-sensitive germanium detectors in a spherical geometry around a target. Due to the high segmentation, a Compton scattered γ-ray will deposit energy in several different segments. A method has been developed to reconstruct the tracks of multiple coincident γ-rays and to find their initial energies. By starting from the final point the track can be reconstructed backwards to the origin with the help of the photoelectric and Compton cross-sections and the Compton scatter formula. Every reconstructed track is given a figure of merit, thus allowing suppression of wrongly reconstructed tracks and γ-rays that have scattered out of the detector system. This so-called backtracking method has been tested on simulated events in a shell-like geometry for germanium and in planar geometries for silicon, germanium and CdTe

  15. Spectrographical method for determining temperature variations of cosmic rays

    International Nuclear Information System (INIS)

    Dorman, L.I.; Krest'yannikov, Yu.Ya.; AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1977-01-01

    A spectrographic method for determining [sigmaJsup(μ)/Jsup(μ)]sub(T) temperature variations in cosmic rays is proposed. The value of (sigmaJsup(μ)/Jsup(μ)]sub(T) is determined from three equations for neutron supermonitors and the equation for the muon component of cosmic rays. It is assumed that all the observation data include corrections for the barometric effect. No temperature effect is observed in the neutron component. To improve the reliability and accuracy of the results obtained the surface area of the existing devices and the number of spectrographic equations should be increased as compared with that of the unknown values. The value of [sigmaJsup(μ)/Jsup(μ)]sub(T) for time instants when the aerological probing was carried out, was determined from the data of observations of cosmic rays with the aid of a spectrographic complex of devices of Sib IZMIR. The r.m.s. dispersion of the difference is about 0.2%, which agrees with the expected dispersion. The agreement obtained can be regarded as an independent proof of the correctness of the theory of meteorological effects of cosmic rays. With the existing detection accuracy the spectrographic method can be used for determining the hourly values of temperature corrections for the muon component

  16. Methods for X-ray examinations of the maxillodental system

    International Nuclear Information System (INIS)

    Rabukhina, N.A.; Arzhantsev, A.P.

    1992-01-01

    Only two roentgenography methods (periapical and occlusion) are used for production of dental roentgenograms. Periapical survey must be used only for revealing state of bone tissue around tooth root tops. In parodontology it is necessary to use occlusion survey. Perfection of the methods and improvement of quality of tooth roentgenograpms demand to change the design of native dental X-ray unit: elongation of its tube, increase of radiator power. Introduction of orthopantomography as basis method of roengenography in stomatology is the most radical decision of methodological problems. Orthopantomography is replaced by intra- and extra-oral roentgenography of teeth and jaws

  17. Method of making a low energy gamma ray collimator

    International Nuclear Information System (INIS)

    Muehllehner, Gerd.

    1975-01-01

    Described herein is a method for making a low energy gamma ray collimator which involves corrugating lead foil strips by passing them through pinion wire rollers and gluing corrugated strips between straight strips using an adhesive such as epoxy to build up a honeycomb-like structure. A thin aluminum sheet is glued to both edges of the strips to protect them and to provide a more rigid assembly which may be sawed to a desired shape. (Patent Office Record)

  18. X-Ray analysis and methods for nondestructive control (On the 100-anniversary of X-ray foundation)

    International Nuclear Information System (INIS)

    Sosnin, F.R.

    1995-01-01

    Brief consideration is given to the history of X-ray discovery, formation of domestic X-ray industry. Principles of operation and potentialities of X-ray diffraction analysis, gammagraphy, radioscopy, radiometric analysis are described briefly. Domestic and foreign scientists, institutes and companies who contributed much to development of methods for nondestructive control are listed

  19. A novel x-ray circularly polarized ranging method

    International Nuclear Information System (INIS)

    Song Shi-Bin; Xu Lu-Ping; Zhang Hua; Shen Yang-He; Gao Na

    2015-01-01

    Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. (paper)

  20. Analysis of fresco paintings by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Cechak, T.; Gerndt, J.; Musilek, L.; Kopecka, I.

    2000-01-01

    In this work we present the application of X-ray fluorescence analysis (XRFA) to examine fresco paintings from the Karlstejn castle. The X-ray fluorescence apparatus built and operated in the Laboratory of Quantitative Methods in Research of Ancient Monuments was used for the purpose of fresco paintings measurements. The X-ray sources (radionuclides) generate the characteristic X-ray photons from the sample. The Si(Li) detector measures numbers and energies of photons emitted from the specimen. The energy and number of photons detected can be converted into kind and amount of measured atoms. These results give data for qualitative and quantitative analysis of samples. XRFA is relatively simple and non-destructive method. Capability of in-situ measurement is one of big advantages of this method. The radionuclide sources of exciting radiation (e.g. 55 Fe enables the excitation of elements with Z up to 23, 238 Pu is used in interval of Z from 20 to 39 etc.) were used. An Si(Li) semiconductor detector with a 5 l Dewar vessel and portable spectroscopy system enable the in situ measurement. Narrow collimation of the exciting beam makes it possible to select the measured area of fresco painting. The valuable fresco paintings from the Karlstejn castle were investigated in this way. The measurements were carried out in collaboration with the Analytical Laboratory of the State Institute for the Preservation of Historic Monuments. A suitable analysis of paintings makes it possible to detect the kind of colours and evaluate changes in the surface colour of paintings and suggest useful and timely procedures for their conservation and restoration. (author)

  1. Method for monitoring drilling materials for gamma ray activity

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Arnold, D.M.; Schultz, W.E.

    1985-01-01

    This invention relates to a method of verifying the radioactivity levels in raw barite prior to its use in drilling mud. Certain gamma ray measurements are taken of the raw barite and extrapolated to a well bore environment using the projected drilling mud weight made from this barite and the dimensions of the well bore. The natural radioactivity occurring in the formations in the vicinity of the well bore is then compared with the projected levels to enable a determination of whether or not the barite has sufficient radioactive trace elements to forbid its use in a well. Alternatively, the method indicates the ratios by which such additives containing radioactive trace elements must be diluted with non-radioactive additives before use in the drilling mud. A second use of the method involves mud testing at the well site for radioactivity from mud additives, including barite, potassium chloride, and well cuttings. Additional uses include testing other weight materials prior to or subsequent to addition to the mud, and methods for correcting observed gamma ray measurements for the mud-induced background

  2. Method of X-ray examination of upper respiratory tracts

    International Nuclear Information System (INIS)

    Portnoj, L.M.; Surenchik, V.I.; Shuster, M.A.; Sal'nikova, Eh.A.

    1982-01-01

    Method of X-ray examination of upper respiratory tracts by radiography both in direct and lateral projection with an introduction of radiocontrast media through tracheostoma is described. The main objective of the invention is to improve accuracy of diagnostics of larynx and trachea cicatrix structures in children. The objective is attained by the examination under general anesthesia; barium sulfate is simultaneously introduced through laryngoscope and tracheostoma, and polypositional radiography is accomplished just in the moment of air introduction under 130-170 mm Hg pressure in the amounts of 60-200 ml

  3. A method to measure the γ-ray content in VHE cosmic ray showers

    International Nuclear Information System (INIS)

    Cresti, M.; Peruzzo, L.; Pesci, A.; Saggion, A.; Sartori, G.; Angelini, F.; Bedeschi, F.; Bellazzini, R.; Bertolucci, E.; Chiarelli, G.; Mariotti, M.; Massai, M.M.; Menzione, A.; Smith, D.A.; Stefanini, A.; Zetti, F.; Scribano, A.; Bartoli, B.; Budinich, M.; Liello, F.; Milotti, E.; Biral, A.R.P.; Chinellato, J.A.; Turtelli, A.; Luksys, M.

    1991-01-01

    An experimental technique is presented to determine the effectiveness of methods to tag photon initiated air showers and reject hadron initiated ones. The technique is based on the rate reduction in the Moon direction. With a photon energy threshold below or equal to 1 TeV, with an angular resolution of a few mrad and being insensitive to visible light, the proposed CLUE detector allows a wide and original physics program. In particular the direct measurement of the fraction of primary photons in the continuum of the cosmic ray flux is feasible with adequate statistics in a few months of data taking. (orig.)

  4. Modified X-ray method of a study of duodenum

    Energy Technology Data Exchange (ETDEWEB)

    Korolyuk, I.P.; Bugakov, V.M.; Shinkin, V.M.

    A modified X-ray examination of duodenum under hypotension conditions is described. In comparison with the existing method, the above-mentioned modification allows one to investigate the duodenum by using double contrast - the high-concentrated barium suspension and the gas, formed after the gasificated powder dose. 327 patients have been examined by the given method, 126 of them have been diagnosed to suffer from inflammatory diseases of the stomach and the duodenum, 22 of them suffering from the duodenum peptic ulcer, 107 of them - pancreatitis, 48-cholelithiasis, 24 - the tumor of the pancreatoduodenum zone. 65 patients have been operated on. Roentgenomorphologic comparisons have been carried out for 66 patients suffering from inflammatory deseases of the duodenum. Duodenum visualization of 283 patients is found to be good and satisfactory. The given method may be used under any conditions, including polyclinics, due to the sparing nature.

  5. Method for monitoring drilling materials for gamma ray activity

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Arnold, D.M.; Schultz, W.E.

    1985-01-01

    In the preferred and illustrated embodiment taught herein, method steps for monitoring of raw materials to be used in drilling mud are disclosed. The materials are monitored for radioactivity. Procedures for taking such measurements are disclosed, and the extent of gamma radioactivity in the raw materials used in drilling mud is, determined. This is correlated to the increased radiation attributable to mud made from these materials and the effect the mud would have on gamma ray measuring logs. An alternate procedure for testing drilling mud, typically at the well site, is also disclosed. The method detects mud radioactivity from any additives including barite, potassium chloride, well cuttings or others. Excessive background levels due to mud gamma radioactivity in a well may very well mask the data obtained by various logging procedures dependent on gamma radiation. Procedures are also described for either rejecting mud which is too radioactive or correcting the log measurements for mud effects

  6. A method of detector correction for cosmic ray muon radiography

    International Nuclear Information System (INIS)

    Liu Yuanyuan; Zhao Ziran; Chen Zhiqiang; Zhang Li; Wang Zhentian

    2008-01-01

    Cosmic ray muon radiography which has good penetrability and sensitivity to high-Z materials is an effective way for detecting shielded nuclear materials. The problem of data correction is one of the key points of muon radiography technique. Because of the influence of environmental background, environmental yawp and error of detectors, the raw data can not be used directly. If we used the raw data as the usable data to reconstruct without any corrections, it would turn up terrible artifacts. Based on the characteristics of the muon radiography system, aimed at the error of detectors, this paper proposes a method of detector correction. The simulation experiments demonstrate that this method can effectively correct the error produced by detectors. Therefore, we can say that it does a further step to let the technique of cosmic muon radiography into out real life. (authors)

  7. Measuring the black hole mass in ultraluminous X-ray sources with the X-ray scaling method

    Science.gov (United States)

    Jang, I.; Gliozzi, M.; Satyapal, S.; Titarchuk, L.

    2018-01-01

    In our recent work, we demonstrated that a novel X-ray scaling method, originally introduced for Galactic black holes (BH), could be reliably extended to estimate the mass of supermassive black holes accreting at moderate to high level. Here, we apply this X-ray scaling method to ultraluminous X-ray sources (ULXs) to constrain their MBH. Using 49 ULXs with multiple XMM-Newton observations, we infer that ULXs host both stellar mass BHs and intermediate mass BHs. The majority of the sources of our sample seem to be consistent with the hypothesis of highly accreting massive stellar BHs with MBH ∼ 100 M⊙. Our results are in general agreement with the MBH values obtained with alternative methods, including model-independent variability methods. This suggests that the X-ray scaling method is an actual scale-independent method that can be applied to all BH systems accreting at moderate-high rate.

  8. A novel x-ray circularly polarized ranging method

    Science.gov (United States)

    Song, Shi-Bin; Xu, Lu-Ping; Zhang, Hua; Gao, Na; Shen, Yang-He

    2015-05-01

    Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. Projects supported by the National Natural Science Foundation of China (Grant Nos. 61172138 and 61401340), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2013JQ8040), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130203120004), the Open Research Fund of the Academy of Satellite Application, China (Grant No. 2014 CXJJ-DH 12), the Xi’an Science and Technology Plan, China (Grant No. CXY1350(4)), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 201413B, 201412B, and JB141303), and the Open Fund of Key Laboratory of Precision Navigation and Timing Technology, National Time Service Center, Chinese

  9. A portable x-ray source and method for radiography

    International Nuclear Information System (INIS)

    Golovanivsky, K.S.

    1996-01-01

    A portable x-ray source that produces a sufficient x-ray flux to produce high quality x-ray images on x-ray films. The source includes a vacuum chamber filled with a heavy atomic weight gas at low pressure and an x-ray emitter. The chamber is in a magnetic field and an oscillating electric field and generates electron cyclotron resonance (ECR) plasma having a ring of energetic electrons inside the chamber. The electrons bombard the x-ray emitter which in turn produces x-ray. A pair of magnetic members generate an axisymmetric magnetic mirror trap inside the chamber. The chamber may be nested within a microwave resonant cavity and between the magnets or the chamber and the microwave cavity may be a single composite structure. (author)

  10. A NEW CLASSIFICATION METHOD FOR GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Lue Houjun; Liang Enwei; Zhang Binbin; Zhang Bing

    2010-01-01

    Recent Swift observations suggest that the traditional long versus short gamma-ray burst (GRB) classification scheme does not always associate GRBs to the two physically motivated model types, i.e., Type II (massive star origin) versus Type I (compact star origin). We propose a new phenomenological classification method of GRBs by introducing a new parameter ε = E γ,iso,52 /E 5/3 p,z,2 , where E γ,iso is the isotropic gamma-ray energy (in units of 10 52 erg) and E p,z is the cosmic rest-frame spectral peak energy (in units of 100 keV). For those short GRBs with 'extended emission', both quantities are defined for the short/hard spike only. With the current complete sample of GRBs with redshift and E p measurements, the ε parameter shows a clear bimodal distribution with a separation at ε ∼ 0.03. The high-ε region encloses the typical long GRBs with high luminosity, some high-z 'rest-frame-short' GRBs (such as GRB 090423 and GRB 080913), as well as some high-z short GRBs (such as GRB 090426). All these GRBs have been claimed to be of Type II origin based on other observational properties in the literature. All the GRBs that are argued to be of Type I origin are found to be clustered in the low-ε region. They can be separated from some nearby low-luminosity long GRBs (in 3σ) by an additional T 90 criterion, i.e., T 90,z ∼< 5 s in the Swift/BAT band. We suggest that this new classification scheme can better match the physically motivated Type II/I classification scheme.

  11. Method for reducing x-ray background signals from insertion device x-ray beam position monitors

    Directory of Open Access Journals (Sweden)

    Glenn Decker

    1999-11-01

    Full Text Available A method is described that provides a solution to the long-standing problem of stray radiation-induced signals on photoemission-based x-ray beam position monitors (BPMs located on insertion device x-ray beam lines. The method involves the introduction of a chicane into the accelerator lattice that directs unwanted x radiation away from the photosensitive x-ray BPM blades. This technique has been implemented at the Advanced Photon Source, and experimental confirmation of the technique is provided.

  12. Precision test method by x-ray absorbent clay

    International Nuclear Information System (INIS)

    Nakadai, Toru; Matsukawa, Hideyuki; Sekita, Jun-ichiro; Murakoshi, Atsushi.

    1982-01-01

    In X-ray penetration photography of such as welds with reinforcing metal and castings of complex shape, the X-ray absorbent clay developed to eliminate various disadvantages of the conventional absorbents was further studied for better application. The results of the usage are as follows. Because the X-ray absorbent is clay, it is flexible in form, and gives good adhesion to test objects. In the welds and castings mentioned, it is effective for reducing the scattered ray, accordingly, it results in superior images. The following matters are described: contrast in radiographs, the required conditions for X-ray absorbents in general, the properties of the absorbent (absorption coefficient, consistency, density), improvement in radiographs by means of the X-ray absorbent clay (wall thickness compensation, masking, the application together with narrow-field irradiation photography). (Mori, K.)

  13. Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

    International Nuclear Information System (INIS)

    Kheymits, M D; Leonov, A A; Zverev, V G; Galper, A M; Arkhangelskaya, I V; Arkhangelskiy, A I; Yurkin, Yu T; Bakaldin, A V; Suchkov, S I; Topchiev, N P; Dalkarov, O D

    2016-01-01

    The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work. (paper)

  14. Quasimonochromatic x-ray computed tomography by the balanced filter method using a conventional x-ray source

    International Nuclear Information System (INIS)

    Saito, Masatoshi

    2004-01-01

    A quasimonochromatic x-ray computed tomography (CT) system utilizing balanced filters has recently been developed for acquiring quantitative CT images. This system consisted of basic components such as a conventional x-ray generator for radiography, a stage for mounting and rotating objects, and an x-ray line sensor camera. Metallic sheets of Er and Yb were used as the balanced filters for obtaining quasimonochromatic incident x rays that include the characteristic lines of the W Kα doublet from a tungsten target. The mean energy and energy width of the quasimonochromatic x rays were determined to be 59.0 and 1.9 keV, respectively, from x-ray spectroscopic measurements using a high-purity Ge detector. The usefulness of the present x-ray CT system was demonstrated by obtaining spatial distributions of the linear attenuation coefficients of three selected samples--a 20 cm diameter cylindrical water phantom, a 3.5 cm diameter aluminum rod, and a human head phantom. The results clearly indicate that this apparatus is surprisingly effective for estimating the distribution of the linear attenuation coefficients without any correction of the beam-hardening effect. Thus, implementing the balanced filter method on an x-ray CT scanner has promise in producing highly quantitative CT images

  15. Trace element analysis of environmental samples by multiple prompt gamma-ray analysis method

    International Nuclear Information System (INIS)

    Oshima, Masumi; Matsuo, Motoyuki; Shozugawa, Katsumi

    2011-01-01

    The multiple γ-ray detection method has been proved to be a high-resolution and high-sensitivity method in application to nuclide quantification. The neutron prompt γ-ray analysis method is successfully extended by combining it with the γ-ray detection method, which is called Multiple prompt γ-ray analysis, MPGA. In this review we show the principle of this method and its characteristics. Several examples of its application to environmental samples, especially river sediments in the urban area and sea sediment samples are also described. (author)

  16. A Simple Method of Spectrum Processing for β-ray Measurement without Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jun Woo; Kim, Hee Reyoung [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    Radioactivity analysis of β-emitting radionuclide is important because of its dangerousness of overexposure. γ-ray has been measured by conventional detector such as NaI(Tl) or high purity germanium (HPGe) detector. But β-ray is hard to detect by those detectors because of its short range. Therefore, liquid scintillation counter (LSC) has been used to measure the radioactivity of pure beta emitter but there is huge problem of organic waste production, though LSC has high efficiency for detection of low energy β-ray. To solve this problem, characterization of β-ray measurement in a plastic scintillator was carried out in this study. There have been some studies about plastic scintillator to measure the β-rays without liquid scintillation method. Plastic scintillator has benefits for detection of β-ray because it has relative low effective atomic number. β-ray and γ-ray spectra in cylindrical plastic scintillator was analyzed and a method of separation of β-ray spectrum was suggested. A simple method of β-ray spectrum separation was suggested. The method was verified by chi-square method to estimate the difference between calculated and measured spectrum. This method was successfully applied by using disc source. For future works, practical radioactive source will be used to acquire the pulse height spectrum. The method can be used for measurement of pure β emitter without pretreatment if this method is verified for practical purpose.

  17. X-ray and synchrotron methods in studies of cultural heritage sites

    Energy Technology Data Exchange (ETDEWEB)

    Koval’chuk, M. V.; Yatsishina, E. B.; Blagov, A. E.; Tereshchenko, E. Yu., E-mail: elenatereschenko@yandex.ru; Prosekov, P. A.; Dyakova, Yu. A. [National Research Centre “Kurchatov Institute” (Russian Federation)

    2016-09-15

    X-ray and synchrotron methods that are most widely used in studies of cultural heritage objects (including archaeological sites)—X-ray diffraction analysis, X-ray spectroscopy, and visualization techniques— have been considered. The reported examples show high efficiency and informativeness of natural science studies when solving most diverse problems of archaeology, history, the study of art, museology, etc.

  18. X-ray and synchrotron methods in studies of cultural heritage sites

    International Nuclear Information System (INIS)

    Koval’chuk, M. V.; Yatsishina, E. B.; Blagov, A. E.; Tereshchenko, E. Yu.; Prosekov, P. A.; Dyakova, Yu. A.

    2016-01-01

    X-ray and synchrotron methods that are most widely used in studies of cultural heritage objects (including archaeological sites)—X-ray diffraction analysis, X-ray spectroscopy, and visualization techniques— have been considered. The reported examples show high efficiency and informativeness of natural science studies when solving most diverse problems of archaeology, history, the study of art, museology, etc.

  19. Translate rotate scanning method for X-ray imaging

    International Nuclear Information System (INIS)

    Eberhard, J.W.; Kwog Cheong Tam.

    1990-01-01

    Rapid x-ray inspection of objects larger than an x-ray detector array is based on a translate rotate scanning motion of the object related to the fan beam source and detector. The scan for computerized tomography imaging is accomplished by rotating the object through 360 degrees at two or more positions relative to the source and detector array, in moving to another position the object is rotated and the object or source and detector are translated. A partial set of x-ray data is acquired at every position which are combined to obtain a full data set for complete image reconstruction. X-ray data for digital radiography imaging is acquired by scanning the object vertically at a first position at one view angle, rotating and translating the object relative to the source and detector to a second position, scanning vertically, and so on to cover the object field of view, and combining the partial data sets. (author)

  20. Feasibility study on X-ray source with pinhole imaging method

    International Nuclear Information System (INIS)

    Qiu Rui; Li Junli

    2007-01-01

    In order to verify the feasibility of study on X-ray source with pinhole imaging method, and optimize the design of X-ray pinhole imaging system, an X-ray pinhole imaging equipment was set up. The change of image due to the change of the position and intensity of X-ray source was estimated with mathematical method and validated with experiment. The results show that the change of the spot position and gray of the spot is linearly related with the change of the position and intensity of X-ray source, so it is feasible to study X-ray source with pinhole imaging method in this application. The results provide some references for the design of X-ray pinhole imaging system. (authors)

  1. Tokamak physics studies using x-ray diagnostic methods

    International Nuclear Information System (INIS)

    Hill, K.W.; Bitter, M.; von Goeler, S.

    1987-03-01

    X-ray diagnostic measurements have been used in a number of experiments to improve our understanding of important tokamak physics issues. The impurity content in TFTR plasmas, its sources and control have been clarified through soft x-ray pulse-height analysis (PHA) measurements. The dependence of intrinsic impurity concentrations and Z/sub eff/ on electron density, plasma current, limiter material and conditioning, and neutral-beam power have shown that the limiter is an important source of metal impurities. Neoclassical-like impurity peaking following hydrogen pellet injection into Alcator C and a strong effect of impurities on sawtooth behavior were demonstrated by x-ray imaging (XIS) measurements. Rapid inward motion of impurities and continuation of m = 1 activity following an internal disruption were demonstrated with XIS measurements on PLT using injected aluminum to enhance the signals. Ion temperatures up to 12 keV and a toroidal plasma rotation velocity up to 6 x 10 5 m/s have been measured by an x-ray crystal spectrometer (XCS) with up to 13 MW of 85-keV neutral-beam injection in TFTR. Precise wavelengths and relative intensities of x-ray lines in several helium-like ions and neon-like ions of silver have been measured in TFTR and PLT by the XCS. The data help to identify the important excitation processes predicted in atomic physics. Wavelengths of n = 3 to 2 silver lines of interest for x-ray lasers were measured, and precise instrument calibration techniques were developed. Electron thermal conductivity and sawtooth dynamics have been studied through XIS measurements on TFTR of heat-pulse propagation and compound sawteeth. A non-Maxwellian electron distribution function has been measured, and evidence of the Parail-Pogutse instability identified by hard x-ray PHA measurements on PLT during lower-hybrid current-drive experiments

  2. Elemental composition of cosmic rays using a maximum likelihood method

    International Nuclear Information System (INIS)

    Ruddick, K.

    1996-01-01

    We present a progress report on our attempts to determine the composition of cosmic rays in the knee region of the energy spectrum. We have used three different devices to measure properties of the extensive air showers produced by primary cosmic rays: the Soudan 2 underground detector measures the muon flux deep underground, a proportional tube array samples shower density at the surface of the earth, and a Cherenkov array observes light produced high in the atmosphere. We have begun maximum likelihood fits to these measurements with the hope of determining the nuclear mass number A on an event by event basis. (orig.)

  3. Characterization of cryogenic materials by x-ray absorption methods

    International Nuclear Information System (INIS)

    Heald, S.M.; Tranquada, J.M.

    1985-01-01

    X-ray absorption techniques have in recent years been developed into powerful probes of the electronic and structural properties of materials difficult to study by other techniques. In particular, the extended x-ray absorption fine structure (EXAFS) technique can be applied to a variety of cryogenic materials. Three examples are used to demonstrate the power of the technique. The first is the determination of the lattice location of dilute alloying additions such as Ta and Zr in Nb 3 Sn. The Ta additions are shown to reside predominately in Nb lattice sites, while Zr is not uniquely located at either Nb or Sn sites. In addition to structural information, temperature dependent EXAFS studies can be used to determine the rms deviations of atomic bond lengths, providing information about the temperature dependence of interatomic force constants. For Nb 3 Sn deviations are found from simple harmonic behavior at low temperatures which indicate a softening of the Nb-Sn bond strength. The final example is the study of interfacial properties in thin film systems. This is accomplished by making x-ray absorption measurements under conditions of total external reflection of the incident x-rays. As some examples show, this technique has great potential for studying interfacial reactions, a process used in the fabrication of many superconducting materials

  4. Sulfur content measurement in coal by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Cechak, T.; Thinova, L.

    2001-01-01

    X-ray fluorescence, using backscattering, was employed in the determination of sulfur content and ash content measurement in coal. The results of the methods are given to illustrate the differences between the chemical analysis and X-ray fluorescence method.

  5. Application of NASVD method in the denoising of airborne gamma-ray data

    International Nuclear Information System (INIS)

    Yang Jia; Ge Liangquan; Zhang Qingxian; Gu Yi

    2010-01-01

    A noise reducing method based on multivariate statistical analysis f or gamma-ray spectra-the NASVD method (Noise Adjusted Singular Value Decomposition), main idea and algorithm for realizing of the NASVD are introduced in the paper. The NASVD method is used to an airborne gamma-ray data set, the result has show n that the method can dramatically remove statistical noise from raw gamma-ray spectra and the quality of processed data is much better than that of the conventional spectral denoising methods. (authors)

  6. Demonstration of a collimated in situ method for determining depth distributions using gamma-ray spectrometry

    CERN Document Server

    Benke, R R

    2002-01-01

    In situ gamma-ray spectrometry uses a portable detector to quantify radionuclides in materials. The main shortcoming of in situ gamma-ray spectrometry has been its inability to determine radionuclide depth distributions. Novel collimator designs were paired with a commercial in situ gamma-ray spectrometry system to overcome this limitation for large area sources. Positioned with their axes normal to the material surface, the cylindrically symmetric collimators limited the detection of un attenuated gamma-rays from a selected range of polar angles (measured off the detector axis). Although this approach does not alleviate the need for some knowledge of the gamma-ray attenuation characteristics of the materials being measured, the collimation method presented in this paper represents an absolute method that determines the depth distribution as a histogram, while other in situ methods require a priori knowledge of the depth distribution shape. Other advantages over previous in situ methods are that this method d...

  7. Two gamma-ray detectors method for examination of fuel elements

    International Nuclear Information System (INIS)

    Kristof, E.; Pregl, G.

    1979-01-01

    Th initial experiment and method for the nondestructive determination of a fuel element burnup is given. The method eliminates the error which originates from the unknown local dependency of the attenuation coefficient for gamma rays in fuel. (author)

  8. Measurement of thickness of thin films by the X-ray diffraction method

    International Nuclear Information System (INIS)

    Srinivasan, C.; Balasingh, C.; Singh, A.K.

    1979-07-01

    X-ray diffraction method can be used to measure the thickness of thin films (coatings). The principle and the experimental details of the x-ray diffraction methods are described. The intensities of the diffracted beams are derived assuming a random orientation of the crystallites in the diffracting medium. Consequently, the expressions are not valid when the sample has preferred orientation. To check the performance of the method, thicknesses of nickel deposits on mild steel plates were determined by the x-ray diffraction method and the results compared with those obtained by the weighing method and metallographic examination. The weighing method which gives an accuracy of +- 0.1 micron is taken as the standard. The x-ray diffraction methods and the metallographic examinations give values within +- 1 micron of the value obtained by the weighing method. (author)

  9. Required doses for projection methods in X-ray diagnosis

    International Nuclear Information System (INIS)

    Hagemann, G.

    1992-01-01

    The ideal dose requirement has been stated by Cohen et al. (1981) by a formula basing on parallel beam, maximum quantum yield and Bucky grid effect depending on the signal to noise ratio and object contrast. This was checked by means of contrast detail diagrams measured at the hole phantom, and was additionally compared with measurement results obtained with acrylic glass phantoms. The optimal dose requirement is obtained by the maximum technically possible approach to the ideal requirement level. Examples are given, besides for x-ray equipment with Gd 2 O 2 S screen film systems for grid screen mammography, and new thoracic examination systems for mass screenings. Finally, a few values concerning the dose requirement or the analogous time required for fluorscent screening in angiography and interventional radiology, are stated, as well as for dentistry and paediatric x-ray diagnostics. (orig./HP) [de

  10. Method and apparatus involving the generation of x-rays

    International Nuclear Information System (INIS)

    Neal, W.R.; Little, R.G.

    1978-01-01

    An electron gun assembly generates an accelerated and sharply focused electron beam which is deflected in a predetermined path to impinge upon an extended split anode structure in a selected scanning pattern with approximately half the beam current impinging on each half of the split anode. A signal proportional to the difference between the two currents from each half of the split anode provides feedback control to the beam deflection system for constraining the beam to follow the fissure of the split anode. X-rays which are generated at the point of beam impingement on the split anode constitute a moving source of x-rays as the point of beam impingement travels in the selected pattern along the anode

  11. Search for antimatter in 1012 eV cosmic rays using Artemis method and interpretation of the cosmic rays spectrum

    International Nuclear Information System (INIS)

    Pomarede, D.

    1999-04-01

    This thesis is divided into three parts. The first part is a review of the present knowledge of the antimatter and of the cosmic rays. Theoretical and experimental aspects are presented. It is demonstrated that a measurement of the antimatter abundance in TeV cosmic rays is of fundamental interest, and would establish the symmetric or asymmetric nature of the Universe. The second part is dedicated to the method of antimatter research through the Earth Moon ion spectrometer (ARTEMIS). The account is given of the winter 1996-97 41-nights observation campaign undertaken at the Whipple Observatory in Arizona (USA). A 109 photomultiplier camera is operated on the 40 meter telescope to detect by Cherenkov imaging the cosmic ray initiated showers. We describe the performance of an optical filter used to reduce the noise. The development and the utilization of a simulation program are described. The main work is the analysis of the data: data characterization, understanding of the apparatus, understanding of the noise and its influence, calibration, search for signals by different methods. Subtle systematic effects are uncovered. The simulations establish that the amount of data is insufficient to reveal a shadow effect in the cosmic ray flux. The conclusion of this work is that the experimental setup was not suitable, and we propose important improvements of the method based on a bigger focal plane that would allow to reach a one percent sensitivity on the antimatter content of the cosmic rays. In the third part of the thesis, an interpretation of the total cosmic ray spectrum is proposed and discussed. (author)

  12. Method and device for X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Jagoutz, E.; Palme, C.

    1978-01-01

    In the x-ray fluorescence analyzer the useful signal can be completely separated from the spurious signals, and especially the pulse can be determined. For this purpose the output of the radiation detector is connected with a multichannel pulse height discriminator. The measured signal determined in the pulse heigth discriminator may be indicated by a visual display or processed by a computer (coincidence circuits). (DG) [de

  13. A method for synthesizing response functions of NaI detectors to gamma rays

    International Nuclear Information System (INIS)

    Sie, S.H.

    1978-08-01

    A simple method of parametrizing the response function of NaI detectors to gamma rays is described, based on decomposition of the pulse-height spectrum into components associated with the actual detection processes. Smooth dependence of the derived parameters on the gamma-ray energy made it possible to generate a lineshape for any gamma-ray energy by suitable interpolation techniques. The method is applied in analysis of spectra measured with a 7.6 x 7.6 cm NaI detector in continuum gamma-ray study following (HI,xn) reaction

  14. Method of making tomographic images of X-rayed objects

    International Nuclear Information System (INIS)

    Eickel, R.

    1979-01-01

    A tomographic image of a selected layer of a stationary object is made by moving the source of X-rays along a first path at one side of the selected layer and by moving an ionography imaging chamber which contains a dielectric receptor sheet along a second path at the other side of the selected layer. The movement of the sheet is synchronized with movement of the source of X-rays and includes a translatory movement in a direction counter to the direction of movement of the source, a pivotal movement to maintain the sheet in a plane which is normal to the central beam of the bundle of X-rays, and a sidewise movement to vary the distance between the selected layer and the sheet so that the length of the projection of selected layer upon the sheet remains unchanged. If the sheet is rectangular, the pivotal movement is performed about an axis which is located in the plane of the selected layer and is parallel to the shorter sides of the sheet

  15. Moving-Article X-Ray Imaging System and Method for 3-D Image Generation

    Science.gov (United States)

    Fernandez, Kenneth R. (Inventor)

    2012-01-01

    An x-ray imaging system and method for a moving article are provided for an article moved along a linear direction of travel while the article is exposed to non-overlapping x-ray beams. A plurality of parallel linear sensor arrays are disposed in the x-ray beams after they pass through the article. More specifically, a first half of the plurality are disposed in a first of the x-ray beams while a second half of the plurality are disposed in a second of the x-ray beams. Each of the parallel linear sensor arrays is oriented perpendicular to the linear direction of travel. Each of the parallel linear sensor arrays in the first half is matched to a corresponding one of the parallel linear sensor arrays in the second half in terms of an angular position in the first of the x-ray beams and the second of the x-ray beams, respectively.

  16. X-ray computed tomography imaging method which is immune to beam hardening effect

    International Nuclear Information System (INIS)

    Kanno, Ikuo; Uesaka, Akio; Nomiya, Seiichiro; Onabe, Hideaki

    2009-01-01

    For the easy treatment of cancers, early finding of them is an important theme of study. X-ray transmission measurement and computed tomography (CT) are powerful tools for finding cancers. The x-ray CT shows cross sectional view of human body and is able to detect small cancers such as 1 cm in diameter. The CT, however, gives very high dose exposure to human body: some 10 to 1000 times higher dose exposure than the chest radiography. It is not possible to have medical health check using CT frequently, in view of both individual and public accumulated dose exposures. The authors have been working on the reduction of dose exposure in x-ray transmission measurements in case of detecting iodine contrast media, which concentrates in cancers. In our method, energy information of x-rays is employed: in conventional x-ray transmission measurements, x-rays are measured as current and the energy of each x-ray is ignored. The numbers of x-ray events, φ 1 and φ 2 , of which energies are lower and higher than the one of iodine K-edge, respectively, are used for the estimation of iodine thickness in cancers. Moreover, high energy x-rays, which are not sensitive to the absorption by iodine, are cut by a filter made of higher atomic number material than iodine. We call this method filtered x-ray energy subtraction (FIX-ES) method. This FIX-ES method was shown twice as sensitive to iodine than current measurement method. With the choice of filter thickness, minimum dose exposure in FIX-ES is 30% of that when white x-rays are employed. In the study described above, we concentrated on the observation of cancer part. In this study, a cancer phantom in normal tissue is observed by FIX-ES method. The results are compared with the ones obtained by current measurement method. (author)

  17. New methods of X-ray diffraction spectrometry. II

    International Nuclear Information System (INIS)

    Soerum, H.; Bremer, J.

    1980-01-01

    The construction principles for a flexible X-ray spectrometer can be equipped either with a single curved crystal or with two curved crystals are described. A few of the theoretical 4+32 possible working modes are selected for a closer investigation and examples of recorded spectra are given. It is shown in the general single-crystal case that for a wavelength close to a cut-off energy the narrow diffraction cone has an elliptic section, as predicted by the theory. The spectrometer is discussed in terms of intensity, resolution and dispersive power. A comparison with other types of spectrometer is made. (Auth.)

  18. X-ray topographic method of investigation of phase objects

    International Nuclear Information System (INIS)

    Levonyan, L.V.

    2001-01-01

    The intensity distribution of the monochromatized synchrotron radiation transmitting through the phase object and crystal-analyzer in Laue geometry is considered. It is shown that the local angular deviation of the incident radiation caused by the refraction on structural inhomogeneities of the object under investigation is directly transferred to the X-ray topographic image. In the absence of the phase object the latter consists of parallel straight fringes with a slowly decreasing period. The presence of the phase object changes the shape and period of fringes. The influence of the spatial and temporal coherence on the image is discussed. 5 refs

  19. High-speed X-ray phase tomography with Talbot interferometer and fringe scanning method

    International Nuclear Information System (INIS)

    Kibayashi, Shunsuke; Harasse, Sébastien; Yashiro, Wataru; Momose, Atsushi

    2012-01-01

    High-speed X-ray phase tomography based on the Fourier-transform method has been demonstrated with an X-ray Talbot interferometer using white synchrotron radiation. We report the experimental results of high-speed X-ray phase tomography with fringe-scanning method instead of Fourier-transform method to improve spatial resolution without a considerable increase of scan time. To apply fringe-scanning method to high speed tomography, we tested a scan that is a synchronous combination of one-way continuous movements of the sample rotation and the grating displacement. When this scanning method was combined with X-ray phase tomography, we were able to obtain a scan time of 5 s. A comparison of the image quality derived with the conventional approach and with the proposed approach using the fringe-scanning method showed that the latter had better spatial resolution.

  20. An improved in situ method for determining depth distributions of gamma-ray emitting radionuclides

    International Nuclear Information System (INIS)

    Benke, R.R.; Kearfott, K.J.

    2001-01-01

    In situ gamma-ray spectrometry determines the quantities of radionuclides in some medium with a portable detector. The main limitation of in situ gamma-ray spectrometry lies in determining the depth distribution of radionuclides. This limitation is addressed by developing an improved in situ method for determining the depth distributions of gamma-ray emitting radionuclides in large area sources. This paper implements a unique collimator design with conventional radiation detection equipment. Cylindrically symmetric collimators were fabricated to allow only those gamma-rays emitted from a selected range of polar angles (measured off the detector axis) to be detected. Positioned with its axis normal to surface of the media, each collimator enables the detection of gamma-rays emitted from a different range of polar angles and preferential depths. Previous in situ methods require a priori knowledge of the depth distribution shape. However, the absolute method presented in this paper determines the depth distribution as a histogram and does not rely on such assumptions. Other advantages over previous in situ methods are that this method only requires a single gamma-ray emission, provides more detailed depth information, and offers a superior ability for characterizing complex depth distributions. Collimated spectrometer measurements of buried area sources demonstrated the ability of the method to yield accurate depth information. Based on the results of actual measurements, this method increases the potential of in situ gamma-ray spectrometry as an independent characterization tool in situations with unknown radionuclide depth distributions

  1. A method for determination mass absorption coefficient of gamma rays by Compton scattering.

    Science.gov (United States)

    El Abd, A

    2014-12-01

    A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. X-ray studies on electrochemical systems. Synchrotron methods for energy materials

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Artur [Empa. Eidgenoessische Materialpruefungs- und Forschungsanstalt, Duebendorf (Switzerland)

    2017-07-01

    This book is your graduate level entrance into battery, fuel cell and solar cell research at synchrotron X-ray sources. Materials scientists find numerous examples for the combination of electrochemical experiments with simple and with highly complex X-ray scattering and spectroscopy methods. Physicists and chemists can link applied electrochemistry with fundamental concepts of condensed matter physics, physical chemistry and surface science.

  3. Improvements in γ-ray reconstruction with positive sensitive Ge detectors using the backtracking method

    International Nuclear Information System (INIS)

    Milechina, L.; Cederwall, B.

    2003-01-01

    Gamma-ray tracking, a new detection technique for nuclear spectroscopy, requires efficient algorithms for reconstructing the interaction paths of multiple γ rays in a detector volume. In the present work, we discuss the effect of the atomic electron momentum distribution in Ge as well as employment of different types of figure-of-merit within the context of the so called backtracking method

  4. ASSESSMENT OF RESTORATION METHODS OF X-RAY IMAGES WITH EMPHASIS ON MEDICAL PHOTOGRAMMETRIC USAGE

    Directory of Open Access Journals (Sweden)

    S. Hosseinian

    2016-06-01

    Full Text Available Nowadays, various medical X-ray imaging methods such as digital radiography, computed tomography and fluoroscopy are used as important tools in diagnostic and operative processes especially in the computer and robotic assisted surgeries. The procedures of extracting information from these images require appropriate deblurring and denoising processes on the pre- and intra-operative images in order to obtain more accurate information. This issue becomes more considerable when the X-ray images are planned to be employed in the photogrammetric processes for 3D reconstruction from multi-view X-ray images since, accurate data should be extracted from images for 3D modelling and the quality of X-ray images affects directly on the results of the algorithms. For restoration of X-ray images, it is essential to consider the nature and characteristics of these kinds of images. X-ray images exhibit severe quantum noise due to limited X-ray photons involved. The assumptions of Gaussian modelling are not appropriate for photon-limited images such as X-ray images, because of the nature of signal-dependant quantum noise. These images are generally modelled by Poisson distribution which is the most common model for low-intensity imaging. In this paper, existing methods are evaluated. For this purpose, after demonstrating the properties of medical X-ray images, the more efficient and recommended methods for restoration of X-ray images would be described and assessed. After explaining these approaches, they are implemented on samples from different kinds of X-ray images. By considering the results, it is concluded that using PURE-LET, provides more effective and efficient denoising than other examined methods in this research.

  5. DNA barcoding unveils skate (Chondrichthyes: Rajidae) species diversity in 'ray' products sold across Ireland and the UK.

    Science.gov (United States)

    Griffiths, Andrew Mark; Miller, Dana D; Egan, Aaron; Fox, Jennifer; Greenfield, Adam; Mariani, Stefano

    2013-01-01

    Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba). Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of "skate" or "ray". The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., "winged") and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a single retailer

  6. Methods for reduction of scattered x-ray in measuring MTF with the square chart

    International Nuclear Information System (INIS)

    Hatagawa, Masakatsu; Yoshida, Rie

    1982-01-01

    A square wave chart has been used to measure the MTF of a screen-film system. The problem is that the scattered X-ray from the chart may give rise to measurement errors. In this paper, the authors proposed two methods to reduce the scattered X-ray: the first method is the use of a Pb mask and second is to provide for an air gap between the chart and the screen-film system. In these methods, the scattered X-ray from the chart was reduced. MTFs were measured by both of the new methods and the conventional method, and MTF values of the new methods were in good agreement while that of the conventional method was not. It was concluded that these new methods are able to reduce errors in the measurement of MTF. (author)

  7. Determination of chlorine in coal by X-ray fluorescence spectrometry method

    Energy Technology Data Exchange (ETDEWEB)

    Marek, S.; Bojarska, K. [Central Mining Institute, Katowice (Poland). Dept. of Environmental Monitoring

    1997-12-31

    Determination of chlorine contents in coal is essential for both environmental protection and its technological use. The existing method of chlorine determination in coal are titration methods which have considerable errors particularly in the low concentration range. The elaborated method with the use of X-ray fluorescence spectrometry in a comparison to the other methods is much faster and has better precision and accuracy. The principle of the method lies in the measurement of X-ray fluorescence radiation intensity which is emitted by chlorine in a sample and its comparison with standards. The calibration of the elaborated XRF method is based on natural coals having various concentrations of chlorine within the whole range of its occurrence in Polish coals. Concentrations for the calibration purpose were obtained by the determination of chlorine contents in selected coals by atomic absorption spectrometry method. The procedure of sample preparation for direct X-ray measurements, instrumental measuring conditions and the way of calibration curve preparation are described in the paper. All X-ray measurements were done with a Phillips sequential X-ray fluorescence spectrometer. A double anode Cr-Au X-ray tube with maximum power 3000 MW was used as the excitation source. 5 figs., 4 tabs.

  8. Quantitative method of X-ray diffraction phase analysis of building materials

    International Nuclear Information System (INIS)

    Czuba, J.; Dziedzic, A.

    1978-01-01

    Quantitative method of X-ray diffraction phase analysis of building materials, with use of internal standard, has been presented. The errors committed by determining the content of particular phases have been also given. (author)

  9. Use of the maximum entropy method in X-ray astronomy

    International Nuclear Information System (INIS)

    Willingale, R.

    1981-01-01

    An algorithm used to apply the maximum entropy method in X-ray astronomy is described. It is easy to programme on a digital computer and fast enough to allow processing of two-dimensional images. The method gives good noise suppression without loss of instrumental resolution and has been successfully applied to several data analysis problems in X-ray astronomy. The restoration of a high-resolution image from the Einstein Observatory demonstrates the use of the algorithm. (author)

  10. X-ray methods for the chemical characterization of atmospheric aerosols

    International Nuclear Information System (INIS)

    Jaklevic, J.M.; Thompson, A.C.

    1981-05-01

    The development and use of several x-ray methods for the chemical characterization of atmospherical aerosol particulate samples are described. These methods are based on the emission, absorption, and scattering of x-ray photons with emphasis on the optimization for the non-destructive analysis of dilute specimens. Techniques discussed include photon induced energy dispersive x-ray fluorescence, extended x-ray absorption fine structure spectroscopy using synchrotron radiation and high-rate x-ray powder diffractometry using a position-sensitive gas proportional counter. These x-ray analysis methods were applied to the measurement of the chemical compositions of size-segregated aerosol particulate samples obtained with dichotomous samplers. The advantages of the various methods for use in such measurements are described and results are presented. In many cases, the complementary nature of the analytical information obtained from the various measurements is an important factor in the characterization of the sample. For example, the multiple elemental analyses obtained from x-ray fluorescence can be used as a cross check on the major compounds observed by powder diffraction

  11. Development of Extended Ray-tracing method including diffraction, polarization and wave decay effects

    Science.gov (United States)

    Yanagihara, Kota; Kubo, Shin; Dodin, Ilya; Nakamura, Hiroaki; Tsujimura, Toru

    2017-10-01

    Geometrical Optics Ray-tracing is a reasonable numerical analytic approach for describing the Electron Cyclotron resonance Wave (ECW) in slowly varying spatially inhomogeneous plasma. It is well known that the result with this conventional method is adequate in most cases. However, in the case of Helical fusion plasma which has complicated magnetic structure, strong magnetic shear with a large scale length of density can cause a mode coupling of waves outside the last closed flux surface, and complicated absorption structure requires a strong focused wave for ECH. Since conventional Ray Equations to describe ECW do not have any terms to describe the diffraction, polarization and wave decay effects, we can not describe accurately a mode coupling of waves, strong focus waves, behavior of waves in inhomogeneous absorption region and so on. For fundamental solution of these problems, we consider the extension of the Ray-tracing method. Specific process is planned as follows. First, calculate the reference ray by conventional method, and define the local ray-base coordinate system along the reference ray. Then, calculate the evolution of the distributions of amplitude and phase on ray-base coordinate step by step. The progress of our extended method will be presented.

  12. A novel method for quantitative geosteering using azimuthal gamma-ray logging.

    Science.gov (United States)

    Yuan, Chao; Zhou, Cancan; Zhang, Feng; Hu, Song; Li, Chaoliu

    2015-02-01

    A novel method for quantitative geosteering by using azimuthal gamma-ray logging is proposed. Real-time up and bottom gamma-ray logs when a logging tool travels through a boundary surface with different relative dip angles are simulated with the Monte Carlo method. Study results show that response points of up and bottom gamma-ray logs when the logging tool moves towards a highly radioactive formation can be used to predict the relative dip angle, and then the distance from the drilling bit to the boundary surface is calculated. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Method of evaluation of structural (screen) and quantum graininess of X-ray pictures

    Energy Technology Data Exchange (ETDEWEB)

    Gurvich, A M; Shamanov, A A; Erofeeva, N D [Nauchno-Issledovatel' skij Inst. Rentgenologii i Radiologii, Moscow (USSR)

    1979-03-01

    Proposed is a method for quantitative determination of graininess of X-ray pictures (gamma-ray images), the graininess being conditioned by the structure of amplifying screens and quantum fluctuations. The method is based on the determination of threshold brightness at which the picture graininess becomes obvious. It is shown that at low effective quantum energy (Esub(eff.) <= 50 keV) the graininess observed is for the most part structural (screen). Its growth is connected with quantum fluctuations when increasing Esub(eff.) up to 150 keV and using screens with high output values of X-ray luminescence and the coefficient of spectral accordance to the film.

  14. High resolution x-ray CMT: Reconstruction methods

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.K.

    1997-02-01

    This paper qualitatively discusses the primary characteristics of methods for reconstructing tomographic images from a set of projections. These reconstruction methods can be categorized as either {open_quotes}analytic{close_quotes} or {open_quotes}iterative{close_quotes} techniques. Analytic algorithms are derived from the formal inversion of equations describing the imaging process, while iterative algorithms incorporate a model of the imaging process and provide a mechanism to iteratively improve image estimates. Analytic reconstruction algorithms are typically computationally more efficient than iterative methods; however, analytic algorithms are available for a relatively limited set of imaging geometries and situations. Thus, the framework of iterative reconstruction methods is better suited for high accuracy, tomographic reconstruction codes.

  15. Role of X-ray examination methods in the diagnosis of endophytic stomach carcinomas

    International Nuclear Information System (INIS)

    Gorshkov, A.N.; Akberov, R.F.

    1998-01-01

    Results of studying potentialities of radiographic methods in the diagnosis of stomach endophytic neoplasms (130 cases) are presented. All of patients were exposed to complex radiographic-endoscopic studies of stomach. X-ray computerized tomography is used as an additional method. It is shown that the complex approach to the diagnosis of endophytic neoplasms of stomach is necessary. Radiographic method is proposed to be used as an initial examination method. Endoscopic method with multiple biopsy is also used. X-ray computerized tomography is used for certain anatomic stomach section at the final stage [ru

  16. Studies of oxide-based thin-layered heterostructures by X-ray scattering methods

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France)]. E-mail: olivier.durand@thalesgroup.com; Rogers, D. [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Universite de Technologie de Troyes, 10-12 rue Marie Curie, 10010 (France); Teherani, F. Hosseini [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Andrieux, M. [LEMHE, ICMMOCNRS-UMR 8182, Universite d' Orsay, Batiment 410, 91410 Orsay (France); Modreanu, M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)

    2007-06-04

    Some X-ray scattering methods (X-ray reflectometry and Diffractometry) dedicated to the study of thin-layered heterostructures are presented with a particular focus, for practical purposes, on the description of fast, accurate and robust techniques. The use of X-ray scattering metrology as a routinely working non-destructive testing method, particularly by using procedures simplifying the data-evaluation, is emphasized. The model-independent Fourier-inversion method applied to a reflectivity curve allows a fast determination of the individual layer thicknesses. We demonstrate the capability of this method by reporting X-ray reflectometry study on multilayered oxide structures, even when the number of the layers constitutive of the stack is not known a-priori. Fast Fourier transform-based procedure has also been employed successfully on high resolution X-ray diffraction profiles. A study of the reliability of the integral-breadth methods in diffraction line-broadening analysis applied to thin layers, in order to determine coherent domain sizes, is also reported. Examples from studies of oxides-based thin-layers heterostructures will illustrate these methods. In particular, X-ray scattering studies performed on high-k HfO{sub 2} and SrZrO{sub 3} thin-layers, a (GaAs/AlOx) waveguide, and a ZnO thin-layer are reported.

  17. Handbook on simultaneous x-ray and γ-ray ion beam methods for fine particle analysis

    International Nuclear Information System (INIS)

    Cohen, D.D.

    2000-01-01

    Sampling, measurement, characterisation and source appointment of fine atmospheric particles has become increasingly important in recent times. This is due in part to the realisation that the fine particle pollution caused by anthropogenic activities plays a key role in certain aspects of human health, pollution transport and global climate change. This publication discusses accelerator based ion beam analysis (IBA) methods of particle induced X-ray emission (PIXE) and particle induced γ-ray emission (PIGE) as applied to aerosol analysis. These techniques are sensitive, multielemental, mainly non-destructive, require no sample preparation, have short analysis times and can be used to analyse hundreds of filter samples a day in batch processing with minimum operator interaction. The aspects discussed in the publication include: the basics of the techniques; spectrum analysis; system calibration and blank subtraction; quantification; sensitivity; measurement errors

  18. An Energy Conservative Ray-Tracing Method With a Time Interpolation of the Force Field

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-10

    A new algorithm that constructs a continuous force field interpolated in time is proposed for resolving existing difficulties in numerical methods for ray-tracing. This new method has improved accuracy, but with the same degree of algebraic complexity compared to Kaisers method.

  19. Computed tomography of x-ray index of refraction using the diffraction enhanced imaging method

    International Nuclear Information System (INIS)

    Dilmanian, F.A.; Ren, B.; Wu, X.Y.; Orion, I.; Zhong, Z.; Thomlinson, W.C.; Chapman, L.D.

    2000-01-01

    Diffraction enhanced imaging (DEI) is a new, synchrotron-based, x-ray radiography method that uses monochromatic, fan-shaped beams, with an analyser crystal positioned between the subject and the detector. The analyser allows the detection of only those x-rays transmitted by the subject that fall into the acceptance angle (central part of the rocking curve) of the monochromator/analyser system. As shown by Chapman et al , in addition to the x-ray attenuation, the method provides information on the out-of-plane angular deviation of x-rays. New images result in which the image contrast depends on the x-ray index of refraction and on the yield of small-angle scattering, respectively. We implemented DEI in the tomography mode at the National Synchrotron Light Source using 22 keV x-rays, and imaged a cylindrical acrylic phantom that included oil-filled, slanted channels. The resulting 'refraction CT image' shows the pure image of the out-of-plane gradient of the x-ray index of refraction. No image artefacts were present, indicating that the CT projection data were a consistent set. The 'refraction CT image' signal is linear with the gradient of the refractive index, and its value is equal to that expected. The method, at the energy used or higher, has the potential for use in clinical radiography and in industry. (author)

  20. Research of x-ray automatic image mosaic method

    Science.gov (United States)

    Liu, Bin; Chen, Shunan; Guo, Lianpeng; Xu, Wanpeng

    2013-10-01

    Image mosaic has widely applications value in the fields of medical image analysis, and it is a technology that carries on the spatial matching to a series of image which are overlapped with each other, and finally builds a seamless and high quality image which has high resolution and big eyeshot. In this paper, the method of grayscale cutting pseudo-color enhancement was firstly used to complete the mapping transformation from gray to the pseudo-color, and to extract SIFT features from the images. And then by making use of a similar measure of NCC (normalized cross correlation - Normalized cross-correlation), the method of RANSAC (Random Sample Consensus) was used to exclude the pseudofeature points right in order to complete the exact match of feature points. Finally, seamless mosaic and color fusion were completed by using wavelet multi-decomposition. The experiment shows that the method we used can effectively improve the precision and automation of the medical image mosaic, and provide an effective technical approach for automatic medical image mosaic.

  1. ACCELERATION RENDERING METHOD ON RAY TRACING WITH ANGLE COMPARISON AND DISTANCE COMPARISON

    Directory of Open Access Journals (Sweden)

    Liliana liliana

    2007-01-01

    Full Text Available In computer graphics applications, to produce realistic images, a method that is often used is ray tracing. Ray tracing does not only model local illumination but also global illumination. Local illumination count ambient, diffuse and specular effects only, but global illumination also count mirroring and transparency. Local illumination count effects from the lamp(s but global illumination count effects from other object(s too. Objects that are usually modeled are primitive objects and mesh objects. The advantage of mesh modeling is various, interesting and real-like shape. Mesh contains many primitive objects like triangle or square (rare. A problem in mesh object modeling is long rendering time. It is because every ray must be checked with a lot of triangle of the mesh. Added by ray from other objects checking, the number of ray that traced will increase. It causes the increasing of rendering time. To solve this problem, in this research, new methods are developed to make the rendering process of mesh object faster. The new methods are angle comparison and distance comparison. These methods are used to reduce the number of ray checking. The rays predicted will not intersect with the mesh, are not checked weather the ray intersects the mesh. With angle comparison, if using small angle to compare, the rendering process will be fast. This method has disadvantage, if the shape of each triangle is big, some triangles will be corrupted. If the angle to compare is bigger, mesh corruption can be avoided but the rendering time will be longer than without comparison. With distance comparison, the rendering time is less than without comparison, and no triangle will be corrupted.

  2. Further results for crack-edge mappings by ray methods

    International Nuclear Information System (INIS)

    Norris, A.N.; Achenbach, J.D.; Ahlberg, L.; Tittman, B.R.

    1984-01-01

    This chapter discusses further extensions of the local edge mapping method to the pulse-echo case and to configurations of water-immersed specimens and transducers. Crack edges are mapped by the use of arrival times of edge-diffracted signals. Topics considered include local edge mapping in a homogeneous medium, local edge mapping algorithms, local edge mapping through an interface, and edge mapping through an interface using synthetic data. Local edge mapping is iterative, with two or three iterations required for convergence

  3. A new method for imaging nuclear threats using cosmic ray muons

    International Nuclear Information System (INIS)

    Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Tim; Aberle, Derek; Green, J. Andrew; McDuff, George G.; Lukić, Zarija; Milner, Edward C.

    2013-01-01

    Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

  4. A new method for imaging nuclear threats using cosmic ray muons

    Science.gov (United States)

    Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Tim; Aberle, Derek; Green, J. Andrew; McDuff, George G.; Lukić, Zarija; Milner, Edward C.

    2013-08-01

    Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

  5. Method for detecting binding events using micro-X-ray fluorescence spectrometry

    Science.gov (United States)

    Warner, Benjamin P.; Havrilla, George J.; Mann, Grace

    2010-12-28

    Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

  6. A new method for imaging nuclear threats using cosmic ray muons

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Tim [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Aberle, Derek; Green, J. Andrew; McDuff, George G. [National Security Technologies, Los Alamos, NM 87544 (United States); Lukić, Zarija [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Milner, Edward C. [Southern Methodist University, Dallas, TX 75205 (United States)

    2013-08-15

    Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

  7. A new method for imaging nuclear threats using cosmic ray muons

    Directory of Open Access Journals (Sweden)

    C. L. Morris

    2013-08-01

    Full Text Available Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for reconstruction. Here we demonstrate a new method for obtaining improved position resolution and statistical precision for objects with spherical symmetry.

  8. On the evaluation of X-ray diffraction experiments by the regularization method

    Energy Technology Data Exchange (ETDEWEB)

    Trubin, V.A.; Szasz, A. (Lab. of Surface and Interface Physics, Eoetvoes Univ., Budapest (Hungary))

    1991-05-16

    The characteristic property of diffractometers as the presence of occasional and systematic errors in measured patterns requires such an evaluation which is as informative as possible. This circumstance gives rise to the problem of optimal planning of the experiment. The X-ray diffraction optimization problem with application of the regularization method is studied. The proposal permits to determine more accurately the unknown true characteristics of the X-ray diffraction experiment. (orig.).

  9. On the evaluation of X-ray diffraction experiments by the regularization method

    International Nuclear Information System (INIS)

    Trubin, V.A.; Szasz, A.

    1991-01-01

    The characteristic property of diffractometers as the presence of occasional and systematic errors in measured patterns requires such an evaluation which is as informative as possible. This circumstance gives rise to the problem of optimal planning of the experiment. The X-ray diffraction optimization problem with application of the regularization method is studied. The proposal permits to determine more accurately the unknown true characteristics of the X-ray diffraction experiment. (orig.)

  10. Calibration method of the pulsed X-ray relative sensitivity for ST401 plastic scintillators

    International Nuclear Information System (INIS)

    Xie Hongwei; Song Guzhou; Wang Kuilu

    2011-01-01

    The relative sensitivity calibration method of the pulsed X-ray in ST401 plastic scintillator is presented. Experimental relative sensitivity calibrations of the plastic scintillators of different thicknesses from 1 mm to 50 mm are accomplished on the 'Chenguang' pulsed X-ray source and a Co radioactive source, The uncertainty of the calibration data is evaluated, which can be treated as the experimental evidence for the relative sensitivity conversion of ST401 plastic scintillator. (authors)

  11. A method for determination mass absorption coefficient of gamma rays by Compton scattering

    International Nuclear Information System (INIS)

    El Abd, A.

    2014-01-01

    A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. - Highlights: • Compton scattering of γ−rays was used for determining mass absorption coefficient. • Scattered intensities were determined by the MCSHAPE software. • Mass absorption coefficients were determined for some compounds, mixtures and alloys. • Mass absorption coefficients were calculated by Winxcom software. • Good agreements were found between determined and calculated results

  12. Smoothed Particle Inference: A Kilo-Parametric Method for X-ray Galaxy Cluster Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, John R.; Marshall, P.J.; /KIPAC, Menlo Park; Andersson, K.; /Stockholm U. /SLAC

    2005-08-05

    We propose an ambitious new method that models the intracluster medium in clusters of galaxies as a set of X-ray emitting smoothed particles of plasma. Each smoothed particle is described by a handful of parameters including temperature, location, size, and elemental abundances. Hundreds to thousands of these particles are used to construct a model cluster of galaxies, with the appropriate complexity estimated from the data quality. This model is then compared iteratively with X-ray data in the form of adaptively binned photon lists via a two-sample likelihood statistic and iterated via Markov Chain Monte Carlo. The complex cluster model is propagated through the X-ray instrument response using direct sampling Monte Carlo methods. Using this approach the method can reproduce many of the features observed in the X-ray emission in a less assumption-dependent way that traditional analyses, and it allows for a more detailed characterization of the density, temperature, and metal abundance structure of clusters. Multi-instrument X-ray analyses and simultaneous X-ray, Sunyaev-Zeldovich (SZ), and lensing analyses are a straight-forward extension of this methodology. Significant challenges still exist in understanding the degeneracy in these models and the statistical noise induced by the complexity of the models.

  13. Nuclear Enhanced X-ray Maximum Entropy Method Used to Analyze Local Distortions in Simple Structures

    DEFF Research Database (Denmark)

    Christensen, Sebastian; Bindzus, Niels; Christensen, Mogens

    We introduce a novel method for reconstructing pseudo nuclear density distributions (NDDs): Nuclear Enhanced X-ray Maximum Entropy Method (NEXMEM). NEXMEM offers an alternative route to experimental NDDs, exploiting the superior quality of synchrotron X-ray data compared to neutron data. The method...... proposed to result from anharmonic phonon scattering or from local fluctuating dipoles on the Pb site.[1,2] No macroscopic symmetry change are associated with these effects, rendering them invisible to conventional crystallographic techniques. For this reason PbX was until recently believed to adopt...

  14. The unfolding of NaI(Tl) γ-ray spectrum based on maximum likelihood method

    International Nuclear Information System (INIS)

    Zhang Qingxian; Ge Liangquan; Gu Yi; Zeng Guoqiang; Lin Yanchang; Wang Guangxi

    2011-01-01

    NaI(Tl) detectors, having a good detection efficiency, are used to detect gamma rays in field surveys. But the poor energy resolution hinders their applications, despite the use of traditional methods to resolve the overlapped gamma-ray peaks. In this paper, the maximum likelihood (ML) solution is used to resolve the spectrum. The ML method,which is capable of decomposing the peaks in energy difference of over 2/3 FWHM, is applied to scale NaI(Tl) the spectrometer. The result shows that the net area is in proportion to the content of isotopes and the precision of scaling is better than the stripping ration method. (authors)

  15. Gamma ray energy loss spectra simulation in NaI detectors with the Monte Carlo method

    International Nuclear Information System (INIS)

    Vieira, W.J.

    1982-01-01

    With the aim of studying and applying the Monte Carlo method, a computer code was developed to calculate the pulse height spectra and detector efficiencies for gamma rays incident on NaI (Tl) crystals. The basic detector processes in NaI (Tl) detectors are given together with an outline of Monte Carlo methods and a general review of relevant published works. A detailed description of the application of Monte Carlo methods to ν-ray detection in NaI (Tl) detectors is given. Comparisons are made with published, calculated and experimental, data. (Author) [pt

  16. A model independent method to deconvolve hard X-ray spectra

    International Nuclear Information System (INIS)

    Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C.

    1984-01-01

    A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented. (orig.)

  17. X-ray and nuclear methods for comparative analysis of environmental samples

    International Nuclear Information System (INIS)

    Kudryashov, V.I.; Gundorina, S.F.; Frontas'eva, M.V.; Saidmuradov, Zh.

    1988-01-01

    X-ray and instrumental neutron activation methods, and in some cases methods of photon activation (X-ray spectral analysis with proton activation and analysis on the basis of (p, n) reaction) were used to obtain elementary content of different water samples. The possibility of getting space-time dependences of trace elementary concentrations in water (and under certain conditions in atmosphere) is shown. These data are to be used at a complex investigation of sanitary norms of water systems. The advantages of abovementined methods are discussed for obtaining different elementary content in water in different ways

  18. Computerized method for X-ray angular distribution simulation in radiological systems

    International Nuclear Information System (INIS)

    Marques, Marcio A.; Oliveira, Henrique J.Q. de; Frere, Annie F.; Schiabel, Homero; Marques, Paulo M.A.

    1996-01-01

    A method to simulate the changes in X-ray angular distribution (the Heel effect) for radiologic imaging systems is presented. This simulation method is described as to predict images for any exposure technique considering that the distribution is the cause of the intensity variation along the radiation field

  19. Precision evaluation of pressed pastille preparation different methods for X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Lima, Raquel Franco de Souza; Melo Junior, Germano; Sa, Jaziel Martins

    1997-01-01

    This work relates the comparison between the results obtained with the two different methods of preparing pressed pastilles from the crushed sample. In this study, the reproductivity is evaluated, aiming to define the method that furnishes a better analytic precision. These analyses were realized with a X-ray fluorescence spectrometer at the Geology Department of the Federal University of Rio Grande do Norte

  20. Pseudo forward ray-tracing: A new method for surface validation in cornea topography

    NARCIS (Netherlands)

    Sicam, V.; Snellenburg, J.J.; van der Heijde, R.G.; van Stokkum, I.H.M.

    2007-01-01

    PURPOSE. A pseudo forward ray-tracing (PFRT) algorithm is developed to evaluate surface reconstruction in corneal topography. The method can be applied to topographers where one-to-one correspondence between mire and image points can be established. METHODS. The PFRT algorithm was applied on a

  1. Method for x-ray determination of three axial stresses of general orientation

    Energy Technology Data Exchange (ETDEWEB)

    Doelle, H; Hauk, V [Technische Hochschule Aachen (Germany, F.R.). Inst. fuer Werkstoffkunde; Juehe, H H; Krause, H [Technische Hochschule Aachen (Germany, F.R.). Lehrgebiet Abnutzung der Werkstoffe

    1976-11-01

    The authors describe a method of detecting three-dimensional self-stress/self-strain systems by means of X-ray measurements of the distances between the lattice planes in three directions of the sample surface. The method is illustrated by a study of a sample from a type of an electric railcar which had been deformed mainly by tangential forces.

  2. Quantitative phase analysis of uranium carbide from x-ray diffraction data using the Rietveld method

    International Nuclear Information System (INIS)

    Singh Mudher, K.D.; Krishnan, K.

    2003-01-01

    Quantitative phase analysis of a uranium carbide sample was carried out from the x-ray diffraction data by Rietveld profile fitting method. The method does not require the addition of any reference material. The percentage of UC, UC 2 and UO 2 phases in the sample were determined. (author)

  3. The method of quantitative X-ray microanalysis of fine inclusions in copper

    International Nuclear Information System (INIS)

    Morawiec, H.; Kubica, L.; Piszczek, J.

    1978-01-01

    The method of correction for the matrix effect in quantitative x-ray microanalysis was presented. The application of the method was discussed on the example of quantitative analysis of fine inclusions of Cu 2 S and Cu 2 O in copper. (author)

  4. Fast, versatile x-ray fluorescence method for measuring tin in impregnated wood

    DEFF Research Database (Denmark)

    Drabæk, I.; Christensen, Leif Højslet

    1985-01-01

    The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples...

  5. Methods for the reconstruction of large scale anisotropies of the cosmic ray flux

    Energy Technology Data Exchange (ETDEWEB)

    Over, Sven

    2010-01-15

    In cosmic ray experiments the arrival directions, among other properties, of cosmic ray particles from detected air shower events are reconstructed. The question of uniformity in the distribution of arrival directions is of large importance for models that try to explain cosmic radiation. In this thesis, methods for the reconstruction of parameters of a dipole-like flux distribution of cosmic rays from a set of recorded air shower events are studied. Different methods are presented and examined by means of detailed Monte Carlo simulations. Particular focus is put on the implications of spurious experimental effects. Modifications of existing methods and new methods are proposed. The main goal of this thesis is the development of the horizontal Rayleigh analysis method. Unlike other methods, this method is based on the analysis of local viewing directions instead of global sidereal directions. As a result, the symmetries of the experimental setup can be better utilised. The calculation of the sky coverage (exposure function) is not necessary in this analysis. The performance of the method is tested by means of further Monte Carlo simulations. The new method performs similarly good or only marginally worse than established methods in case of ideal measurement conditions. However, the simulation of certain experimental effects can cause substantial misestimations of the dipole parameters by the established methods, whereas the new method produces no systematic deviations. The invulnerability to certain effects offers additional advantages, as certain data selection cuts become dispensable. (orig.)

  6. Integration of the ATHENA mirror modules: development of indirect and x-ray direct AIT methods

    Science.gov (United States)

    Vernani, Dervis; Blum, Steffen; Seure, Thibault; Bavdaz, Marcos; Wille, Eric; Schaeffer, Uwe; Lièvre, Nicolas; Nazeeruddin, Adeeb; Barrière, Nicolas M.; Collon, Maximilien J.; Cibik, Levent; Krumrey, Michael; Müller, Peter; Burwitz, Vadim

    2017-08-01

    Within the ATHENA optics technology plan, activities are on-going for demonstrating the feasibility of the mirror module Assembly Integration and Testing (AIT). Each mirror module has to be accurately attached to the mirror structure by means of three isostatic mounts ensuring minimal distortion under environmental loads. This work reports on the status of one of the two parallel activities initiated by ESA to address this demanding task. In this study awarded to the industrial consortium, the integration relies on opto-mechanical metrology and direct X-ray alignment. For the first or "indirect" method the X-ray alignment results are accurately referenced, by means of a laser tracking system, to optical fiducial targets mounted on the mirror modules and finally linked to the mirror structure coordinate system. With the second or "direct" method the alignment is monitored in the X-ray domain, providing figures of merit directly comparable to the final performance. The integration being designed and here presented, foresees combining the indirect method to the X-ray direct method. The characterization of the single mirror modules is planned at PTB's X-ray Parallel Beam Facility (XPBF 2.0) at BESSY II, and the integration and testing campaign at Panter. It is foreseen to integrate and test a demonstrator with two real mirror modules manufactured by cosine.

  7. An efficient ray tracing method for propagation prediction along a mobile route in urban environments

    Science.gov (United States)

    Hussain, S.; Brennan, C.

    2017-07-01

    This paper presents an efficient ray tracing algorithm for propagation prediction in urban environments. The work presented in this paper builds upon previous work in which the maximum coverage area where rays can propagate after interaction with a wall or vertical edge is described by a lit polygon. The shadow regions formed by buildings within the lit polygon are described by shadow polygons. In this paper, the lit polygons of images are mapped to a coarse grid superimposed over the coverage area. This mapping reduces the active image tree significantly for a given receiver point to accelerate the ray finding process. The algorithm also presents an efficient method of quickly determining the valid ray segments for a mobile receiver moving along a linear trajectory. The validation results show considerable computation time reduction with good agreement between the simulated and measured data for propagation prediction in large urban environments.

  8. General beam position controlling method for 3D optical systems based on the method of solving ray matrix equations

    Science.gov (United States)

    Chen, Meixiong; Yuan, Jie; Long, Xingwu; Kang, Zhenglong; Wang, Zhiguo; Li, Yingying

    2013-12-01

    A general beam position controlling method for 3D optical systems based on the method of solving ray matrix equations has been proposed in this paper. As a typical 3D optical system, nonplanar ring resonator of Zero-Lock Laser Gyroscopes has been chosen as an example to show its application. The total mismatching error induced by Faraday-wedge in nonplanar ring resonator has been defined and eliminated quite accurately with the error less than 1 μm. Compared with the method proposed in Ref. [14], the precision of the beam position controlling has been improved by two orders of magnitude. The novel method can be used to implement automatic beam position controlling in 3D optical systems with servo circuit. All those results have been confirmed by related alignment experiments. The results in this paper are important for beam controlling, ray tracing, cavity design and alignment in 3D optical systems.

  9. A practical material decomposition method for x-ray dual spectral computed tomography.

    Science.gov (United States)

    Hu, Jingjing; Zhao, Xing

    2016-03-17

    X-ray dual spectral CT (DSCT) scans the measured object with two different x-ray spectra, and the acquired rawdata can be used to perform the material decomposition of the object. Direct calibration methods allow a faster material decomposition for DSCT and can be separated in two groups: image-based and rawdata-based. The image-based method is an approximative method, and beam hardening artifacts remain in the resulting material-selective images. The rawdata-based method generally obtains better image quality than the image-based method, but this method requires geometrically consistent rawdata. However, today's clinical dual energy CT scanners usually measure different rays for different energy spectra and acquire geometrically inconsistent rawdata sets, and thus cannot meet the requirement. This paper proposes a practical material decomposition method to perform rawdata-based material decomposition in the case of inconsistent measurement. This method first yields the desired consistent rawdata sets from the measured inconsistent rawdata sets, and then employs rawdata-based technique to perform material decomposition and reconstruct material-selective images. The proposed method was evaluated by use of simulated FORBILD thorax phantom rawdata and dental CT rawdata, and simulation results indicate that this method can produce highly quantitative DSCT images in the case of inconsistent DSCT measurements.

  10. A simple source preparation method for alpha-ray spectrometry of volcanic rock sample

    International Nuclear Information System (INIS)

    Takahashi, Masaomi; Kurihara, Yuichi; Sato, Jun

    2006-01-01

    A simple source preparation method was developed for the alpha-ray spectrometry to determine U and Th in volcanic rockes. Isolation of U and Th from volcanic rocks was made by use of UTEVA-Spec. resin, extraction chromatograph material. U and Th were extracted by TTA-benzene solution and organic phase was evaporated drop by drop on a hot stainless steel planchet to dryness. This method was found to be effective for the preparation of sources for alpha-ray spectrometry. (author)

  11. A new method of alpha ray measurement using a Quadrupole Mass Spectrometer

    International Nuclear Information System (INIS)

    Iwata, Y.; Inoue, Y.; Minowa, M.

    2007-01-01

    We propose a new method of alpha (α)-ray measurement that detects helium atoms with a Quadrupole Mass Spectrometer (QMS). A demonstration is undertaken with a plastic-covered 241 Am α-emitting source to detect α-rays stopped in the capsule. We successfully detect helium atoms that diffuse out of the capsule by accumulating them for 1-20h in a closed chamber. The detected amount is found to be proportional to the accumulation time. Our method is applicable to probe α-emitting radioactivity in bulk material

  12. Neutron transport study based on assembly modular ray tracing MOC method

    International Nuclear Information System (INIS)

    Tian Chao; Zheng Youqi; Li Yunzhao; Li Shuo; Chai Xiaoming

    2015-01-01

    It is difficulty for the MOC method based on Cell Modular Ray Tracing to deal with the irregular geometry such as the water gap between the PWR lattices. Hence, the neutron transport code NECP-Medlar based on Assembly Modular Ray Tracing is developed. CMFD method is used to accelerate the transport calculation. The numerical results of the 2D C5G7 benchmark and typical PWR lattice prove that NECP-Medlar has an excellent performance in terms of accuracy and efficiency. Besides, NECP-Medlar can describe clearly the flux distribution of the lattice with water gap. (authors)

  13. Visualization of boron in molybdenum by α-rays track etching method and tritium autoradiography

    International Nuclear Information System (INIS)

    Saito, Hideo; Morita, Fumio

    2003-01-01

    Molybdenum alloys addicted with < 0.02 ppm B to 160 ppm B were analyzed by α-rays track etching (ATE) method irradiated by thermal neutron for 12 hours using atomic reactor of Rikkyo University and Japan atomic reactor of JRR-4. It was found that boron was segregated along grain boundaries and in the matrix. We analyzed boron distribution in the vicinity of the triple junctions at grain boundaries and in the matrix by the statistical frequency of α-rays tracks. Also we studied tritium autoradiography by cathodic charging method. Visualization of boron distribution was confirmed along the grain boundary which seemed to be effective trapping sites of hydrogen. (author)

  14. Method for calculating required shielding in medical x-ray rooms

    International Nuclear Information System (INIS)

    Karppinen, J.

    1997-10-01

    The new annual radiation dose limits - 20 mSv (previously 50 mSv) for radiation workers and 1 mSv (previously 5 mSv) for other persons - implies that the adequacy of existing radiation shielding must be re-evaluated. In principle, one could assume that the thicknesses of old radiation shields should be increased by about one or two half-value layers in order to comply with the new dose limits. However, the assumptions made in the earlier shielding calculations are highly conservative; the required shielding was often determined by applying the maximum high-voltage of the x-ray tube for the whole workload. A more realistic calculation shows that increased shielding is typically not necessary if more practical x-ray tube voltages are used in the evaluation. We have developed a PC-based calculation method for calculating the x-ray shielding which is more realistic than the highly conservative method formerly used. The method may be used to evaluate an existing shield for compliance with new regulations. As examples of these calculations, typical x-ray rooms are considered. The lead and concrete thickness requirements as a function of x-ray tube voltage and workload are also given in tables. (author)

  15. A new method to make gamma-ray self-absorption correction

    International Nuclear Information System (INIS)

    Tian Dongfeng; Xie Dong; Ho Yukun; Yang Fujia

    2001-01-01

    This paper is devoted to discuss a new method to directly extract the information of the geometric self-absorption correction through the measurement of characteristic γ radiation emitted spontaneously from nuclear fissile material. The numerical simulation tests show that this method can extract the purely original information needed for nondestructive assay method by the γ-ray spectra to be measured, even though the geometric shape of the sample and materials between sample and detector are not known in advance. (author)

  16. Mathematic models for a ray tracing method and its applications in wireless optical communications.

    Science.gov (United States)

    Zhang, Minglun; Zhang, Yangan; Yuan, Xueguang; Zhang, Jinnan

    2010-08-16

    This paper presents a new ray tracing method, which contains a whole set of mathematic models, and its validity is verified by simulations. In addition, both theoretical analysis and simulation results show that the computational complexity of the method is much lower than that of previous ones. Therefore, the method can be used to rapidly calculate the impulse response of wireless optical channels for complicated systems.

  17. Diffractometric method for obtaining of x-ray diffraction patterns of transplutonium element compounds

    International Nuclear Information System (INIS)

    Dubasov, Yu.V.; Aleksandrov, B.M.; Baranov, Yu.I.; Golubev, V.A.; Nikolaev, V.B.

    1986-01-01

    Method allowing to carry out X-ray radiographic investigations of powders of high radioactive α-sources (transuranium and transplutonium compounds) by the diffractometric method have been developed. The method is tested for three americium compounds crystallizing in different syngonies - dioxide, formiate, oxalate. The substance quantity necessary for analysis is 0.5-1 mg. The investigations can be carried out with diffractometers of general purpose of DRON-UMI and DRON-20 types

  18. Statistical analysis of x-ray stress measurement by centroid method

    International Nuclear Information System (INIS)

    Kurita, Masanori; Amano, Jun; Sakamoto, Isao

    1982-01-01

    The X-ray technique allows a nondestructive and rapid measurement of residual stresses in metallic materials. The centroid method has an advantage over other X-ray methods in that it can determine the angular position of a diffraction line, from which the stress is calculated, even with an asymmetrical line profile. An equation for the standard deviation of the angular position of a diffraction line, σsub(p), caused by statistical fluctuation was derived, which is a fundamental source of scatter in X-ray stress measurements. This equation shows that an increase of X-ray counts by a factor of k results in a decrease of σsub(p) by a factor of 1/√k. It also shows that σsub(p) increases rapidly as the angular range used in calculating the centroid increases. It is therefore important to calculate the centroid using the narrow angular range between the two ends of the diffraction line where it starts to deviate from the straight background line. By using quenched structural steels JIS S35C and S45C, the residual stresses and their standard deviations were calculated by the centroid, parabola, Gaussian curve, and half-width methods, and the results were compared. The centroid of a diffraction line was affected greatly by the background line used. The standard deviation of the stress measured by the centroid method was found to be the largest among the four methods. (author)

  19. A novel method for quantitative geosteering using azimuthal gamma-ray logging

    International Nuclear Information System (INIS)

    Yuan, Chao; Zhou, Cancan; Zhang, Feng; Hu, Song; Li, Chaoliu

    2015-01-01

    A novel method for quantitative geosteering by using azimuthal gamma-ray logging is proposed. Real-time up and bottom gamma-ray logs when a logging tool travels through a boundary surface with different relative dip angles are simulated with the Monte Carlo method. Study results show that response points of up and bottom gamma-ray logs when the logging tool moves towards a highly radioactive formation can be used to predict the relative dip angle, and then the distance from the drilling bit to the boundary surface is calculated. - Highlights: • A new method is proposed for geosteering by using azimuthal gamma-ray logging. • The new method can quantitatively determine the distance from the drilling bit to the boundary surface while the traditional geosteering method can only qualitatively guide the drilling bit in reservoirs. • The response points of real-time upper and lower gamma line when the logging tool meets high radioactive formation are used to predict the relative dip angles, and then the distance from the drilling bit to the boundary surface is calculated

  20. A simple identification method for spore-forming bacteria showing high resistance against γ-rays

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko; Sone, Koji; Kobayashi, Toshikazu

    1993-01-01

    A simple identification method was developed for spore-forming bacteria which are highly resistant against γ-rays. Among 23 species of Bacillus studied, the spores of Bacillus megaterium, B. cereus, B. thuringiensis, B. pumilus and B. aneurinolyticus showed high resistance against γ-rays as compared with other spores of Bacillus species. Combination of the seven kinds of biochemical tests, namely, the citrate utilization test, nitrate reduction test, starch hydrolysis test, Voges-Proskauer reaction test, gelatine hydrolysis test, mannitol utilization test and xylose utilization test showed a characteristic pattern for each species of Bacillus. The combination pattern of each the above tests with a few supplementary test, if necessary, was useful to identify Bacillus species showing high radiation resistance against γ-rays. The method is specific for B. megaterium, B. thuringiensis and B. pumilus, and highly selective for B. aneurinolyticus and B. cereus. (author)

  1. Application of the nuclear x-ray fluorescence method to prospecting for gold in-situ

    International Nuclear Information System (INIS)

    Zhang, Y.; Xie, T.; Zhou, S.; Ge, L.

    1989-01-01

    Arsenic and chalcophile elements are often associated with gold, and can be considered indicator elements when prospecting for gold deposits. The nuclear geophysics X-ray fluorescence method can be used to search for hidden gold deposits by measuring fluorescence intensities of the indicator elements in situ. The method can speed geologic investigation and reduce exploration cost. Three types of portable radioisotope X-ray fluorescence analyzers, designed and manufactured by Chengdu College of Geology and Chongqing Geological Instrument Factory, are briefly introduced. These analyzers are widely used in different stages of geologic investigation for gold in China. In the two case histories presented five anomalous zones of X-ray fluorescence intensity related to gold mineralization are located and one hidden gold deposit is discovered with gold content of 23 g/t

  2. Non-contact micro mass evaluation method using an X-ray microscope

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jiseok; Sun, Gwang Min; Baek, Ha Ni; Hoang, Sy Minh Tuan; Park, Sun Ae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-07-15

    For the mass inspection of attached foils such as printed electrodes, mass should be measured by a non-contact method with the capacity to measure a small mass of micrograms. In this study, the masses of 1 mg to 10 mg electrodes were evaluated using an X-ray microscope. The results were compared with the masses determined by using a digital scale with a 0.005 mg error. The average of the relative error between the mass measurements using the X-ray microscope and those using the digital scale was less than 2.51%. The results show that X-ray mass evaluation method can be used for mass measurement of micro objects by replacing a digital scale.

  3. Development of X-ray radiography examination technology by image processing method

    Energy Technology Data Exchange (ETDEWEB)

    Min, Duck Kee; Koo, Dae Seo; Kim, Eun Ka [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    Because the dimension of nuclear fuel rods was measured with rapidity and accuracy by X-ray radiography examination, the set-up of image processing system which was composed of 979 CCD-L camera, image processing card and fluorescent lighting was carried out, and the image processing system enabled image processing to perform. The examination technology of X-ray radiography, which enabled dimension measurement of nuclear fuel rods to perform, was developed by image processing method. The result of dimension measurement of standard fuel rod by image processing method was 2% reduction in relative measuring error than that of X-ray radiography film, while the former was better by 100 {approx} 200 {mu}m in measuring accuracy than the latter. (author). 9 refs., 22 figs., 3 tabs.

  4. The reduction methods of operator's radiation dose for portable dental X-ray machines.

    Science.gov (United States)

    Cho, Jeong-Yeon; Han, Won-Jeong

    2012-08-01

    This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-ray tubehead and at the operator's chest and waist levels with and without the backscatter shield. The operator's radiation dose at the hand level was measured with and without lead gloves and with long and short cones. The backscatter shield reduced operator's radiation dose at the hand level of X-ray tubehead to 23 - 32%, the lead gloves to 26 - 31%, and long cone to 48 - 52%. And the backscatter shield reduced operator's radiation dose at the operator's chest and waist levels to 0.1 - 37%. When portable dental X-ray systems are used, it is recommended to select X-ray machine attached with a backscatter shield and a long cone and to wear the lead gloves.

  5. Applications of the Warren-Averbach method of X-ray diffraction line profile analysis

    International Nuclear Information System (INIS)

    Ichikawa, Rodrigo Uchida

    2013-01-01

    The objective of this work was to develop and implement a methodology of X-ray Line Profile Analysis (XLPA) for the study and determination of the mean crystallite sizes and microstrains in materials. A computer program was developed to speed up the treatment of diffraction peaks and perform the deconvolution utilizing the Stokes method to correct the instrumental contribution in the X-ray diffraction measurements. The XLPA methods used were the Scherrer, Williamson-Hall and Single-Line methods, which can be called real space methods, and the Fourier space method of Warren-Averbach. Furthermore, considering a mathematical modelling it was possible to calculate the crystallite size distribution, considering the log-normal distribution and spherical crystallites. It was possible to demonstrate the proposed theory can provide reliable results evaluating a dispersion parameter. The methodologies described above were applied in two distinct materials: in the alloy Zircaloy-4 and in ZnO. (author)

  6. A wavelet-based Gaussian method for energy dispersive X-ray fluorescence spectrum

    Directory of Open Access Journals (Sweden)

    Pan Liu

    2017-05-01

    Full Text Available This paper presents a wavelet-based Gaussian method (WGM for the peak intensity estimation of energy dispersive X-ray fluorescence (EDXRF. The relationship between the parameters of Gaussian curve and the wavelet coefficients of Gaussian peak point is firstly established based on the Mexican hat wavelet. It is found that the Gaussian parameters can be accurately calculated by any two wavelet coefficients at the peak point which has to be known. This fact leads to a local Gaussian estimation method for spectral peaks, which estimates the Gaussian parameters based on the detail wavelet coefficients of Gaussian peak point. The proposed method is tested via simulated and measured spectra from an energy X-ray spectrometer, and compared with some existing methods. The results prove that the proposed method can directly estimate the peak intensity of EDXRF free from the background information, and also effectively distinguish overlap peaks in EDXRF spectrum.

  7. The study on the X-ray correction method of long fracture displacement

    International Nuclear Information System (INIS)

    Jia Bin; Huang Ailing; Chen Fuzhong; Men Chunyan; Sui Chengzong; Cui Yiming; Yang Yundong

    2010-01-01

    Objective: To explore the image correction of fracture displacement by conventional X-ray photography (ortho tropic and lateral) and test by computed tomography (CT). Methods: The correction method of fracture displacement was designed according to geometry of X-ray photography. Selected one midhumeral fracture specimen which designed with lateral shift and angular displacement, and scanned from anteroposterior and position respectively, and also volume scanned using CT, the data obtained from volume scan were processed using multiplanar reconstruction (MPR) and shaded surface display (SSD). The displacement data relied on X-ray image, CT with MPR and SSD processing, actual design of specimens were compared respectively. Results: The direction and degree of displacement among correction data of X-ray images and the data from MPR and SSD, actual design of specimen were little difference, location difference <1.5 mm, degree difference <1.5 degree. Conclusion: It is really reliable for fracture displacement by conventional X-ray photography with coordinate correction, and it is helpful to obviously improve the diagnostic accuracy of the degree of fracture displacement. (authors)

  8. A nonlinear wavelet method for data smoothing of low-level gamma-ray spectra

    International Nuclear Information System (INIS)

    Gang Xiao; Li Deng; Benai Zhang; Jianshi Zhu

    2004-01-01

    A nonlinear wavelet method was designed for smoothing low-level gamma-ray spectra. The spectra of a 60 Co graduated radioactive source and a mixed soil sample were smoothed respectively according to this method and a 5 point smoothing method. The FWHM of 1,332 keV peak of 60 Co source and the absolute activities of 238 U of soil sample were calculated. The results show that the nonlinear wavelet method is better than the traditional method, with less loss of spectral peak and a more complete reduction of statistical fluctuation. (author)

  9. Rating of the X-ray method of measurement of stresses in steels

    International Nuclear Information System (INIS)

    Skrzypinski, A.

    1977-01-01

    The possibilities of utilization of some dependencies occuring in the X-ray technique of measurement of natural stresses for determination of distances of a between - plane lattice without natural stresses (d 0 ) are discussed. The proposed methodics of determination of d 0 is illustrated with the investigations which were carried-out on bearing steel LH15. (author)

  10. The X-ray fluorescent method for determination of total sulphur in bituminous coals

    International Nuclear Information System (INIS)

    Widowska-Kusmierska, J.; Siess, K.

    1979-01-01

    The X-ray fluorescent technique for the determination of total sulphur covering concentrations from 0,1 to 10% has been applied for bituminous coals showing a great variability in qualitative and quantitative composition of mineral matter (ash). The described method is a quick one giving results during one hour. The obtained good accuracy of determinations gives prospects for wide industrial application. (author)

  11. A greedy method for reconstructing polycrystals from three-dimensional X-ray diffraction data

    DEFF Research Database (Denmark)

    Kulshreshth, Arun Kumar; Alpers, Andreas; Herman, Gabor T.

    2009-01-01

    An iterative search method is proposed for obtaining orientation maps inside polycrystals from three-dimensional X-ray diffraction (3DXRD) data. In each step, detector pixel intensities are calculated by a forward model based on the current estimate of the orientation map. The pixel at which...

  12. Matching methods evaluation framework for stereoscopic breast x-ray images.

    Science.gov (United States)

    Rousson, Johanna; Naudin, Mathieu; Marchessoux, Cédric

    2016-01-01

    Three-dimensional (3-D) imaging has been intensively studied in the past few decades. Depth information is an important added value of 3-D systems over two-dimensional systems. Special focuses were devoted to the development of stereo matching methods for the generation of disparity maps (i.e., depth information within a 3-D scene). Dedicated frameworks were designed to evaluate and rank the performance of different stereo matching methods but never considering x-ray medical images. Yet, 3-D x-ray acquisition systems and 3-D medical displays have already been introduced into the diagnostic market. To access the depth information within x-ray stereoscopic images, computing accurate disparity maps is essential. We aimed at developing a framework dedicated to x-ray stereoscopic breast images used to evaluate and rank several stereo matching methods. A multiresolution pyramid optimization approach was integrated to the framework to increase the accuracy and the efficiency of the stereo matching techniques. Finally, a metric was designed to score the results of the stereo matching compared with the ground truth. Eight methods were evaluated and four of them [locally scaled sum of absolute differences (LSAD), zero mean sum of absolute differences, zero mean sum of squared differences, and locally scaled mean sum of squared differences] appeared to perform equally good with an average error score of 0.04 (0 is the perfect matching). LSAD was selected for generating the disparity maps.

  13. Cone Beam X-ray Luminescence Computed Tomography Based on Bayesian Method.

    Science.gov (United States)

    Zhang, Guanglei; Liu, Fei; Liu, Jie; Luo, Jianwen; Xie, Yaoqin; Bai, Jing; Xing, Lei

    2017-01-01

    X-ray luminescence computed tomography (XLCT), which aims to achieve molecular and functional imaging by X-rays, has recently been proposed as a new imaging modality. Combining the principles of X-ray excitation of luminescence-based probes and optical signal detection, XLCT naturally fuses functional and anatomical images and provides complementary information for a wide range of applications in biomedical research. In order to improve the data acquisition efficiency of previously developed narrow-beam XLCT, a cone beam XLCT (CB-XLCT) mode is adopted here to take advantage of the useful geometric features of cone beam excitation. Practically, a major hurdle in using cone beam X-ray for XLCT is that the inverse problem here is seriously ill-conditioned, hindering us to achieve good image quality. In this paper, we propose a novel Bayesian method to tackle the bottleneck in CB-XLCT reconstruction. The method utilizes a local regularization strategy based on Gaussian Markov random field to mitigate the ill-conditioness of CB-XLCT. An alternating optimization scheme is then used to automatically calculate all the unknown hyperparameters while an iterative coordinate descent algorithm is adopted to reconstruct the image with a voxel-based closed-form solution. Results of numerical simulations and mouse experiments show that the self-adaptive Bayesian method significantly improves the CB-XLCT image quality as compared with conventional methods.

  14. Envelope method for background elimination from X-ray fluorescence spectra

    International Nuclear Information System (INIS)

    Monakhov, V.V.; Naumenko, P.A.; Chashinskaya, O.A.

    2006-01-01

    The influence of the background noise caused by Bremsstrahlung on the accuracy of the envelope method at x-ray fluorescence spectra processing is studied. This is carried out by the example of model spectra at different forms of Bremsstrahlung noise as well as at the presence of background noise in spectra. The interpolation by parabolic splines is used for the estimation of the error of the envelope method for the elimination of continuos background noise. It is found out that the error of the proposed method constitutes decimal parts of percent. It is shown that the envelope method is the effective technique for the elimination of the continuous Bremsstrahlung from x-ray fluorescence spectra of the first order [ru

  15. Residual stress measurement by X-ray diffraction with the Gaussian curve method and its automation

    International Nuclear Information System (INIS)

    Kurita, M.

    1987-01-01

    X-ray technique with the Gaussian curve method and its automation are described for rapid and nondestructive measurement of residual stress. A simplified equation for measuring the stress by the Gaussian curve method is derived because in its previous form this method required laborious calculation. The residual stress can be measured in a few minutes, depending on materials, using an automated X-ray stress analyzer with a microcomputer which was developed in the laboratory. The residual stress distribution of a partially induction hardened and tempered (at 280 0 C) steel bar was measured with the Gaussian curve method. A sharp residual tensile stress peak of 182 MPa appeared right outside the hardened region at which fatigue failure is liable to occur

  16. Comparative study on γ-ray spectrum by several filtering method

    International Nuclear Information System (INIS)

    Yuan Xinyu; Liu Liangjun; Zhou Jianliang

    2011-01-01

    Comparative study was conducted on results of gamma-ray spectrum by using a majority of active smoothing method, which were used to show filtering effect. The results showed that peak was widened and overlap peaks increased with energy domain filter in γ-ray spectrum. Filter and its parameters should be seriously taken into consideration in frequency domain. Wavelet transformation can keep signal in high frequency region well. Improved threshold method showed the advantages of hard and soft threshold method at the same time by comparison, which was suitable for weak peaks detection. A new filter was put forward to eke out gravity model approach, whose denoise level was detected by standard deviation. This method not only kept signal and net area of peak well,but also attained better result and had simple computer program. (authors)

  17. A convenient method for X-ray analysis in TEM that measures mass thickness and composition

    Science.gov (United States)

    Statham, P.; Sagar, J.; Holland, J.; Pinard, P.; Lozano-Perez, S.

    2018-01-01

    We consider a new approach for quantitative analysis in transmission electron microscopy (TEM) that offers the same convenience as single-standard quantitative analysis in scanning electron microscopy (SEM). Instead of a bulk standard, a thin film with known mass thickness is used as a reference. The procedure involves recording an X-ray spectrum from the reference film for each session of acquisitions on real specimens. There is no need to measure the beam current; the current only needs to be stable for the duration of the session. A new reference standard with a large (1 mm x 1 mm) area of uniform thickness of 100 nm silicon nitride is used to reveal regions of X-ray detector occlusion that would give misleading results for any X-ray method that measures thickness. Unlike previous methods, the new X-ray method does not require an accurate beam current monitor but delivers equivalent accuracy in mass thickness measurement. Quantitative compositional results are also automatically corrected for specimen self-absorption. The new method is tested using a wedge specimen of Inconel 600 that is used to calibrate the high angle angular dark field (HAADF) signal to provide a thickness reference and results are compared with electron energy-loss spectrometry (EELS) measurements. For the new X-ray method, element composition results are consistent with the expected composition for the alloy and the mass thickness measurement is shown to provide an accurate alternative to EELS for thickness determination in TEM without the uncertainty associated with mean free path estimates.

  18. Long wave-length x-ray diffraction crystal and method of manufacturing same

    International Nuclear Information System (INIS)

    Zingaro, W.P.; Sicignano, A.

    1980-01-01

    An x-ray diffraction crystal of the Langemuir-Blodgett type capable of detecting radiation having a wavelength greater than 50 Arystroms and a method of making such a crystal are described. The crystal consists of a pair of alternate monolayers, one a heavy metal soap, and one a light metal soap. Selecting cation pairs with a significant difference in atomic number and dispersing power, such as Pb and Be, Mg, or Ca, increases the effective interplanar distance since the Pb planes cause the predominant x-ray diffraction. (LL)

  19. Note: A novel method for in situ loading of gases via x-ray induced chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan (UNLV); (CIW)

    2011-12-14

    We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO{sub 3}) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

  20. Note: A novel method for in situ loading of gases via x-ray induced chemistry

    Science.gov (United States)

    Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan

    2011-10-01

    We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO3) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

  1. Advanced x-ray stress analysis method for a single crystal using different diffraction plane families

    International Nuclear Information System (INIS)

    Imafuku, Muneyuki; Suzuki, Hiroshi; Sueyoshi, Kazuyuki; Akita, Koichi; Ohya, Shin-ichi

    2008-01-01

    Generalized formula of the x-ray stress analysis for a single crystal with unknown stress-free lattice parameter was proposed. This method enables us to evaluate the plane stress states with any combination of diffraction planes. We can choose and combine the appropriate x-ray sources and diffraction plane families, depending on the sample orientation and the apparatus, whenever diffraction condition is satisfied. The analysis of plane stress distributions in an iron single crystal was demonstrated combining with the diffraction data for Fe{211} and Fe{310} plane families

  2. Detection methods of pulsed X-rays for transmission tomography with a linear accelerator

    International Nuclear Information System (INIS)

    Glasser, F.

    1988-07-01

    Appropriate detection methods are studied for the development of a high energy tomograph using a linear accelerator for nondestructive testing of bulky objects. The aim is the selection of detectors adapted to a pulsed X-ray source and with a good behavior under X-ray radiations of several MeV. Performance of semiconductors (HgI 2 , Cl doped CdTe, GaAs, Bi 12 Ge0 20 ) and a scintillator (Bi 4 Ge 3 0 12 ) are examined. A prototype tomograph gave images that show the validity of detectors for analysis of medium size equipment such as a concrete drum of 60 cm in diameter [fr

  3. Preliminary study of determination of UO2 grain size using X-ray diffraction method

    International Nuclear Information System (INIS)

    Mulyana, T.; Sambodo, G. D.; Juanda, D.; Fatchatul, B.

    1998-01-01

    The determination of UO 2 grain size has accomplished using x-ray diffraction method. The UO 2 powder is obtained from sol-gel process. A copper target as radiation source in the x-ray diffractometer was used in this experiment with CμKα characteristic wavelength 1.54433 Angstrom. The result indicate that the UO 2 mean grain size on presintered (temperature 800 o C) has the value 456.8500 Angstrom and the UO 2 mean grain size on sintered (temperature 1700 o C) has value 651.4934 Angstrom

  4. Radiation exposure in X-ray angiography and comparisons between digital and conventional methods of imaging

    International Nuclear Information System (INIS)

    Schaberg, J.

    1987-01-01

    The more recent developments and techniques in the field of angiography are examined for associated radiation exposure risks for patients and investigators and then compared to the conventional methods of angiography. It could be shown that digital subtraction angiography is generally associated with a lesser risk of somatic exposure of the patient, provided that the equipment used offers an adjustable useful-beam range and focus. The fact that above-table X-ray tubes are now generally replaced with X-ray systems installed under the examination table permits the relatively high doses, to which investigators are exposed during angiography, to be reduced by a factor of 3. (DG) [de

  5. X-ray photon-in/photon-out methods for chemical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Matthew A.

    2010-03-24

    Most interesting materials in nature are heterogeneous, so it is useful to have analytical techniques with spatial resolution sufficient to resolve these heterogeneities.This article presents the basics of X-ray photon-in/photon-out chemical imaging. This family of methods allows one to derive images reflectingthe chemical state of a given element in a complex sample, at micron or deep sub-micron scale. X-ray chemical imaging is relatively non-destructiveand element-selective, and requires minimal sample preparation. The article presents the basic concepts and some considerations of data takingand data analysis, along with some examples.

  6. Synchrotron x-ray methods in studies of thin organic film structure

    International Nuclear Information System (INIS)

    Gentle, I.

    2002-01-01

    Full text: In recent years, the study of the structures of organic films as thin as a single monolayer has been revolutionized by methods that take advantage of the characteristics of synchrotron radiation. In particular, the methods of grazing incidence X-ray diffraction (GIXD) and X-ray reflectivity have led to a number of valuable insights into structural aspects of thin films at molecular resolution. Our group has been studying films formed at the air/water interface as insoluble monolayers and subsequently transferred to solid substrates using either the vertical (Langmuir-Blodgett) or horizontal (Langmuir-Schaeffer) methods. The main aim of these experiments is to exert control over film structure in the direction parallel to the substrate surface. This is highly desirable in order to design devices that exploit the optical and electrooptical properties of functional materials, but is difficult to do. By varying the chemical structure of the film materials and controlling deposition conditions a degree of control is possible, but only using synchrotron methods can it be easily verified. We have also developed a novel method of rapidly collecting data from GIXD measurements by the application of area detection (imaging plates), which has made possible measurements of dynamic processes such as in-situ annealing. Such measurements are not possible using traditional scanning methods. One area of current interest is films composed of porphyrins as functional materials, either alone or as mixed films with fatty acids. We have been investigating ways of assembling porphyrins in such a way as to overcome the tendency to aggregate, and to produce patterning and ordered structures in the plane of the interface. Examples will be given of how film composition and deposition method affects the final structure, and of how X-ray methods can be used to elucidate both the structures and the mechanisms. Copyright (2002) Australian X-ray Analytical Association Inc

  7. Image combination enhancement method for X-ray compton back-scattering security inspection body scanner

    International Nuclear Information System (INIS)

    Wang Huaiying; Zhang Yujin; Yang Lirui; Li Dong

    2011-01-01

    As for X-ray Compton Back-Scattering (CBS) body scanner, image clearness is very important for the performance of detecting the contraband hidden on the body. A new image combination enhancement method is provided based on characteristics of CBS body images and points of human vision. After processed by this method, the CBS image will be obviously improved with clear levels, distinct outline and uniform background. (authors)

  8. Methods for the analysis of overlapped peaks in analytical gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Sterlinski, S.; Wasek, M.

    1989-01-01

    A review of critical evaluation of simple methods for the analysis of overlapped peaks from the point of view of their applicability in activation analysis are described. These methods are adopted from other spectroscopic techniques and gas chromatography. The experimental verification has been carried out for gamma-ray spectra in the energy range 120 KeV - 3 MeV. 28 refs., 8 figs., 3 tabs. (author)

  9. A method for exploring the distribution of radioelements at depth using gamma-ray spectrometric data

    International Nuclear Information System (INIS)

    Li Qingyang

    1997-01-01

    Based on the inherent relation between radioelements and terrestrial heat flow, theoretically shows the possibility of exploring the distribution of radioelements at depth using gamma-ray spectrometric data, and a data-processing and synthesizing method has been adopted to deduce the calculation formula. The practical application in the uranium mineralized area No. 2801 in Yunnan Province proves that this method is of practical value, and it has been successfully applied to the data processing and good results have been obtained

  10. Method and multichannel equipment for chemical analysis by X-ray emission

    International Nuclear Information System (INIS)

    Bacso, J.; Horkay, Gy.; Kalinka, G.; Kertesz, Zs.; Kiss Varga, M.; Lakatos, T.; Mathe, Gy.; Paal, A.; Sulik, B.

    1978-01-01

    In the patent a simple method and an apparatus are described for chemical analysis based on X-ray emission generated by irradiation. The concentrations of pre-selected elements can be determined easily by this method using an equipment containing microprocessor. The number of channels and the elements to be determined can be modified by a simple change in the program. (Sz.J.)

  11. Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

    International Nuclear Information System (INIS)

    Liu Yanyang; Liu Qingcheng; Zhang Zhiyong

    2008-01-01

    The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

  12. Method of producing a pseudo-color photograph with X-rays

    International Nuclear Information System (INIS)

    Tajima, Mataichi.

    1965-01-01

    Conventional black and white X-ray photography cannot simultaneously produce an image on photographic film of a subject having regions of high and low X-ray absorption due to the limitation of photographic density range, gradation and exposure tolerance. This invention records both regions as images of different colors on the same color photographic film. According to a method of this invention for making an X-ray pseudo-color photograph, the subject is directly irradiated by an X-ray beam emergent from an X-ray beam generator, and an X-ray permeation image of the subject is converted into and displayed as a visible light image by means of a fluorescent screen. In one aspect of this invention, there is used a color photographic film which has at least two kinds of sensitive and coloring layers exhibiting the same sensitivity. During the period in which the visible image is displayed, the film is exposed to the visible light in such a way that at least two color filters differing in color and density are successively interposed between the film and the fluorescent screen. In another aspect, a color photographic film is employed having at least two kinds of sensitive and coloring layers exhibiting different sensitivities. During the period in which the visible image is displayed, the film is exposed to visible light by sequentially interposing at least two color filters of different color but of equal density. In this manner, regions comparatively low in X-ray absorption, such as the lungs, and regions comparatively high in absorption, such as the heart, appear as, for example, a blue image and a red image on the color photographic film, respectively. (Takasuka, S.)

  13. Method of producing a pseudo-color photograph with X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, M

    1965-05-08

    Conventional black and white X-ray photography cannot simultaneously produce an image on photographic film of a subject having regions of high and low X-ray absorption due to the limitation of photographic density range, gradation and exposure tolerance. This invention records both regions as images of different colors on the same color photographic film. According to a method of this invention for making an X-ray pseudo-color photograph, the subject is directly irradiated by an X-ray beam emergent from an X-ray beam generator, and an X-ray permeation image of the subject is converted into and displayed as a visible light image by means of a fluorescent screen. In one aspect of this invention, there is used a color photographic film which has at least two kinds of sensitive and coloring layers exhibiting the same sensitivity. During the period in which the visible image is displayed, the film is exposed to the visible light in such a way that at least two color filters differing in color and density are successively interposed between the film and the fluorescent screen. In another aspect, a color photographic film is employed having at least two kinds of sensitive and coloring layers exhibiting different sensitivities. During the period in which the visible image is displayed, the film is exposed to visible light by sequentially interposing at least two color filters of different color but of equal density. In this manner, regions comparatively low in X-ray absorption, such as the lungs, and regions comparatively high in absorption, such as the heart, appear as, for example, a blue image and a red image on the color photographic film, respectively.

  14. Inspection method of optical fiber preforms by x-ray absorption measurements

    International Nuclear Information System (INIS)

    Takahashi, H.; Nakamura, K.; Shibuya, S.; Kuroha, T.

    1980-01-01

    A method for measuring the refractive index distribution of optical fiber preforms has been developed by application of the theory of X-ray radiography. The composition of quartz optical fiber materials is, in most cases, limited to the group of five elements - Ge, P, Si, O and B. Of them, Ge is an essential element to determine the structure of refractive index of an optical fiber and the distribution of its density can be regarded approximately as the distribution of refractive index. On the other hand, the coefficient of low-energy X-ray absorption by the elements depends markedly on their atomic numbers, and Ge has a far larger absorption coefficient than the other four elements. Therefore, analysis of the intensity of X-ray absorbed by optical fiber preforms makes it possible to determine the distribution of Ge density and consequently the distribution of refractive index. (author)

  15. Determination of Ti, Cr, Cu and Ta in niobium oxide by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Dixit, R.M.; Deshpande, S.S.

    1986-01-01

    An x-ray fluorescence method for the determination of Ti, Cr, Cu and Ta in niobium oxide has been developed. Samples/standards in powder form are mixed with boric acid in the proportion of 1:1 (400 mg. each). Double layer pellets are prepared by pressing this mixture over a primary boric acid pellet. Philips PW-1220, a semiautomatic x-ray spectrometer with tungsten target x-ray tube for excitation and LiF (200) crystal for dispersion have been used. The determination range is from 0.005 to 0.1per cent for Ti and Cr, 0.01 to 0.1per cent for Cu and 0.05 to 1per cent for Ta. (author)

  16. Note: Loading method of molecular fluorine using x-ray induced chemistry

    International Nuclear Information System (INIS)

    Pravica, Michael; Sneed, Daniel; White, Melanie; Wang, Yonggang

    2014-01-01

    We have successfully loaded molecular fluorine into a diamond anvil cell at high pressure using the synchrotron x-ray induced decomposition of perfluorohexane (C 6 F 14 ). “White” x-ray radiation from the Advanced Photon Source was used to initiate the chemical decomposition of C 6 F 14 , which resulted in the in situ production of F 2 as verified via Raman spectroscopy. Due to the toxic nature of fluorine, this method will offer significant advantages in the ability to easily load a relatively nontoxic and inert substance into a chamber (such as a diamond anvil cell) that, when sealed with other reactants and irradiate with hard x-rays (>7 keV), releases highly reactive and toxic fluorine into the sample/reaction chamber to enable novel chemical synthesis under isolated and/or extreme conditions

  17. Method and apparatus for measuring incombustible content of coal mine dust using gamma-ray backscatter

    International Nuclear Information System (INIS)

    Armstrong, F.E.

    1976-01-01

    A method and apparatus for measuring incombustible content of particulate material, particularly coal mine dust, include placing a sample of the particulate material in a container to define a pair of angularly oriented surfaces of the sample, directing an incident gamma-ray beam from a radiation source at one surface of the sample and detecting gamma-ray backscatter from the other surface of the sample with a radiation detector having an output operating a display to indicate incombustible content of the sample. The positioning of the source and detector along different surfaces of the sample permits the depth of the scattering volume defined by intersection of the incident beam and a detection cone from the detector to be selected such that variations in scattered radiation produced by variations in density of the sample are compensated by variations in the attenuation of the incident beam and the gamma-ray backscatter. 17 claims 5 figures

  18. Final Report for X-ray Diffraction Sample Preparation Method Development

    Energy Technology Data Exchange (ETDEWEB)

    Ely, T. M. [Hanford Site (HNF), Richland, WA (United States); Meznarich, H. K. [Hanford Site (HNF), Richland, WA (United States); Valero, T. [Hanford Site (HNF), Richland, WA (United States)

    2018-01-30

    WRPS-1500790, “X-ray Diffraction Saltcake Sample Preparation Method Development Plan/Procedure,” was originally prepared with the intent of improving the specimen preparation methodology used to generate saltcake specimens suitable for XRD-based solid phase characterization. At the time that this test plan document was originally developed, packed powder in cavity supports with collodion binder was the established XRD specimen preparation method. An alternate specimen preparation method less vulnerable, if not completely invulnerable to preferred orientation effects, was desired as a replacement for the method.

  19. On the methods of determination of x-ray sources protection quality in x-ray diagnostic equipment

    International Nuclear Information System (INIS)

    Vladimirov, L.V.

    1973-01-01

    Existing procedures for assessing the quality of shielding of X-ray radiators are compared; these procedures are shown to have a number of shortcomings and to be very time-consuming. A procedure is offered in which shielding quality is tested in two stages: (1) X-ray tests aimed at determining the quality of protection of the X-ray tube unit; and (2) dosimeter tests proper. The results of measurements are compared with maximum permissible dosage rate

  20. The Global Survey Method Applied to Ground-level Cosmic Ray Measurements

    Science.gov (United States)

    Belov, A.; Eroshenko, E.; Yanke, V.; Oleneva, V.; Abunin, A.; Abunina, M.; Papaioannou, A.; Mavromichalaki, H.

    2018-04-01

    The global survey method (GSM) technique unites simultaneous ground-level observations of cosmic rays in different locations and allows us to obtain the main characteristics of cosmic-ray variations outside of the atmosphere and magnetosphere of Earth. This technique has been developed and applied in numerous studies over many years by the Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN). We here describe the IZMIRAN version of the GSM in detail. With this technique, the hourly data of the world-wide neutron-monitor network from July 1957 until December 2016 were processed, and further processing is enabled upon the receipt of new data. The result is a database of homogeneous and continuous hourly characteristics of the density variations (an isotropic part of the intensity) and the 3D vector of the cosmic-ray anisotropy. It includes all of the effects that could be identified in galactic cosmic-ray variations that were caused by large-scale disturbances of the interplanetary medium in more than 50 years. These results in turn became the basis for a database on Forbush effects and interplanetary disturbances. This database allows correlating various space-environment parameters (the characteristics of the Sun, the solar wind, et cetera) with cosmic-ray parameters and studying their interrelations. We also present features of the coupling coefficients for different neutron monitors that enable us to make a connection from ground-level measurements to primary cosmic-ray variations outside the atmosphere and the magnetosphere. We discuss the strengths and weaknesses of the current version of the GSM as well as further possible developments and improvements. The method developed allows us to minimize the problems of the neutron-monitor network, which are typical for experimental physics, and to considerably enhance its advantages.

  1. The methods for detecting multiple small nodules from 3D chest X-ray CT images

    International Nuclear Information System (INIS)

    Hayase, Yosuke; Mekada, Yoshito; Mori, Kensaku; Toriwaki, Jun-ichiro; Natori, Hiroshi

    2004-01-01

    This paper describes a method for detecting small nodules, whose CT values and diameters are more than -600 Hounsfield unit (H.U.) and 2 mm, from three-dimensional chest X-ray CT images. The proposed method roughly consists of two submodules: initial detection of nodule candidates by discriminating between nodule regions and other regions such as blood vessels or bronchi using a shape feature computed from distance values inside the regions and reduction of false positive (FP) regions by using a minimum directional difference filter called minimum directional difference filter (Min-DD) changing its radius suit to the size of the initial candidates. The performance of the proposed method was evaluated by using seven cases of chest X-ray CT images including six abnormal cases where multiple lung cancers are observed. The experimental results for nodules (361 regions in total) showed that sensitivity and FP regions are 71% and 7.4 regions in average per case. (author)

  2. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    International Nuclear Information System (INIS)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich; Nares, Chankow; Hao, Quang Nguyen

    2016-01-01

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method

  3. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    Energy Technology Data Exchange (ETDEWEB)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich, E-mail: phongphaeth.p@chula.ac.th; Nares, Chankow [Nuclear Engineering Department, Faculty of Engineering, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Hao, Quang Nguyen [Vietnam Atomic Energy Institute, Ministry of Science and Technology, Hanoi (Viet Nam)

    2016-01-22

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  4. Activity measurement by using γ-ray sum peak method considering intake radioactivity and its application

    International Nuclear Information System (INIS)

    Miyahara, Hiroshi; Narita, Norihiko; Tomita, Kenichi; Katoh, Yoshichika; Mori, Chizuo; Momose, Takumaro; Shinohara, Kunihiko

    2000-01-01

    It is important to measure external and internal exposure dose in the case of accident. The external exposure can be measured by various dosimeters, but the internal exposure is usually calculated from estimated amounts of intake radioactivity because of difficulty of direct measurement. Detection efficiency of human counter used in direct measurement is necessary, but there is no effective method to determine it for non-uniform distribution. The γ-ray sum peak method is tried for the cascade γ-ray emitter under the consideration of small diffusion such as just after intake. After disintegration rates of sources of 46 Sc and 60 Co were determined by 4πβ-γ coincidence method, γ-ray spectra were measured at various positions. Calculated disintegration rates by sum peak method agreed with those by coincidence method within 10%. The similar results were obtained for distributed plural sources in restricted condition. It is also investigated as application for the case that the other nuclide is contained in it. Using peak-to-total ratios measured in advance, the disintegration rates were determined only from the peak intensities. In this case the results had systematic uncertainty of about 20%. (author)

  5. Correlation methods in optical metrology with state-of-the-art x-ray mirrors

    Science.gov (United States)

    Yashchuk, Valeriy V.; Centers, Gary; Gevorkyan, Gevork S.; Lacey, Ian; Smith, Brian V.

    2018-01-01

    The development of fully coherent free electron lasers and diffraction limited storage ring x-ray sources has brought to focus the need for higher performing x-ray optics with unprecedented tolerances for surface slope and height errors and roughness. For example, the proposed beamlines for the future upgraded Advance Light Source, ALS-U, require optical elements characterized by a residual slope error of optics with a length of up to one meter. However, the current performance of x-ray optical fabrication and metrology generally falls short of these requirements. The major limitation comes from the lack of reliable and efficient surface metrology with required accuracy and with reasonably high measurement rate, suitable for integration into the modern deterministic surface figuring processes. The major problems of current surface metrology relate to the inherent instrumental temporal drifts, systematic errors, and/or an unacceptably high cost, as in the case of interferometry with computer-generated holograms as a reference. In this paper, we discuss the experimental methods and approaches based on correlation analysis to the acquisition and processing of metrology data developed at the ALS X-Ray Optical Laboratory (XROL). Using an example of surface topography measurements of a state-of-the-art x-ray mirror performed at the XROL, we demonstrate the efficiency of combining the developed experimental correlation methods to the advanced optimal scanning strategy (AOSS) technique. This allows a significant improvement in the accuracy and capacity of the measurements via suppression of the instrumental low frequency noise, temporal drift, and systematic error in a single measurement run. Practically speaking, implementation of the AOSS technique leads to an increase of the measurement accuracy, as well as the capacity of ex situ metrology by a factor of about four. The developed method is general and applicable to a broad spectrum of high accuracy measurements.

  6. Reconstruction method for fluorescent X-ray computed tomography by least-squares method using singular value decomposition

    Science.gov (United States)

    Yuasa, T.; Akiba, M.; Takeda, T.; Kazama, M.; Hoshino, A.; Watanabe, Y.; Hyodo, K.; Dilmanian, F. A.; Akatsuka, T.; Itai, Y.

    1997-02-01

    We describe a new attenuation correction method for fluorescent X-ray computed tomography (FXCT) applied to image nonradioactive contrast materials in vivo. The principle of the FXCT imaging is that of computed tomography of the first generation. Using monochromatized synchrotron radiation from the BLNE-5A bending-magnet beam line of Tristan Accumulation Ring in KEK, Japan, we studied phantoms with the FXCT method, and we succeeded in delineating a 4-mm-diameter channel filled with a 500 /spl mu/g I/ml iodine solution in a 20-mm-diameter acrylic cylindrical phantom. However, to detect smaller iodine concentrations, attenuation correction is needed. We present a correction method based on the equation representing the measurement process. The discretized equation system is solved by the least-squares method using the singular value decomposition. The attenuation correction method is applied to the projections by the Monte Carlo simulation and the experiment to confirm its effectiveness.

  7. Improved image alignment method in application to X-ray images and biological images.

    Science.gov (United States)

    Wang, Ching-Wei; Chen, Hsiang-Chou

    2013-08-01

    Alignment of medical images is a vital component of a large number of applications throughout the clinical track of events; not only within clinical diagnostic settings, but prominently so in the area of planning, consummation and evaluation of surgical and radiotherapeutical procedures. However, image registration of medical images is challenging because of variations on data appearance, imaging artifacts and complex data deformation problems. Hence, the aim of this study is to develop a robust image alignment method for medical images. An improved image registration method is proposed, and the method is evaluated with two types of medical data, including biological microscopic tissue images and dental X-ray images and compared with five state-of-the-art image registration techniques. The experimental results show that the presented method consistently performs well on both types of medical images, achieving 88.44 and 88.93% averaged registration accuracies for biological tissue images and X-ray images, respectively, and outperforms the benchmark methods. Based on the Tukey's honestly significant difference test and Fisher's least square difference test tests, the presented method performs significantly better than all existing methods (P ≤ 0.001) for tissue image alignment, and for the X-ray image registration, the proposed method performs significantly better than the two benchmark b-spline approaches (P < 0.001). The software implementation of the presented method and the data used in this study are made publicly available for scientific communities to use (http://www-o.ntust.edu.tw/∼cweiwang/ImprovedImageRegistration/). cweiwang@mail.ntust.edu.tw.

  8. A method of simultaneous no-screen X-ray film taking with direct twofold magnification of hands and feet

    International Nuclear Information System (INIS)

    Zajgner, J.; Szymanska-Prach, H.

    1978-01-01

    The authors propose an original method of X-ray examination of hands and feet which makes possible simultaneous radiography without screen and direct twofold magnified film taking. The method is not connected with the necessity of exposing the patient to an additional dose of X-rays. It has been tried in 20 patients with suspected rheumatoid arthritis. It requires an X-ray tube with 0.3 x 0.3 mm microfocus. (author)

  9. A NEW METHOD TO QUANTIFY X-RAY SUBSTRUCTURES IN CLUSTERS OF GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Andrade-Santos, Felipe; Lima Neto, Gastao B.; Lagana, Tatiana F. [Departamento de Astronomia, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Geofisica e Ciencias Atmosfericas, Rua do Matao 1226, Cidade Universitaria, 05508-090 Sao Paulo, SP (Brazil)

    2012-02-20

    We present a new method to quantify substructures in clusters of galaxies, based on the analysis of the intensity of structures. This analysis is done in a residual image that is the result of the subtraction of a surface brightness model, obtained by fitting a two-dimensional analytical model ({beta}-model or Sersic profile) with elliptical symmetry, from the X-ray image. Our method is applied to 34 clusters observed by the Chandra Space Telescope that are in the redshift range z in [0.02, 0.2] and have a signal-to-noise ratio (S/N) greater than 100. We present the calibration of the method and the relations between the substructure level with physical quantities, such as the mass, X-ray luminosity, temperature, and cluster redshift. We use our method to separate the clusters in two sub-samples of high- and low-substructure levels. We conclude, using Monte Carlo simulations, that the method recuperates very well the true amount of substructure for small angular core radii clusters (with respect to the whole image size) and good S/N observations. We find no evidence of correlation between the substructure level and physical properties of the clusters such as gas temperature, X-ray luminosity, and redshift; however, analysis suggest a trend between the substructure level and cluster mass. The scaling relations for the two sub-samples (high- and low-substructure level clusters) are different (they present an offset, i.e., given a fixed mass or temperature, low-substructure clusters tend to be more X-ray luminous), which is an important result for cosmological tests using the mass-luminosity relation to obtain the cluster mass function, since they rely on the assumption that clusters do not present different scaling relations according to their dynamical state.

  10. A method of measuring gold nanoparticle concentrations by x-ray fluorescence for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Wu Di; Li Yuhua; Wong, Molly D.; Liu Hong [Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2013-05-15

    Purpose: This paper reports a technique that enables the quantitative determination of the concentration of gold nanoparticles (GNPs) through the accurate detection of their fluorescence radiation in the diagnostic x-ray spectrum. Methods: Experimentally, x-ray fluorescence spectra of 1.9 and 15 nm GNP solutions are measured using an x-ray spectrometer, individually and within chicken breast tissue samples. An optimal combination of excitation and emission filters is determined to segregate the fluorescence spectra at 66.99 and 68.80 keV from the background scattering. A roadmap method is developed that subtracts the scattered radiation (acquired before the insertion of GNP solutions) from the signal radiation acquired after the GNP solutions are inserted. Results: The methods effectively minimize the background scattering in the spectrum measurements, showing linear relationships between GNP solutions from 0.1% to 10% weight concentration and from 0.1% to 1.0% weight concentration inside a chicken breast tissue sample. Conclusions: The investigation demonstrated the potential of imaging gold nanoparticles quantitatively in vivo for in-tissue studies, but future studies will be needed to investigate the ability to apply this method to clinical applications.

  11. Statistical methods applied to gamma-ray spectroscopy algorithms in nuclear security missions.

    Science.gov (United States)

    Fagan, Deborah K; Robinson, Sean M; Runkle, Robert C

    2012-10-01

    Gamma-ray spectroscopy is a critical research and development priority to a range of nuclear security missions, specifically the interdiction of special nuclear material involving the detection and identification of gamma-ray sources. We categorize existing methods by the statistical methods on which they rely and identify methods that have yet to be considered. Current methods estimate the effect of counting uncertainty but in many cases do not address larger sources of decision uncertainty, which may be significantly more complex. Thus, significantly improving algorithm performance may require greater coupling between the problem physics that drives data acquisition and statistical methods that analyze such data. Untapped statistical methods, such as Bayes Modeling Averaging and hierarchical and empirical Bayes methods, could reduce decision uncertainty by rigorously and comprehensively incorporating all sources of uncertainty. Application of such methods should further meet the needs of nuclear security missions by improving upon the existing numerical infrastructure for which these analyses have not been conducted. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Selection of polychlorinated plastics in plastic waste by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Kumasaki, H.; Shinozaki, Y.

    1979-01-01

    The X-ray fluorescence method using a small source of 55 Fe was examined and found to be applicable for the selection of polychlorinated plastics from plastic waste in model areas in Tokyo designated for investigating their content in the waste. The weight ratios of soft and hard polychlorinated plastics to the total plastic waste estimated by this method were found to be 15.6% and 0.29% respectively. These values agree well with the results obtained with the Beilstein method. (author)

  13. Generation of gamma-ray streaming kernels through cylindrical ducts via Monte Carlo method

    International Nuclear Information System (INIS)

    Kim, Dong Su

    1992-02-01

    Since radiation streaming through penetrations is often the critical consideration in protection against exposure of personnel in a nuclear facility, it has been of great concern in radiation shielding design and analysis. Several methods have been developed and applied to the analysis of the radiation streaming in the past such as ray analysis method, single scattering method, albedo method, and Monte Carlo method. But they may be used for order-of-magnitude calculations and where sufficient margin is available, except for the Monte Carlo method which is accurate but requires a lot of computing time. This study developed a Monte Carlo method and constructed a data library of solutions using the Monte Carlo method for radiation streaming through a straight cylindrical duct in concrete walls of a broad, mono-directional, monoenergetic gamma-ray beam of unit intensity. The solution named as plane streaming kernel is the average dose rate at duct outlet and was evaluated for 20 source energies from 0 to 10 MeV, 36 source incident angles from 0 to 70 degrees, 5 duct radii from 10 to 30 cm, and 16 wall thicknesses from 0 to 100 cm. It was demonstrated that average dose rate due to an isotropic point source at arbitrary positions can be well approximated using the plane streaming kernel with acceptable error. Thus, the library of the plane streaming kernels can be used for the accurate and efficient analysis of radiation streaming through a straight cylindrical duct in concrete walls due to arbitrary distributions of gamma-ray sources

  14. Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  15. X-ray microprobe analysis of platelets. Principles, methods and review of the literature.

    Science.gov (United States)

    Yarom, R

    1983-01-01

    Platelets are well suited to X-ray microanalysis as there is no need for chemical fixation or sectioning, and the concentrations of calcium and phosphorus are above 10(-3). The principles of the technique, the methods of specimen preparation, instrumental conditions during analysis and ways of quantitation are described. This is followed by a review of published reports and a brief summary of the author's own work in the field.

  16. New applications of elemental analysis methods using X-rays at the INPE Cyclotron

    International Nuclear Information System (INIS)

    Constantinescu, B.; Constantin, F.; Dima, S.; Plostinaru, D.; Popa-Simil, L.

    1990-01-01

    Some results in various samples elemental analysis using PIXE(Particle Induced X-ray Emission) method at INPE U-120 Cyclotron are presented. The main purpose of the research was the determination of metal concentration (Ca,Cr,Mn,Fe,Ni,Cu,Zn) in drug industry materials and products, some tree seeds as environmental pollution indicator, mineral oil and gasoline used in mechanical engineering, cooling water for oil industry equipment. (Author)

  17. Multiscale optical simulation settings: challenging applications handled with an iterative ray-tracing FDTD interface method.

    Science.gov (United States)

    Leiner, Claude; Nemitz, Wolfgang; Schweitzer, Susanne; Kuna, Ladislav; Wenzl, Franz P; Hartmann, Paul; Satzinger, Valentin; Sommer, Christian

    2016-03-20

    We show that with an appropriate combination of two optical simulation techniques-classical ray-tracing and the finite difference time domain method-an optical device containing multiple diffractive and refractive optical elements can be accurately simulated in an iterative simulation approach. We compare the simulation results with experimental measurements of the device to discuss the applicability and accuracy of our iterative simulation procedure.

  18. Methods for deconvoluting and interpreting complex gamma- and x-ray spectral regions

    International Nuclear Information System (INIS)

    Gunnink, R.

    1983-06-01

    Germanium and silicon detectors are now widely used for the detection and measurement of x and gamma radiation. However, some analysis situations and spectral regions have heretofore been too complex to deconvolute and interpret by techniques in general use. One example is the L x-ray spectrum of an element taken with a Ge or Si detector. This paper describes some new tools and methods that were developed to analyze complex spectral regions; they are illustrated with examples

  19. Determination of calcium and iron in limestone by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Sovtsova, M.K.

    1977-01-01

    The results of determining calcium and iron content in limestone by X-ray fluorescence method are described. The 109 Cd isotape was chosen as a source for excitation, as it permited to reduce the concentration degeneration in the range of large Ca contents due to the larger energy of the primary radiation. The root-mean-square deviation from the data of chemical analysis was +-0.02%FeO and +-0.22%CaO

  20. Angular quadrature sets for the streaming ray method in x-y geometry

    International Nuclear Information System (INIS)

    England, R.; Filippone, W.L.

    1983-01-01

    Steaming ray (SR) computations normally employ a set of specially selected ray directions. For x-y geometry, these directions are not uniformly spaced in the azimuthal angle, nor do they conform to any of the standard quadrature sets in current use. For simplicity in all previous SR computations, uniform angular weights were used. This note investigates two methods--a bisection scheme and a Fourier scheme--for selecting more appropriate azimuthal angular weights. In the bisection scheme, the azimuthal weight assigned to an SR direction is half the angular spread (in the x-y plane) between its two adjacent ray directions. In the Fourier method, the weights are chosen such that the number of terms in a Fourier series exactly integrable on the interval (0, 2π) is maximized. Several sample calculations have been performed. While both the Fourier and bisection weights showed significant advantage over the uniform weights used previously, the Fourier scheme appears to be the best method. Lists of bisection and Fourier weights are given for quadrature sets containing 4, 8, 12, ..., 60 azimuthal SR directions

  1. Alternative methods for ray tracing in uniaxial media. Application to negative refraction

    Science.gov (United States)

    Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

    2007-03-01

    In previous papers [C. Bellver-Cebreros, M. Rodriguez-Danta, Eikonal equation, alternative expression of Fresnel's equation and Mohr's construction in optical anisotropic media, Opt. Commun. 189 (2001) 193; C. Bellver-Cebreros, M. Rodriguez-Danta, Internal conical refraction in biaxial media and graphical plane constructions deduced from Mohr's method, Opt. Commun. 212 (2002) 199; C. Bellver-Cebreros, M. Rodriguez-Danta, Refraccion conica externa en medios biaxicos a partir de la construccion de Mohr, Opt. Pura AppliE 36 (2003) 33], the authors have developed a method based on the local properties of dielectric permittivity tensor and on Mohr's plane graphical construction in order to study the behaviour of locally plane light waves in anisotropic media. In this paper, this alternative methodology is compared with the traditional one, by emphasizing the simplicity of the former when studying ray propagation through uniaxial media (comparison is possible since, in this case, traditional construction becomes also plane). An original and simple graphical method is proposed in order to determine the direction of propagation given by the wave vector from the knowledge of the extraordinary ray direction (given by Poynting vector). Some properties of light rays in these media not described in the literature are obtained. Finally, two applications are considered: a description of optical birefringence under normal incidence and the study of negative refraction in uniaxial media.

  2. Development of X-ray and ion diagnostic methods for plasma focus research

    International Nuclear Information System (INIS)

    Sadowski, M.

    1986-12-01

    A review of experimental methods used for investigation of X-rays and ion-beams emmited from plasma focus facilities is presented. The research program has been realized at the Institute for Nuclear Studies in Swierk and at the Institut fuer Plasmaforschung in Stuttgart, within the frames of an international co-operation. The studies on ion emission from different PF facilities are reviewed. The application of CN-films with Al-filters and of different ion-pinhole cameras is described. The use of a Thomson mass-spectrometer adopted for plasma studies is presented. The time-resolved measurements combined with a simultaneous mass- and energy-analysis of the ion beams are also described. The most important results of these studies are summarized. Particular attention is also paid to the studies of the X-ray emission. The use of stereoscopic sets of vacuum pinhole cameras with thin Be-filters is described. The application of X-ray pinhole cameras equipped with miniature scintillators for time-resolved measurements is also presented. The most important results of the X-ray emission studies are summarized. 35 refs., 12 figs. (author)

  3. Assessment of a synchrotron X-ray method for quantitative analysis of calcium hydroxide

    International Nuclear Information System (INIS)

    Williams, P. Jason; Biernacki, Joseph J.; Bai Jianming; Rawn, Claudia J.

    2003-01-01

    Thermogravimetric analysis (TGA) and quantitative X-ray diffraction (QXRD) are widely used to determine the calcium hydroxide (CH) content in cementitious systems containing blends of Portland cement, fly ash, blast furnace slag, silica fume and other pozzolanic and hydraulic materials. These techniques, however, are destructive to cement samples and subject to various forms of error. While precise weight losses can be measured by TGA, extracting information from samples with multiple overlapping thermal events is difficult. And, however, while QXRD can offer easier deconvolution, the accuracy for components below about 5 wt.% is typically poor when a laboratory X-ray source is used. Furthermore, the destructive nature of both techniques prevents using them to study the in situ hydration of a single contiguous sample for kinetic analysis. In an attempt to overcome these problems, the present research evaluated the use of synchrotron X-rays for quantitative analysis of CH. A synchrotron X-ray source was used to develop calibration data for quantification of the amount of CH in mixtures with fly ash. These data were compared to conventional laboratory XRD data for like samples. While both methods were found to offer good quantification, synchrotron XRD (SXRD) provided a broader range of detectability and higher accuracy than laboratory diffraction and removed the subjectivity as compared to TGA analysis. Further, the sealed glass capillaries used with the synchrotron source provided a nondestructive closed, in situ environment for tracking hydrating specimens from zero to any desired age

  4. Solid-state x-ray receptor and method of making same

    International Nuclear Information System (INIS)

    Dorman, A.; Glave, W.K.; Birnbach, C.

    1985-01-01

    An X-ray receptor for producing electrical signals representative of an X-ray image is discussed. An array of semiconductor elements is mounted on at least one support, each element being formed of semiconductor material which is an element of Group 4A of the Periodic Table of Elements or a compound of such an element, or which is at least one element of Group 3A of the Periodic Table of Elements together with at least one element of Group 5A of the Periodic Table of Elements, and having at least one PN junction therein. The array is positioned to receive impinging X-rays and to produce electrical signals in response thereto. Electrical conducting leads are supported on the support, and the electrical signals which are produced by respective ones of the semiconductor elements are coupled to these electrical conducting leads. Output terminals also are supported on the support to provide output image signals; and circuitry including multiplexing circuits additionally is supported on the support for processing and multiplexing the electrical signals from the electrical conducting leads to the output terminals. Also disclosed is a method by which the X-ray receptor is made

  5. Exploring the potential of the cosmic-ray neutron method to measure interception storage dynamics

    Science.gov (United States)

    Jakobi, Jannis; Bogena, Heye; Huisman, Johan Alexander; Diekkrüger, Bernd; Vereecken, Harry

    2017-04-01

    Cosmic-ray neutron soil moisture probes are an emerging technology that relies on the negative correlation between near-surface fast neutron counts and soil moisture content. Hydrogen atoms in the soil, which are mainly present as water, moderate the secondary neutrons on the way back to the surface. Any application of this method needs to consider the sensitivity of the neutron counts to additional sources of hydrogen (e.g. above- and below-ground biomass, humidity of the lower atmosphere, lattice water of the soil minerals, organic matter and water in the litter layer, intercepted water in the canopy, and soil organic matter). In this study, we analyzed the effects of canopy-intercepted water on the cosmic-ray neutron counts. For this, an arable field cropped with sugar beet was instrumented with several cosmic-ray neutron probes and a wireless sensor network with more than 140 in-situ soil moisture sensors. Additionally rainfall interception was estimated using a new approach coupling throughfall measurements and leaf wetness sensors. The derived interception storage was used to correct for interception effects on cosmic ray neutrons to enhance soil water content prediction. Furthermore, the potential for a simultaneous prediction of above- and below-ground biomass, soil moisture and interception was tested.

  6. Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

    Science.gov (United States)

    Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

    2010-01-01

    An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

  7. Investigation of first ray mobility during gait by kinematic fluoroscopic imaging-a novel method

    Directory of Open Access Journals (Sweden)

    Martin Heiner

    2012-02-01

    Full Text Available Abstract Background It is often suggested that sagittal instability at the first tarso-metatarsal joint level is a primary factor for hallux valgus and that sagittal instability increases with the progression of the deformity. The assessment of the degree of vertical instability is usually made by clinical evaluation while any measurements mostly refer to a static assessment of medial ray mobility (i.e. the plantar/dorsal flexion in the sagittal plane. Testing methods currently available cannot attribute the degree of mobility to the corresponding anatomical joints making up the medial column of the foot. The aim of this study was to develop a technique which allows for a quantification of the in-vivo sagittal mobility of the joints of the medial foot column during the roll-over process under full weight bearing. Methods Mobility of first ray bones was investigated by dynamic distortion-free fluoroscopy (25 frames/s of 14 healthy volunteers and 8 patients with manifested clinical instability of the first ray. A CAD-based evaluation method allowed the determination of mobility and relative displacements and rotations of the first ray bones within the sagittal plane during the stance phase of gait. Results Total flexion of the first ray was found to be 13.63 (SD 6.14 mm with the healthy volunteers and 13.06 (SD 8.01 mm with the patients (resolution: 0.245 mm/pixel. The dorsiflexion angle was 5.27 (SD 2.34 degrees in the healthy volunteers and increased to 5.56 (SD 3.37 degrees in the patients. Maximum rotations were found at the naviculo-cuneiform joints and least at the first tarso-metatarsal joint level in both groups. Conclusions Dynamic fluoroscopic assessment has been shown to be a valuable tool for characterisation of the kinematics of the joints of the medial foot column during gait. A significant difference in first ray flexion and angular rotation between the patients and healthy volunteers however could not be found.

  8. Determinations of silicon and phosphorus in Pepperbush standard reference material by neutron activation and x-ray fluorescence methods

    International Nuclear Information System (INIS)

    Mizumoto, Yoshihiko; Nishio, Hirofumi; Hayashi, Takeshi; Kusakabe, Toshio; Iwata, Shiro.

    1987-01-01

    Silicon and phosphorus contents in Pepperbush standard reference material were determined by neutron activation and X-ray fluorescence methods. In neutron activation analysis, β-ray spectra of 32 P produced by 31 P(n,γ) 32 P reaction on Pepperbush and standard samples were measured by a low background β-ray spectrometer. In X-ray fluorescence analysis, the standard samples were prepared by mixing the Pepperbush powder with silicon dioxide and diammonium hydrogenphosphate. Characteristic X-rays from the samples were analyzed by a wavelength dispersive X-ray fluorescence spectrometer. From the β and X-ray intensities, silicon and phosphorus contents in Pepperbush were determined to be 1840 ± 80 and 1200 ± 50 μg g -1 , respectively. (author)

  9. Importance of X-ray diagnosis of colorectal polyps as compared to the endoscopic method

    International Nuclear Information System (INIS)

    Lass, B.

    1980-01-01

    The importance of X-ray diagnosis of colorectal polyps as compared with endoscopy is assessed on the basis of the literature and the authoress's own investigations. These make clean that the double contrast method attains a degree of accuracy approaching that of endoscopy. Some investigations by the authoress in 98 patients show that the procedure permits to recognize 72% of polyps under 1 cm of length and 81% above if the patients are well prepared. 4 out of 129 polyps were not detected by endoscopy. Coloscopy is not an infallible method. Both methods should not be viewed as rivalling but as complementary ones. Knowledge of the limitations and methods, and contant endeavour to combine all methods will entail the best diagnostic results. (orig.) [de

  10. Quantitative analysis of scaling error compensation methods in dimensional X-ray computed tomography

    DEFF Research Database (Denmark)

    Müller, P.; Hiller, Jochen; Dai, Y.

    2015-01-01

    X-ray Computed Tomography (CT) has become an important technology for quality control of industrial components. As with other technologies, e.g., tactile coordinate measurements or optical measurements, CT is influenced by numerous quantities which may have negative impact on the accuracy...... errors of the manipulator system (magnification axis). This article also introduces a new compensation method for scaling errors using a database of reference scaling factors and discusses its advantages and disadvantages. In total, three methods for the correction of scaling errors – using the CT ball...

  11. Hard X-ray nanoimaging method using local diffraction from metal wire

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hidekazu, E-mail: htakano@sci.u-hyogo.ac.jp; Konishi, Shigeki; Shimomura, Sho; Azuma, Hiroaki; Tsusaka, Yoshiyuki; Kagoshima, Yasushi [Center for Novel Material Science under Multi-Extreme Conditions, Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan)

    2014-01-13

    A simple hard X-ray imaging method achieving a high spatial resolution is proposed. Images are obtained by scanning a metal wire through the wave field to be measured and rotating the sample to collect data for back projection calculations; the local diffraction occurring at the edges of the metal wire operates as a narrow line probe. In-line holograms of a test sample were obtained with a spatial resolution of better than 100 nm. The potential high spatial resolution of this method is shown by calculations using diffraction theory.

  12. Study on method of characteristics based on cell modular ray tracing

    International Nuclear Information System (INIS)

    Tang Chuntao; Zhang Shaohong

    2009-01-01

    To address the issue of accurately solving neutron transport problem in complex geometry, method of characteristics (MOC) is studied in this paper, and a quite effective and memory saving cell modular ray tracing (CMRT) method is developed and related angle discretization and boundary condition handling issues are discussed. A CMRT based MOC code-PEACH is developed and tested against C5G7 MOX benchmark problem. Numerical results demonstrate that PEACH can give excellent accuracy for both k eff and pin power distribution for neutron transport problem. (authors)

  13. Long-term storage method for soft X-ray irradiated 'Hyuganatsu' pollen

    International Nuclear Information System (INIS)

    Yano, S.; Tanaka, M.; Ohara, N.

    2008-01-01

    The long-term storage conditions for 'Hyuganatsu ' pollen that had been irradiated with soft X-rays was examined. This study, was aimed at production of 'Tosa-buntan' without formation of nuclear fruit. 1. We evaluated the germination rate of pollen that had been irradiated with soft X-ray (500 or 1,000 Gy) and stored at 3 deg C, -20 deg C, and -40 deg C. The germination rate was the same as that of unirradiated pollen, even after storage for 1 year. Soft X-ray irradiation did not influence the storage attributes of pollen. 2. In unirradiated pollen and pollen that had been irradiated with soft X-ray (500 or 1,000 Gy), temperature conditions necessary for storing from 3 months to 1 year were -20 deg C or less, and pollen stored at -40 deg C had a higher germination rate after 1 year. 3. The germination rate was 1% or less in 4 months if silica gel was sealed into a gas barrier bag with 1,000 Gy-irradiated pollen at a rate of 10:1 (w/w). The ability to germinate was completely lost after 1 year in these conditions. 4. We evaluated the effect of sealing methods on 1,000 Gy-irradiated pollen stored at -20 deg C. There was no difference in germination rates among pollen stored in gas-barrier bags, vacuum-packaged pollen, and pollen stored with nitrogen in gas-barrier bags. Moreover, the germination rate of 750 Gy-irradiated pollen stored at -20 deg C decreased from 3 months onwards when pollen was stored with a free-oxygen absorber (Ageless ZP). 5. Pollen that was treated with acetone before or after soft X-ray irradiation (750 Gy) withstood long-term storage of 1 year. Long-term storage was possible if pollen was stored at -20 deg C, as is the case for rough pollen

  14. Standard test method for nondestructive assay of special nuclear material holdup using Gamma-Ray spectroscopic methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method describes gamma-ray methods used to nondestructively measure the quantity of 235U, or 239Pu remaining as holdup in nuclear facilities. Holdup occurs in all facilities where nuclear material is processed, in process equipment, in exhaust ventilation systems and in building walls and floors. 1.2 This test method includes information useful for management, planning, selection of equipment, consideration of interferences, measurement program definition, and the utilization of resources (1, 2, 3, 4). 1.3 The measurement of nuclear material hold up in process equipment requires a scientific knowledge of radiation sources and detectors, transmission of radiation, calibration, facility operations and error analysis. It is subject to the constraints of the facility, management, budget, and schedule; plus health and safety requirements; as well as the laws of physics. The measurement process includes defining measurement uncertainties and is sensitive to the form and distribution of the material...

  15. Separation method of heavy-ion particle image from gamma-ray mixed images using an imaging plate

    CERN Document Server

    Yamadera, A; Ohuchi, H; Nakamura, T; Fukumura, A

    1999-01-01

    We have developed a separation method of alpha-ray and gamma-ray images using the imaging plate (IP). The IP from which the first image was read out by an image reader was annealed at 50 deg. C for 2 h in a drying oven and the second image was read out by the image reader. It was found out that an annealing ratio, k, which is defined as a ratio of the photo-stimulated luminescence (PSL) density at the first measurement to that at the second measurement, was different for alpha rays and gamma rays. By subtracting the second image multiplied by a factor of k from the first image, the alpha-ray image was separated from the alpha and gamma-ray mixed images. This method was applied to identify the images of helium, carbon and neon particles of high energies using the heavy-ion medical accelerator, HIMAC. (author)

  16. Beryllium window flange for synchrotron radiation X-ray beamline fabricated by hot isostatic press method

    International Nuclear Information System (INIS)

    Asaoka, Seiji; Maezawa, Hideki; Nishida, Kiyotoshi; Sakamoto, Naoki.

    1995-01-01

    The synchrotron radiation experimental facilities in National Laboratory for High Energy Physics are the experimental facilities for joint utilization, that possess the positron storage ring of 2.5 GeV exclusively used for synchrotron radiation. Synchrotron radiation is led through a mainstay beam channel to the laboratory, and in the beam line of X-ray, it is used for experiment through the taking-out window made of beryllium. At this time, the function of the taking-out window is to shut off between the ultrahigh vacuum in the mainstay beam channel and the atmosphere, and to cut the low energy component of synchrotron radiation spectra. The experiment using X-ray is carried out mostly in the atmosphere. The design of the efficient cooling water channel which is compatible with the flange construction is important under the high thermal load of synchrotron radiation. The beryllium window flange for synchrotron radiation X-ray was made by HIP method, and the ultrahigh vacuum test, the high pressure water flow test and the actual machine test were carried out by heat cycle. The properties required for the window material, the requirement of the construction, the new development of HIP method, and the experiments for evaluating the manufactured beryllium window are described. (K.I.)

  17. Direct-coupled-ray method for design-oriented three-dimensional transport analysis

    International Nuclear Information System (INIS)

    Bucholz, J.A.; Poncelet, C.G.

    1977-01-01

    A fast three-dimensional design-oriented transport method has been developed for the solution of both neutron and gamma transport problems. It combines a nodal approach with analytic integral transport to achieve relative speed and accuracy. An analytic solution is obtained for the angular flux in each of the 14 directions defined by the six faces and eight corners of a cubic mesh block. The scheme used to accommodate high-order anisotropic scattering is based on the formulation of ray-to-ray scattering probabilities in an integral sense. A variable mesh approximation has also been introduced to provide greater flexibility. The details of a direct-coupled-ray (DCR) → P 1 conversion technique have been developed but not yet implemented. The DCR method, as implemented in the TRANS3 code, has been used in a number of liquid-metal fast breeder reactor shielding applications. These included a one-dimensional deep penetration configuration and one-, two-, and three dimensional representations of the lower axial shield of the Clinch River Breeder Reactor. Comparisons with ANISN and DOT-III solutions indicated good to excellent agreement in most situations

  18. A standardless method of quantitative ceramic analysis using X-ray powder diffraction

    International Nuclear Information System (INIS)

    Mazumdar, S.

    1999-01-01

    A new procedure using X-ray powder diffraction data for quantitative estimation of the crystalline as well as the amorphous phase in ceramics is described. Classification of the crystalline and amorphous X-ray scattering was achieved by comparison of the slopes at two successive points of the powder pattern at scattering angles at which the crystalline and amorphous phases superimpose. If the second slope exceeds the first by a stipulated value, the intensity is taken as crystalline; otherwise the scattering is considered as amorphous. Crystalline phase analysis is obtained by linear programming techniques using the concept that each observed X-ray diffraction peak has contributions from n component phases, the proportionate analysis of which is required. The method does not require the measurement of calibration data for use as an internal standard, but knowledge of the approximate crystal structure of each phase of interest in the mixture is necessary. The technique is also helpful in qualitative analysis because each suspected phase is characterized by the probability that it will be present when a reflection zone is considered in which the suspected crystalline phase could contribute. The amorphous phases are determined prior to the crystalline ones. The method is applied to ceramic materials and some results are presented. (orig.)

  19. A method for interpolating asymmetric peak shapes in multiplet γ-ray spectra

    International Nuclear Information System (INIS)

    Wang Siguang; Mao Yajun; Zhu Bo; Liang Yutie; Tang Peijia

    2009-01-01

    The peak shapes of γ-rays at various energies must be known before unfolding the multiplet spectra obtained by using semiconductor or scintillation detectors. Traditional methods describe isolated peaks with multi-parameter fitting functions, and assume that most of these parameters do not vary with energy because it is rare to find a spectrum with enough isolated peaks to constrain their dependence. We present an algorithm for interpolating the γ-ray profile at any intermediate energy given a pair of isolated γ-ray peaks from the spectrum under consideration. The algorithm is tested on experimental data and leads to a good agreement between the interpolated profile and the fitting function. This method is more accurate than the traditional approach, since all aspects of the peak shape are allowed to vary with energy. New definitions of Left-Half Width at Half Maximum, and Right-Half Width at Half Maximum for peak shape description are introduced in this paper. (authors)

  20. Non-destructive investigations of Swiss museums objects with neutron and x-ray imaging methods

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Deschler, E.; Pernet, L.; Vontobel, P.

    2004-01-01

    Many objects of archaeological relevance found in Switzerland are from the Celtic and Roman era. Because of their uniqueness in most cases it is demanded to perform any investigation with such samples non-destructively. Depending on the structure and size of the objects a transmission experiment performed either with X-ray or neutron can alight inner structures, composition, defects or the principles of the manufacturing procedures. Furthermore, the treatment by conservators and restaurateurs becomes visible in many cases. This report describes some examples of such investigations. In the case of neutron investigations, beside the transmission imaging as a radiograph the three-dimensional structure was observed with a tomography technique. For X-ray radiography, the images were obtained in the same digital format because the similar experimental method (imaging plates) was applied. It becomes evident in the described examples that the combination and complementary use of both methods (neutrons and X-ray) brings insights in different aspects of the samples properties and treatment. This approach to study museums objects stored and exhibit in Switzerland can be extrapolated to other countries where these techniques are also simultaneously available in order to investigate other objects of relevance. The European network COST-G8 entitled 'Non-destructive analysis and testing of museum objects' can help to support initiatives in this direction. (author)

  1. Novel methods for measuring afterglow in developmental scintillators for X-ray and neutron detection

    Science.gov (United States)

    Bartle, C. M.; Edgar, A.; Dixie, L.; Varoy, C.; Piltz, R.; Buchanan, S.; Rutherford, K.

    2011-09-01

    In this paper we discuss two novel methods of measuring afterglow in scintillators. One method is designed for X-ray detection and the other for neutron detection applications. In the first method a commercial fan-beam scanner of basic design similar to those seen at airports is used to deliver a typically 12 ms long X-ray pulse to a scintillator by passing the test equipment through the scanner on the conveyor belt. In the second method the thermal neutron beam from a research reactor is incident on the scintillator. The beam is cut-off in about 1 ms using a 10B impregnated aluminum pneumatic shutter, and the afterglow is recorded on a dual range storage oscilloscope to capture both the steady state intensity and the weak decay. We describe these measurement methods and the results obtained for a range of developmental ceramic and glass scintillators, as well as some standard scintillators such as NaI(Tl), LiI(Eu) and the plastic scintillator NE102A. Preliminary modeling of the afterglow is presented.

  2. Novel methods for measuring afterglow in developmental scintillators for X-ray and neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Bartle, C.M., E-mail: m.bartle@gns.cri.nz [National Isotope Centre, GNS Science, PO Box 31312, Lower Hutt 5040 (New Zealand); Edgar, A.; Dixie, L.; Varoy, C. [School of Chemistry and Physics, Victoria University of Wellington, Wellington 6140 (New Zealand); Piltz, R. [Bragg Institute, ANSTO, PMB 1, Menai NSW 2234 (Australia); Buchanan, S.; Rutherford, K. [School of Chemistry and Physics, Victoria University of Wellington, Wellington 6140 (New Zealand)

    2011-09-21

    In this paper we discuss two novel methods of measuring afterglow in scintillators. One method is designed for X-ray detection and the other for neutron detection applications. In the first method a commercial fan-beam scanner of basic design similar to those seen at airports is used to deliver a typically 12 ms long X-ray pulse to a scintillator by passing the test equipment through the scanner on the conveyor belt. In the second method the thermal neutron beam from a research reactor is incident on the scintillator. The beam is cut-off in about 1 ms using a {sup 10}B impregnated aluminum pneumatic shutter, and the afterglow is recorded on a dual range storage oscilloscope to capture both the steady state intensity and the weak decay. We describe these measurement methods and the results obtained for a range of developmental ceramic and glass scintillators, as well as some standard scintillators such as NaI(Tl), LiI(Eu) and the plastic scintillator NE102A. Preliminary modeling of the afterglow is presented.

  3. Finite difference method calculations of X-ray absorption fine structure for copper

    Energy Technology Data Exchange (ETDEWEB)

    Bourke, J.D. [School of Physics, University of Melbourne, Parkville, Vic 3010 (Australia); Chantler, C.T. [School of Physics, University of Melbourne, Parkville, Vic 3010 (Australia)]. E-mail: chantler@physics.unimelb.edu.au; Witte, C. [School of Physics, University of Melbourne, Parkville, Vic 3010 (Australia)

    2007-01-15

    The finite difference method is extended to calculate X-ray absorption fine structure (XAFS) for solid state copper. These extensions include the incorporation of a Monte Carlo frozen phonon technique to simulate the effect of thermal vibrations under a correlated Debye-Waller model, and the inclusion of broadening effects from inelastic processes. Spectra are obtained over an energy range in excess of 300 eV above the K absorption edge-more than twice the greatest energy range previously reported for a solid state calculation using this method. We find this method is highly sensitive to values of the photoelectron inelastic mean free path, allowing us to probe the accuracy of current models of this parameter, particularly at low energies. We therefore find that experimental data for the photoelectron inelastic mean free path can be obtained by this method. Our results compare favourably with high precision measurements of the X-ray mass attenuation coefficient for copper, reaching agreement to within 3%, and improving previous results using the finite difference method by an order of magnitude.

  4. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhang, Kai [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhu, Peiping; Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China and Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-02-15

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

  5. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

    2015-01-01

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations

  6. Correction method and software for image distortion and nonuniform response in charge-coupled device-based x-ray detectors utilizing x-ray image intensifier

    International Nuclear Information System (INIS)

    Ito, Kazuki; Kamikubo, Hironari; Yagi, Naoto; Amemiya, Yoshiyuki

    2005-01-01

    An on-site method of correcting the image distortion and nonuniform response of a charge-coupled device (CCD)-based X-ray detector was developed using the response of the imaging plate as a reference. The CCD-based X-ray detector consists of a beryllium-windowed X-ray image intensifier (Be-XRII) and a CCD as the image sensor. An image distortion of 29% was improved to less than 1% after the correction. In the correction of nonuniform response due to image distortion, subpixel approximation was performed for the redistribution of pixel values. The optimal number of subpixels was also discussed. In an experiment with polystyrene (PS) latex, it was verified that the correction of both image distortion and nonuniform response worked properly. The correction for the 'contrast reduction' problem was also demonstrated for an isotropic X-ray scattering pattern from the PS latex. (author)

  7. Expanded image database of pistachio x-ray images and classification by conventional methods

    Science.gov (United States)

    Keagy, Pamela M.; Schatzki, Thomas F.; Le, Lan Chau; Casasent, David P.; Weber, David

    1996-12-01

    In order to develop sorting methods for insect damaged pistachio nuts, a large data set of pistachio x-ray images (6,759 nuts) was created. Both film and linescan sensor images were acquired, nuts dissected and internal conditions coded using the U.S. Grade standards and definitions for pistachios. A subset of 1199 good and 686 insect damaged nuts was used to calculate and test discriminant functions. Statistical parameters of image histograms were evaluated for inclusion by forward stepwise discrimination. Using three variables in the discriminant function, 89% of test set nuts were correctly identified. Comparable data for 6 human subjects ranged from 67 to 92%. If the loss of good nuts is held to 1% by requiring a high probability to discard a nut as insect damaged, approximately half of the insect damage present in clean pistachio nuts may be detected and removed by x-ray inspection.

  8. Application of X-ray methods to assess grain vulnerability to damage resulting from multiple loads

    International Nuclear Information System (INIS)

    Zlobecki, A.

    1995-01-01

    The aim of the work is to describe wheat grain behavior under multiple dynamic loads with various multipliers. The experiments were conducted on Almari variety grain. Grain moisture was 11, 16, 21 and 28%. A special ram stand was used for loading the grain. The experiments were carried out using an 8 g weight, equivalent to impact energy of 4,6 x 10 -3 [J]. The X-ray method was used to assess damage. The exposure time was 8 minutes with X-ray lamp voltage equal to 15 kV. The position index was used as the measure of the damage. The investigation results were elaborated statistically. Based on the results of analysis of variance, regression analysis, the d-Duncan test and the Kolmogorov-Smirnov test, the damage number was shown to depend greatly on the number of impacts for the whole range of moisture of the grain loaded. (author)

  9. Comparison of matrix method and ray tracing in the study of complex optical systems

    Science.gov (United States)

    Anterrieu, Eric; Perez, Jose-Philippe

    2000-06-01

    In the context of the classical study of optical systems within the geometrical Gauss approximation, the cardinal elements are efficiently obtained with the aid of the transfer matrix between the input and output planes of the system. In order to take into account the geometrical aberrations, a ray tracing approach, using the Snell- Descartes laws, has been implemented in an interactive software. Both methods are applied for measuring the correction to be done to a human eye suffering from ametropia. This software may be used by optometrists and ophthalmologists for solving the problems encountered when considering this pathology. The ray tracing approach gives a significant improvement and could be very helpful for a better understanding of an eventual surgical act.

  10. Guideline of Monte Carlo calculation. Neutron/gamma ray transport simulation by Monte Carlo method

    CERN Document Server

    2002-01-01

    This report condenses basic theories and advanced applications of neutron/gamma ray transport calculations in many fields of nuclear energy research. Chapters 1 through 5 treat historical progress of Monte Carlo methods, general issues of variance reduction technique, cross section libraries used in continuous energy Monte Carlo codes. In chapter 6, the following issues are discussed: fusion benchmark experiments, design of ITER, experiment analyses of fast critical assembly, core analyses of JMTR, simulation of pulsed neutron experiment, core analyses of HTTR, duct streaming calculations, bulk shielding calculations, neutron/gamma ray transport calculations of the Hiroshima atomic bomb. Chapters 8 and 9 treat function enhancements of MCNP and MVP codes, and a parallel processing of Monte Carlo calculation, respectively. An important references are attached at the end of this report.

  11. A simple method to improve the quantification accuracy of energy-dispersive X-ray microanalysis

    International Nuclear Information System (INIS)

    Walther, T

    2008-01-01

    Energy-dispersive X-ray spectroscopy in a transmission electron microscope is a standard tool for chemical microanalysis and routinely provides qualitative information on the presence of all major elements above Z=5 (boron) in a sample. Spectrum quantification relies on suitable corrections for absorption and fluorescence, in particular for thick samples and soft X-rays. A brief presentation is given of an easy way to improve quantification accuracy by evaluating the intensity ratio of two measurements acquired at different detector take-off angles. As the take-off angle determines the effective sample thickness seen by the detector this method corresponds to taking two measurements from the same position at two different thicknesses, which allows to correct absorption and fluorescence more reliably. An analytical solution for determining the depth of a feature embedded in the specimen foil is also provided.

  12. Abstracts of the 8th Conference on total reflection x-ray fluorescence analysis and related methods

    International Nuclear Information System (INIS)

    Wobrauschek, P.

    2000-01-01

    The 8. conference on total reflection x-ray fluorescence analysis and related methods held from 25.9 to 29.9.2000 contains 79 abstracts about x-ray fluorescence analysis (XRFA) as a powerful tool used for industrial production, geological prospecting and for environmental control. Total reflection x-ray fluorescence spectroscopy is also a tool used for chemical analysis in medicine, industry and research. (E.B.)

  13. Improvement of the detector resolution in X-ray spectrometry by using the maximum entropy method

    International Nuclear Information System (INIS)

    Fernández, Jorge E.; Scot, Viviana; Giulio, Eugenio Di; Sabbatucci, Lorenzo

    2015-01-01

    In every X-ray spectroscopy measurement the influence of the detection system causes loss of information. Different mechanisms contribute to form the so-called detector response function (DRF): the detector efficiency, the escape of photons as a consequence of photoelectric or scattering interactions, the spectrum smearing due to the energy resolution, and, in solid states detectors (SSD), the charge collection artifacts. To recover the original spectrum, it is necessary to remove the detector influence by solving the so-called inverse problem. The maximum entropy unfolding technique solves this problem by imposing a set of constraints, taking advantage of the known a priori information and preserving the positive-defined character of the X-ray spectrum. This method has been included in the tool UMESTRAT (Unfolding Maximum Entropy STRATegy), which adopts a semi-automatic strategy to solve the unfolding problem based on a suitable combination of the codes MAXED and GRAVEL, developed at PTB. In the past UMESTRAT proved the capability to resolve characteristic peaks which were revealed as overlapped by a Si SSD, giving good qualitative results. In order to obtain quantitative results, UMESTRAT has been modified to include the additional constraint of the total number of photons of the spectrum, which can be easily determined by inverting the diagonal efficiency matrix. The features of the improved code are illustrated with some examples of unfolding from three commonly used SSD like Si, Ge, and CdTe. The quantitative unfolding can be considered as a software improvement of the detector resolution. - Highlights: • Radiation detection introduces distortions in X- and Gamma-ray spectrum measurements. • UMESTRAT is a graphical tool to unfold X- and Gamma-ray spectra. • UMESTRAT uses the maximum entropy method. • UMESTRAT’s new version produces unfolded spectra with quantitative meaning. • UMESTRAT is a software tool to improve the detector resolution.

  14. Determination of γ-rays emitting radionuclides in surface water: application of a quantitative biosensing method

    International Nuclear Information System (INIS)

    Wolterbeek, H. Th.; Van der Meer, A. J. G. M.

    1995-01-01

    A quantitative biosensing method has been developed for the determination of γ-rays emitting radionuclides in surface water. The method is based on the concept that at equilibrium the specific radioactivity in the biosensor is equal to the specific radioactivity in water. The method consists of the measurement of both the radionuclide and the related stable isotope (element) in the biosensor and the determination of the element in water. This three-way analysis eliminates problems such as unpredictable biosensor behaviour, effects of water elemental composition or further abiotic parameters on accumulation levels: what remains is the generally high enrichment (bioaccumulation factor BCF) of elements and radionuclides in the biosensor material. Using water plants, the method is shown to be three to five orders of magnitude more sensitive than the direct analysis of water. (author)

  15. Determination of {gamma}-rays emitting radionuclides in surface water: application of a quantitative biosensing method

    Energy Technology Data Exchange (ETDEWEB)

    Wolterbeek, H Th; Van der Meer, A. J. G. M. [Delft University of Technology, Interfaculty Reactor Institute, Mekelweg 15, 2629 JB Delft (Netherlands)

    1995-12-01

    A quantitative biosensing method has been developed for the determination of {gamma}-rays emitting radionuclides in surface water. The method is based on the concept that at equilibrium the specific radioactivity in the biosensor is equal to the specific radioactivity in water. The method consists of the measurement of both the radionuclide and the related stable isotope (element) in the biosensor and the determination of the element in water. This three-way analysis eliminates problems such as unpredictable biosensor behaviour, effects of water elemental composition or further abiotic parameters on accumulation levels: what remains is the generally high enrichment (bioaccumulation factor BCF) of elements and radionuclides in the biosensor material. Using water plants, the method is shown to be three to five orders of magnitude more sensitive than the direct analysis of water. (author)

  16. Discrimination methods between neutron and gamma rays for boron loaded plastic scintillators

    CERN Document Server

    Normand, S; Haan, S; Louvel, M

    2002-01-01

    Boron loaded plastic scintillators exhibit interesting properties for neutron detection in nuclear waste management and especially in investigating the amount of fissile materials when enclosed in waste containers. Combining a high thermal neutron efficiency and a low mean neutron lifetime, they are suitable in neutron multiplicity counting. However, due to their high sensitivity to gamma rays, pulse shape discrimination methods need to be developed in order to optimize the passive neutron assay measurement. From the knowledge of their physical properties, it is possible to separate the three kinds of particles that have interacted in the boron loaded plastic scintillator (gamma, fast neutron and thermal neutron). For this purpose, we have developed and compared the two well known discrimination methods (zero crossing and charge comparison) applied for the first time to boron loaded plastic scintillator. The setup for the zero crossing discrimination method and the charge comparison methods is thoroughly expl...

  17. A new method for the reconstruction of very-high-energy gamma-ray spectra and application to galatic cosmic-ray accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Milton Virgilio

    2014-09-15

    In this thesis, high-energy (HE; E>0.1 GeV) and very-high-energy (VHE; E>0.1 TeV) γ-ray data were investigated to probe Galactic stellar clusters (SCs) and star-forming regions (SFRs) as sites of hadronic Galactic cosmic-ray (GCR) acceleration. In principle, massive SCs and SFRs could accelerate GCRs at the shock front of the collective SC wind fed by the individual high-mass stars. The subsequently produced VHE γ rays would be measured with imaging air-Cherenkov telescopes (IACTs). A couple of the Galactic VHE γ-ray sources, including those potentially produced by SCs, fill a large fraction of the field-of-view (FoV) and require additional observations of source-free regions to determine the dominant background for a spectral reconstruction. A new method of reconstructing spectra for such extended sources without the need of further observations is developed: the Template Background Spectrum (TBS). This methods is based on a method to generate skymaps, which determines background in parameter space. The idea is the creation of a look-up of the background normalisation in energy, zenith angle, and angular separation and to account for possible systematics. The results obtained with TBS and state-of-the-art background-estimation methods on H.E.S.S. data are in good agreement. With TBS even those sources could be reconstructed that normally would need further observations. Therefore, TBS is the third method to reconstruct VHE γ-ray spectra, but the first one to not need additional observations in the analysis of extended sources. The discovery of the largest VHE γ-ray source HESSJ1646-458 (2.2 in size) towards the SC Westerlund 1 (Wd1) can be plausibly explained by the SC-wind scenario. But owing to its size, other alternative counterparts to the TeV emission (pulsar, binary system, magnetar) were found in the FoV. Therefore, an association of HESSJ1646-458 with the SC is favoured, but cannot be confirmed. The SC Pismis 22 is located in the centre of the

  18. A new method for the reconstruction of very-high-energy gamma-ray spectra and application to galatic cosmic-ray accelerators

    International Nuclear Information System (INIS)

    Fernandes, Milton Virgilio

    2014-09-01

    In this thesis, high-energy (HE; E>0.1 GeV) and very-high-energy (VHE; E>0.1 TeV) γ-ray data were investigated to probe Galactic stellar clusters (SCs) and star-forming regions (SFRs) as sites of hadronic Galactic cosmic-ray (GCR) acceleration. In principle, massive SCs and SFRs could accelerate GCRs at the shock front of the collective SC wind fed by the individual high-mass stars. The subsequently produced VHE γ rays would be measured with imaging air-Cherenkov telescopes (IACTs). A couple of the Galactic VHE γ-ray sources, including those potentially produced by SCs, fill a large fraction of the field-of-view (FoV) and require additional observations of source-free regions to determine the dominant background for a spectral reconstruction. A new method of reconstructing spectra for such extended sources without the need of further observations is developed: the Template Background Spectrum (TBS). This methods is based on a method to generate skymaps, which determines background in parameter space. The idea is the creation of a look-up of the background normalisation in energy, zenith angle, and angular separation and to account for possible systematics. The results obtained with TBS and state-of-the-art background-estimation methods on H.E.S.S. data are in good agreement. With TBS even those sources could be reconstructed that normally would need further observations. Therefore, TBS is the third method to reconstruct VHE γ-ray spectra, but the first one to not need additional observations in the analysis of extended sources. The discovery of the largest VHE γ-ray source HESSJ1646-458 (2.2 in size) towards the SC Westerlund 1 (Wd1) can be plausibly explained by the SC-wind scenario. But owing to its size, other alternative counterparts to the TeV emission (pulsar, binary system, magnetar) were found in the FoV. Therefore, an association of HESSJ1646-458 with the SC is favoured, but cannot be confirmed. The SC Pismis 22 is located in the centre of the

  19. A fully Bayesian method for jointly fitting instrumental calibration and X-ray spectral models

    International Nuclear Information System (INIS)

    Xu, Jin; Yu, Yaming; Van Dyk, David A.; Kashyap, Vinay L.; Siemiginowska, Aneta; Drake, Jeremy; Ratzlaff, Pete; Connors, Alanna; Meng, Xiao-Li

    2014-01-01

    Owing to a lack of robust principled methods, systematic instrumental uncertainties have generally been ignored in astrophysical data analysis despite wide recognition of the importance of including them. Ignoring calibration uncertainty can cause bias in the estimation of source model parameters and can lead to underestimation of the variance of these estimates. We previously introduced a pragmatic Bayesian method to address this problem. The method is 'pragmatic' in that it introduced an ad hoc technique that simplified computation by neglecting the potential information in the data for narrowing the uncertainty for the calibration product. Following that work, we use a principal component analysis to efficiently represent the uncertainty of the effective area of an X-ray (or γ-ray) telescope. Here, however, we leverage this representation to enable a principled, fully Bayesian method that coherently accounts for the calibration uncertainty in high-energy spectral analysis. In this setting, the method is compared with standard analysis techniques and the pragmatic Bayesian method. The advantage of the fully Bayesian method is that it allows the data to provide information not only for estimation of the source parameters but also for the calibration product—here the effective area, conditional on the adopted spectral model. In this way, it can yield more accurate and efficient estimates of the source parameters along with valid estimates of their uncertainty. Provided that the source spectrum can be accurately described by a parameterized model, this method allows rigorous inference about the effective area by quantifying which possible curves are most consistent with the data.

  20. New X-ray testing methods of aerosol products for industrial radiography

    Energy Technology Data Exchange (ETDEWEB)

    Bozydar Knyziak, Adrian, E-mail: a.knyziak@gum.gov.pl; Rzodkiewicz, Witold, E-mail: w.rzodkiewicz@gum.gov.pl; Kaczorowska, Ewa, E-mail: e.kaczorowska@gum.gov.pl; Derlacinski, Michal, E-mail: m.derlacinski@gum.gov.pl

    2017-02-01

    An amount of product in e.g. an aerosol canister is not difficult to estimate by weighing a filled can and subtracting the tare of packaging. In this way, we can obtain the net weight of the ingredients present in the can. Although, this does not indicate the volumetric content. Therefore, in the paper, the fundamental (the weight method and given by FEICA) and new methods (given by authors) related to the determination of the volumetric content of canister filled with aeorosol products are presented. The new methods are based on direct digital radiography (DR) using X-ray radiation. For the needs of new methods, the X-ray CCD-DR imaging system was built and developed in our Laboratory in Department of Radiation and Vibration at the Central Office of Measures. For comparison purposes, with regard to the volumetric content, a lot of metal cans of capacities 140, 185, 450, 700 ml were inspected. In future, computed tomography (CT) for industrial radiography in our laboratory will be used. Currently, an algorithm for CT is being tested. It will give us possibility for very precise measurements to determine volumetric content of examined canisters.

  1. Gamma-Ray Attenuation to Evaluate Soil Porosity: An Analysis of Methods

    Science.gov (United States)

    Pires, Luiz F.; Pereira, André B.

    2014-01-01

    Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations of ϕ are necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluate ϕ were analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determine ϕ. The results obtained point out a good correlation between both methods. However, when ϕ is obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one. PMID:24616640

  2. Development of fitting methods using geometric progression formulae of gamma-ray buildup factors

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka

    2006-01-01

    The gamma ray buildup factors are represented by an approximation method to speed up calculation using the point attenuation kernel method. The fitting parameters obtained by the GP formula and Taylor's formula are compiled in ANSI/ANS 6.4.3, available without any limitation. The GP formula featured high accuracy but required a high-level fitting technique. Thus the GP formula was divided into a curved line and a part representing the base values and used to develop the a fitting method and X k fitting method. As a result, this methodology showed that (1) when the fitting ranges were identical, there was no change in standard deviation when the unit penetration depth was varied; (2) even with fitting up to 300 mfp, the average standard deviation of 26 materials was 2.9% and acceptable GP parameters were extracted; (3) when the same end points of the fitting were selected and the starting points of fitting were identical with the unit penetration depth, the deviation became smaller with increasing unit penetration depth; and (4) even with the deviation adjusted to the positive side from 0.5 mfp to 300 mfp, the average standard deviation of 26 materials was 5.6%, which was an acceptable value. However, the GP parameters obtained by this methodology cannot be used for direct interpolation using gamma ray energy or materials. (author)

  3. The x-ray time of flight method for investigation of ghosting in amorphous selenium-based flat panel medical x-ray imagers

    International Nuclear Information System (INIS)

    Rau, A.W.; Bakueva, L.; Rowlands, J.A.

    2005-01-01

    Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristics of FPIs can be affected by ghosting (i.e., radiation-induced changes of sensitivity) when the dose to the detector is high (e.g., portal imaging and mammography) or the images are acquired at a high frame rate (e.g., fluoroscopy). In this paper, the x-ray time-of-flight (TOF) method is introduced as a tool for the investigation of ghosting in a-Se photoconductor layers. The method consists of irradiating layers of a-Se with short x-ray pulses. From the current generated in the a-Se layer, ghosting is quantified and the ghosting parameters (charge carrier generation rate and carrier lifetimes and mobilities) are assessed. The x-ray TOF method is novel in that (1) x-ray sensitivity (S) and ghosting parameters can be measured simultaneously (2) the transport of both holes and electrons can be isolated, and (3) the method is applicable to the practical a-Se layer structure with blocking contacts used in FPIs. The x-ray TOF method was applied to an analysis of ghosting in a-Se photoconductor layers under portal imaging conditions, i.e., 1 mm thick a-Se layers, biased at 5 V/μm, were irradiated using a 6 MV LINAC x-ray beam to a total dose (ghosting dose) of 30 Gy. The initial sensitivity (S 0 ) of the a-Se layers was 63±2 nC cm -2 cGy -1 . It was found that S decreases to 30% of S 0 after a ghosting dose of 5 Gy and to 21% after 30 Gy at which point no further change in S occurs. At an x-ray intensity of 22 Gy/s (instantaneous dose rate during a LINAC x-ray pulse), the charge carrier generation rate was 1.25±0.1x10 22 ehp m -3 s -1 and, to a first approximation, independent of the ghosting dose. However, both hole and electron transport showed a

  4. X-ray imaging with monochromatic synchrotron radiation. Fluorescent and phase-contrast method

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

    2002-05-01

    To obtain the high sensitive x-ray images of biomedical object, new x-ray imaging techniques using fluorescent x-ray and phase-contrast x-ray are being developed in Japan. Fluorescent x-ray CT can detect very small amounts of specific elements in the order of ppm at one pixel, whereas phase-contrast x-ray imaging with interferometer can detect minute differences of biological object. Here, our recent experimental results are presented. (author)

  5. Development and exploitation of the slit method for the characterization of x-ray screen-film combinations

    International Nuclear Information System (INIS)

    Hoeschen, D.

    1987-01-01

    For the determination of the modulation transfer function (MTF) of screen-film combinations which are used in medical x-ray diagnostics a measuring method has been developed: the screen-film combination is exposed to x-rays behind a thin slit and the modulation transfer function is calculated from the resulting rather broad slit images on the film. After solving many technical and photographic problems, the slit method provides high precision in the MTF determination. The only objection against this method is the necessary high dose variation which has to be provided by the x-ray machine

  6. Experimental validation of a multi-energy x-ray adapted scatter separation method

    Science.gov (United States)

    Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.

    2016-12-01

    Both in radiography and computed tomography (CT), recently emerged energy-resolved x-ray photon counting detectors enable the identification and quantification of individual materials comprising the inspected object. However, the approaches used for these operations require highly accurate x-ray images. The accuracy of the images is severely compromised by the presence of scattered radiation, which leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in CT. The aim of the present study was to experimentally evaluate a recently introduced partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. For this purpose, a prototype x-ray system was used. Several radiographic acquisitions of an anthropomorphic thorax phantom were performed. Reference primary images were obtained via the beam-stop (BS) approach. The attenuation images acquired from PASSSA-corrected data showed a substantial increase in local contrast and internal structure contour visibility when compared to uncorrected images. A substantial reduction of scatter induced bias was also achieved. Quantitatively, the developed method proved to be in relatively good agreement with the BS data. The application of the proposed scatter correction technique lowered the initial normalized root-mean-square error (NRMSE) of 45% between the uncorrected total and the reference primary spectral images by a factor of 9, thus reducing it to around 5%.

  7. Spectrum unfolding in X-ray spectrometry using the maximum entropy method

    International Nuclear Information System (INIS)

    Fernandez, Jorge E.; Scot, Viviana; Di Giulio, Eugenio

    2014-01-01

    The solution of the unfolding problem is an ever-present issue in X-ray spectrometry. The maximum entropy technique solves this problem by taking advantage of some known a priori physical information and by ensuring an outcome with only positive values. This method is implemented in MAXED (MAXimum Entropy Deconvolution), a software code contained in the package UMG (Unfolding with MAXED and GRAVEL) developed at PTB and distributed by NEA Data Bank. This package contains also the code GRAVEL (used to estimate the precision of the solution). This article introduces the new code UMESTRAT (Unfolding Maximum Entropy STRATegy) which applies a semi-automatic strategy to solve the unfolding problem by using a suitable combination of MAXED and GRAVEL for applications in X-ray spectrometry. Some examples of the use of UMESTRAT are shown, demonstrating its capability to remove detector artifacts from the measured spectrum consistently with the model used for the detector response function (DRF). - Highlights: ► A new strategy to solve the unfolding problem in X-ray spectrometry is presented. ► The presented strategy uses a suitable combination of the codes MAXED and GRAVEL. ► The applied strategy provides additional information on the Detector Response Function. ► The code UMESTRAT is developed to apply this new strategy in a semi-automatic mode

  8. A method to unfold the efficiency of gaseous detectors exposed to broad X-ray spectra

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Souza, Maria Ines S. de; Lopes, Ricardo T.

    2000-01-01

    A method to obtain the efficiency of a gaseous detector exposed to broad energy X-ray spectra was developed. It consists in the de-convolution of the integrated detector response using the shapes of those spectra as a tool to unfold the aimed detector efficiency curve. For this purpose, the spectra emitted by a X-ray tube under several anode voltages, were properly characterized through measurements with a NaI(Tl) spectrometer. A Lorentz function was then fitted to each of the spectra, and their parameters expressed as a function of the anode voltage, by using polynomial and gaussian fittings. The integral of the product of each Lorentz function, by another unknown Lorentz function, expressing the detector efficiency curve, represents the response of the detector for each anode tension, e.g., each X-ray spectrum. The symbolical integration of that product, produces a general function containing the unknown parameters of the unknown efficiency curve. A non-linear fitting of this general function, to the detector response points, as experimentally obtained, generates the aimed parameters for the efficiency curve. The final detector efficiency curve is obtained after normalization procedures. (author)

  9. Advanced simulations of x-ray beam propagation through CRL transfocators using ray-tracing and wavefront propagation methods

    DEFF Research Database (Denmark)

    Baltser, Jana; Bergbäck Knudsen, Erik; Vickery, Anette

    2011-01-01

    Compound refractive lenses (CRL) are widely used to manipulate synchrotron radiation beams. Accurate modelling of X-ray beam propagation through individual lenses and through "transfocators" composed of a large number of CRLs is of high importance, since it allows for comprehensive optimization...

  10. Injection Methods and Instrumentation for Serial X-ray Free Electron Laser Experiments

    Science.gov (United States)

    James, Daniel

    Scientists have used X-rays to study biological molecules for nearly a century. Now with the X-ray free electron laser (XFEL), new methods have been developed to advance structural biology. These new methods include serial femtosecond crystallography, single particle imaging, solution scattering, and time resolved techniques. The XFEL is characterized by high intensity pulses, which are only about 50 femtoseconds in duration. The intensity allows for scattering from microscopic particles, while the short pulses offer a way to outrun radiation damage. XFELs are powerful enough to obliterate most samples in a single pulse. While this allows for a "diffract and destroy" methodology, it also requires instrumentation that can position microscopic particles into the X-ray beam (which may also be microscopic), continuously renew the sample after each pulse, and maintain sample viability during data collection. Typically these experiments have used liquid microjets to continuously renew sample. The high flow rate associated with liquid microjets requires large amounts of sample, most of which runs to waste between pulses. An injector designed to stream a viscous gel-like material called lipidic cubic phase (LCP) was developed to address this problem. LCP, commonly used as a growth medium for membrane protein crystals, lends itself to low flow rate jetting and so reduces the amount of sample wasted significantly. This work discusses sample delivery and injection for XFEL experiments. It reviews the liquid microjet method extensively, and presents the LCP injector as a novel device for serial crystallography, including detailed protocols for the LCP injector and anti-settler operation.

  11. Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

    International Nuclear Information System (INIS)

    Conconi, M.S.; Gauna, M.R.; Serra, M.F.; Suarez, G.; Aglietti, E.F.; Rendtorff, N.M.

    2014-01-01

    The firing transformations of traditional (clay based) ceramics are of technological and archaeological interest, and are usually reported qualitatively or semi quantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite), the low crystalline (metakaolinite and/or spinel type pre-mullite) and glassy phases evolution of a triaxial (clay-quartz-feldspar) ceramic fired in a wide temperature range between 900 and 1300 deg C. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 deg C) spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy) phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and materials

  12. Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

    Energy Technology Data Exchange (ETDEWEB)

    Conconi, M.S.; Gauna, M.R.; Serra, M.F. [Centro de Tecnologia de Recursos Minerales y Ceramica (CETMIC), Buenos Aires (Argentina); Suarez, G.; Aglietti, E.F.; Rendtorff, N.M., E-mail: rendtorff@cetmic.unlp.edu.ar [Universidad Nacional de La Plata (UNLP), Buenos Aires (Argentina). Fac. de Ciencias Exactas. Dept. de Quimica

    2014-10-15

    The firing transformations of traditional (clay based) ceramics are of technological and archaeological interest, and are usually reported qualitatively or semi quantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite), the low crystalline (metakaolinite and/or spinel type pre-mullite) and glassy phases evolution of a triaxial (clay-quartz-feldspar) ceramic fired in a wide temperature range between 900 and 1300 deg C. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 deg C) spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy) phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and materials

  13. Quantitative firing transformations of a triaxial ceramic by X-ray diffraction methods

    Directory of Open Access Journals (Sweden)

    M. S. Conconi

    2014-12-01

    Full Text Available The firing transformations of traditional (clay based ceramics are of technological and archeological interest, and are usually reported qualitatively or semiquantitatively. These kinds of systems present an important complexity, especially for X-ray diffraction techniques, due to the presence of fully crystalline, low crystalline and amorphous phases. In this article we present the results of a qualitative and quantitative X-ray diffraction Rietveld analysis of the fully crystalline (kaolinite, quartz, cristobalite, feldspars and/or mullite, the low crystalline (metakaolinite and/or spinel type pre-mullite and glassy phases evolution of a triaxial (clay-quartz-feldspar ceramic fired in a wide temperature range between 900 and 1300 ºC. The employed methodology to determine low crystalline and glassy phase abundances is based in a combination of the internal standard method and the use of a nanocrystalline model where the long-range order is lost, respectively. A preliminary sintering characterization was carried out by contraction, density and porosity evolution with the firing temperature. Simultaneous thermo-gravimetric and differential thermal analysis was carried out to elucidate the actual temperature at which the chemical changes occur. Finally, the quantitative analysis based on the Rietveld refinement of the X-ray diffraction patterns was performed. The kaolinite decomposition into metakaolinite was determined quantitatively; the intermediate (980 ºC spinel type alumino-silicate formation was also quantified; the incongruent fusion of the potash feldspar was observed and quantified together with the final mullitization and the amorphous (glassy phase formation.The methodology used to analyze the X-ray diffraction patterns proved to be suitable to evaluate quantitatively the thermal transformations that occur in a complex system like the triaxial ceramics. The evaluated phases can be easily correlated with the processing variables and

  14. A simple method for controlling the line width of SASE X-ray FELs

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2010-04-01

    This paper describes a novel single-bunch self-seeding scheme for generating highly monochromatic X-rays from a baseline XFEL undulator. A self-seeded XFEL consists of two undulators with an X-ray monochromator located between them. Previous self-seeding schemes made use of a four-crystal fixed-exit monochromator in Bragg geometry. In such monochromator the X-ray pulse acquires a cm-long path delay, which must be compensated. For a single-bunch self-seeding scheme this requires a long electron beam bypass, implying modifications of the baseline undulator configuration. To avoid this problem, a double bunch self-seeding scheme based on a special photoinjector setup was recently proposed. At variance, here we propose a new time-domain method of monochromatization exploiting a single crystal in the transmission direction, thus avoiding the problem of extra-path delay for the X-ray pulse. The method can be realized using a temporal windowing technique, requiring a magnetic delay for the electron bunch only. When the incident X-ray beam satisfies the Bragg diffraction condition, multiple scattering takes place and the transmittance spectrum in the crystal exhibits an absorption resonance with a narrow linewidth. Then, the temporal waveform of the transmitted radiation pulse is characterized by a long monochromatic wake. The radiation power within this wake is much larger than the shot noise power. At the entrance of the second undulator, the monochromatic wake of the radiation pulse is combined with the delayed electron bunch, and amplified up to saturation level. The proposed setup is extremely simple and composed of as few as two simple elements. These are the crystal and the short magnetic chicane, which accomplishes three tasks by itself. It creates an offset for crystal installation, it removes the electron micro-bunching produced in the first undulator, and it acts as a delay line for temporal windowing. Using a single crystal installed within a short magnetic

  15. Detection of moving capillary front in porous rocks using X-ray and ultrasonic methods

    Directory of Open Access Journals (Sweden)

    Christian eDavid

    2015-07-01

    Full Text Available Several methods are compared for the detection of moving capillary fronts in spontaneous imbibition experiments where water invades dry porous rocks. These methods are: (i the continuous monitoring of the mass increase during imbibition, (ii the imaging of the water front motion using X-ray CT scanning, (iii the use of ultrasonic measurements allowing the detection of velocity, amplitude and spectral content of the propagating elastic waves, and (iv the combined use of X-ray CT scanning and ultrasonic monitoring. It is shown that the properties of capillary fronts depend on the heterogeneity of the rocks, and that the information derived from each method on the dynamics of capillary motion can be significantly different. One important result from the direct comparison of the moving capillary front position and the P wave attributes is that the wave amplitude is strongly impacted before the capillary front reaches the sensors, in contrast with the velocity change which is concomitant with the fluid front arrival in the sensors plane.

  16. A simple method for conversion of airborne gamma-ray spectra to ground level doses

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Bargholz, Kim

    1996-01-01

    A new and simple method for conversion of airborne NaI(Tl) gamma-ray spectra to dose rates at ground level has been developed. By weighting the channel count rates with the channel numbers a spectrum dose index (SDI) is calculated for each spectrum. Ground level dose rates then are determined...... by multiplying the SDI by an altitude dependent conversion factor. The conversion factors are determined from spectra based on Monte Carlo calculations. The results are compared with measurements in a laboratory calibration set-up. IT-NT-27. June 1996. 27 p....

  17. A New Method for Processing Airborne Gamma Ray Spectrometry Data for Mapping Low Level Contaminations

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    1999-01-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia...... where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes Cs-137 at levels often well below 1 kBq/m(2) equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum...

  18. Comparison of various filtering methods for digital X-ray image processing

    International Nuclear Information System (INIS)

    Pfluger, T.; Reinfelder, H.E.; Dorschky, K.; Oppelt, A.; Siemens A.G., Erlangen

    1987-01-01

    Three filtering methods are explained and compared that are used for border edge enhancement of digitally processed X-ray images. The filters are compared by two examples, a radiograph of the chest, and one of the knee joint. The unsharpness mask is found to yield the best compromise between edge enhancement and image noise intensifying effect, whereas the results obtained by the high-pass filter or the Wallis filter are less good for diagnostic evaluation. The filtered images better display narrow lines, structural borders and edges, and finely spotted areas, than the original radiograph, so that diagnostic evaluation is easier after image filtering. (orig.) [de

  19. Preparation of gold nanoparticles by γ-ray irradiation method using polyvinyl pyrrolidone (PVP) as stabilizer

    International Nuclear Information System (INIS)

    Nguyen Tan Man; Le Hai; Le Huu Tu; Tran Thu Hong; Tran Thi Tam; Pham Thi Le Ha; Pham Thi Sam

    2011-01-01

    Gold nanoparticles were prepared from (Au 3+ ) aqueous solution by the method of γ-ray irradiation using polyvinylpyrrolidone (PVP) as stabilizer. The saturated conversion dose (Au 3+ --> Au o ) determined by UV-Vis spectroscopy was found to be about 5 kGy. The UV-Vis spectrum showed that an absorption peak at λ max =524 nm due to surface plasmon resonance. The image of transmission electron microscopy (TEM) showed that the gold nanoparticles are mostly spherical in shape and have an average diameter of ≅20 nm. The prepared colloidal gold nanoparticles solution is good stability for 6 months of storage. (author)

  20. New analytical method for asbestos determination in Syrian soils using X-ray diffraction

    International Nuclear Information System (INIS)

    Kassem, M.

    2009-07-01

    In this work, a standard samples have been prepared by mixing a definite quantity of soil with calculated concentration of asbestos; 1, 2, 4, 8, 10, 20, 40, 60, 80, 100% wt . The samples have been analyzed by x-ray powder diffraction using the same parameters ; 2θ between 5-90, detector step= 0.5 /30 sec. The diffraction peaks intensities have been chosen such a manner than no superposition with those of the soil. confidence levels has been used as accuracy method for error calculation of the peaks positions. (author)

  1. A method for assessing the structural shielding in diagnostic x-ray facilities

    International Nuclear Information System (INIS)

    Almeida, F.; Martinez de la Fuente, O.; Perez, C.

    1992-01-01

    The design of each X-Ray medical facility involves, in order to guarantee the optimun levels of Radiologic safety for everybody who could be exposed during the performance of the examinations the need of assessing the required shieldings for the room which contains the emiter tubes. In such sense, this paper gives a number of criteria to calculate the structural requirements for the diverse configurations which exist in Health Centres using the method proposed by NCRP in its Report 49 as a reference. (author)

  2. A novel process control method for a TT-300 E-Beam/X-Ray system

    Science.gov (United States)

    Mittendorfer, Josef; Gallnböck-Wagner, Bernhard

    2018-02-01

    This paper presents some aspects of the process control method for a TT-300 E-Beam/X-Ray system at Mediscan, Austria. The novelty of the approach is the seamless integration of routine monitoring dosimetry with process data. This allows to calculate a parametric dose for each production unit and consequently a fine grain and holistic process performance monitoring. Process performance is documented in process control charts for the analysis of individual runs as well as historic trending of runs of specific process categories over a specified time range.

  3. Direct method of deconvolution. Application to the interpretation of X ray diffraction line profiles

    International Nuclear Information System (INIS)

    Louer, Daniel

    1969-01-01

    In the first parts of this research thesis, the author reports the development of an original method of correction of X ray profiles, and the comparison of the different correction schemes within the frame of the analysis of a specific aberration of the diffractometer: the receiver slot. Based on corrected profiles, the author applied the different methods leading to the calculation of the dimensions and shape of particles which form a hydroxide nickel powder. He reports the physical-chemical analysis of nickel and zinc basic nitrates. Although some basic salts lead to widened X diffraction profiles the interpretation of which remains to be made, this work remained limited to the application of the described methods to the nickel hydroxide sample resulting from an extended hydrolysis of nickel basic nitrates

  4. Comparison of alternative methods for multiplet deconvolution in the analysis of gamma-ray spectra

    International Nuclear Information System (INIS)

    Blaauw, Menno; Keyser, Ronald M.; Fazekas, Bela

    1999-01-01

    Three methods for multiplet deconvolution were tested using the 1995 IAEA reference spectra: Total area determination, iterative fitting and the library-oriented approach. It is concluded that, if statistical control (i.e. the ability to report results that agree with the known, true values to within the reported uncertainties) is required, the total area determination method performs the best. If high deconvolution power is required and a good, internally consistent library is available, the library oriented method yields the best results. Neither Erdtmann and Soyka's gamma-ray catalogue nor Browne and Firestone's Table of Radioactive Isotopes were found to be internally consistent enough in this respect. In the absence of a good library, iterative fitting with restricted peak width variation performs the best. The ultimate approach as yet to be implemented might be library-oriented fitting with allowed peak position variation according to the peak energy uncertainty specified in the library. (author)

  5. Preliminary report on an intercomparison of methods for processing Ge(Li) gamma-ray spectra

    International Nuclear Information System (INIS)

    Parr, R.M.; Houtermans, H.; Schaerf, K.

    1978-01-01

    An intercomparison has been organized by the IAEA for the purpose of evaluating methods for processing Ge(Li) gamma-ray spectra. These spectra cover an energy range of about 1MeV and, with one exception, contain only well separated single peaks; another spectrum contains double peaks with various relative intensities and degrees of overlap. The spectra were prepared in such a way that the areas and positions of all peaks, relative to a standard spectrum which is also provided, are known exactly. The intercomparison enables the user to test the ability of his methods (1) to detect small peaks near the limit of detectability; (2) to determine the position and area of more easily detectable peaks, and (3) to determine the position and area of overlapping double peaks. The method of preparation of the spectra and the organization of the intercomparison are described in this report. (author)

  6. Cluster cosmological analysis with X ray instrumental observables: introduction and testing of AsPIX method

    International Nuclear Information System (INIS)

    Valotti, Andrea

    2016-01-01

    Cosmology is one of the fundamental pillars of astrophysics, as such it contains many unsolved puzzles. To investigate some of those puzzles, we analyze X-ray surveys of galaxy clusters. These surveys are possible thanks to the bremsstrahlung emission of the intra-cluster medium. The simultaneous fit of cluster counts as a function of mass and distance provides an independent measure of cosmological parameters such as Ω m , σ s , and the dark energy equation of state w0. A novel approach to cosmological analysis using galaxy cluster data, called top-down, was developed in N. Clerc et al. (2012). This top-down approach is based purely on instrumental observables that are considered in a two-dimensional X-ray color-magnitude diagram. The method self-consistently includes selection effects and scaling relationships. It also provides a means of bypassing the computation of individual cluster masses. My work presents an extension of the top-down method by introducing the apparent size of the cluster, creating a three-dimensional X-ray cluster diagram. The size of a cluster is sensitive to both the cluster mass and its angular diameter, so it must also be included in the assessment of selection effects. The performance of this new method is investigated using a Fisher analysis. In parallel, I have studied the effects of the intrinsic scatter in the cluster size scaling relation on the sample selection as well as on the obtained cosmological parameters. To validate the method, I estimate uncertainties of cosmological parameters with MCMC method Amoeba minimization routine and using two simulated XMM surveys that have an increasing level of complexity. The first simulated survey is a set of toy catalogues of 100 and 10000 deg 2 , whereas the second is a 1000 deg 2 catalogue that was generated using an Aardvark semi-analytical N-body simulation. This comparison corroborates the conclusions of the Fisher analysis. In conclusion, I find that a cluster diagram that accounts

  7. Reconstruction of computed tomographic image from a few x-ray projections by means of accelerative gradient method

    International Nuclear Information System (INIS)

    Kobayashi, Fujio; Yamaguchi, Shoichiro

    1982-01-01

    A method of the reconstruction of computed tomographic images was proposed to reduce the exposure dose to X-ray. The method is the small number of X-ray projection method by accelerative gradient method. The procedures of computation are described. The algorithm of these procedures is simple, the convergence of the computation is fast, and the required memory capacity is small. Numerical simulation was carried out to conform the validity of this method. A sample of simple shape was considered, projection data were given, and the images were reconstructed from 6 views. Good results were obtained, and the method is considered to be useful. (Kato, T.)

  8. Study of properties of chemically modified samples of halloysite mineral with X-ray fluorescence and X-ray powder diffraction methods

    International Nuclear Information System (INIS)

    Banaś, D.; Kubala-Kukuś, A.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Moćko, J.; Czech, K.; Garnuszek, M.; Słomkiewicz, P.; Szczepanik, B.

    2013-01-01

    Elemental and chemical composition of raw and activated samples of halloysite mineral using wavelength dispersive X-ray fluorescence (WDXRF), total reflection X-ray fluorescence (TXRF) and X-ray powder diffraction (XRPD) methods were determined. As the result, it has been shown that application of the complementary X-ray spectrometry techniques allows very precise observation of changes in composition of halloysite mineral samples caused by its chemical modifications. Sample preparation procedure and usability of the research methods applied are described in details. Procedure of activation of raw halloysite mineral samples by etching them in sulfuric acid of various concentrations has been described and discussed. The ability of the samples to adsorb lead from intentionally contaminated water was tested and confirmed. - Author-Highlights: • We measured elemental and chemical composition of raw and activated halloysite mineral samples. • We showed that X-ray techniques allow precise study of changes in the sample composition. • We describe procedure of activation of the samples by etching them in sulfuric acid. • We tested ability of halloysite mineral to absorb lead from contaminated water

  9. GRASP. Development of an event reconstruction method using a gamma ray air shower parameterisation and applications to γ-ray sources with H.E.S.S

    Energy Technology Data Exchange (ETDEWEB)

    Hillert, Andreas

    2014-07-24

    The H.E.S.S. experiment, with its high sensitivity and large field-of-view, is an ideal instrument to survey the Milky Way in VHE γ-rays. An accurate reconstruction of the γ-ray direction as well as a strong reduction of the hadronic background is essential for the analysis of the data. In this work a reconstruction algorithm is developed that applies a fit of pixel amplitudes to an expected image obtained from a Gamma Ray Air Shower Parameterisation (GRASP). This parameterisation was obtained using Monte Carlo air shower simulations by parameterising the angular Cherenkov photon distribution with suitable analytical functions. Furthermore, it provides new classifying variables to differentiate γ-ray induced air showers from hadronic ones. The reconstruction of air shower parameters is achieved by a maximum likelihood fit and improves the angular resolution by 20-30% with respect to traditional image moment analysis methods. In combination with a MVA-based background rejection method using these new classifying variables the sensitivity can be improved by about 70%. An analysis of the Pulsar Wind Nebula MSH 15-5-2 and investigation of its morphology and spectral properties show an indication of energy dependent morphology in VHE γ-rays.

  10. Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals.

    Science.gov (United States)

    Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun; Xu, Cao

    2016-01-01

    Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.

  11. Study Of Soot Growth And Nucleation By A Time-Resolved Synchrotron Radiation Based X-Ray Absorption Method

    National Research Council Canada - National Science Library

    Mitchell, Judith I

    2001-01-01

    This report results from a contract tasking University of Rennes I as follows: The contractor will perform a study of soot growth and nucleation by a time-resolved synchrotron radiation based x-ray absorption method...

  12. Non-invasive analysis of industrial products using the simultaneous transmission of neutrons and gamma rays (Neugat) method

    International Nuclear Information System (INIS)

    Bartle, C.M.

    1998-01-01

    This research programme is designed to develop industrial measurement systems utilising simultaneous transmission of neutrons and gamma rays (Neugat method). Descriptions of these systems have been given in reports and magazine articles, and industrial site trials have been undertaken. (author)

  13. Application of proton-induced X-ray emission method to determination of lead content in blood

    International Nuclear Information System (INIS)

    Slominska, D.; Jarczyk, L.; Rokita, E.; Strzalkowski, A.; Losiowski, A.; Macheta, A.; Sych, M.; Moszkowicz, S.

    1979-01-01

    The proton induced X-ray emission method is applied for determination of lead content in the blood of the people exposed to contact with ethyline vapours and people working in lead-zinc works. (author)

  14. Comparison of a semi-empirical method with some model codes for gamma-ray spectrum calculation

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Fan; Zhixiang, Zhao [Chinese Nuclear Data Center, Beijing, BJ (China)

    1996-06-01

    Gamma-ray spectra calculated by a semi-empirical method are compared with those calculated by the model codes such as GNASH, TNG, UNF and NDCP-1. The results of the calculations are discussed. (2 tabs., 3 figs.).

  15. Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison

    International Nuclear Information System (INIS)

    Yan, Aimin; Wu, Xizeng; Liu, Hong

    2011-01-01

    Purpose: The robustness of the phase retrieval methods is of critical importance for limiting and reducing radiation doses involved in x-ray phase contrast imaging. This work is to compare the robustness of two phase retrieval methods by analyzing the phase maps retrieved from the experimental images of a phantom. Methods: Two phase retrieval methods were compared. One method is based on the transport of intensity equation (TIE) for phase contrast projections, and the TIE-based method is the most commonly used method for phase retrieval in the literature. The other is the recently developed attenuation-partition based (AP-based) phase retrieval method. The authors applied these two methods to experimental projection images of an air-bubble wrap phantom for retrieving the phase map of the bubble wrap. The retrieved phase maps obtained by using the two methods are compared. Results: In the wrap's phase map retrieved by using the TIE-based method, no bubble is recognizable, hence, this method failed completely for phase retrieval from these bubble wrap images. Even with the help of the Tikhonov regularization, the bubbles are still hardly visible and buried in the cluttered background in the retrieved phase map. The retrieved phase values with this method are grossly erroneous. In contrast, in the wrap's phase map retrieved by using the AP-based method, the bubbles are clearly recovered. The retrieved phase values with the AP-based method are reasonably close to the estimate based on the thickness-based measurement. The authors traced these stark performance differences of the two methods to their different techniques employed to deal with the singularity problem involved in the phase retrievals. Conclusions: This comparison shows that the conventional TIE-based phase retrieval method, regardless if Tikhonov regularization is used or not, is unstable against the noise in the wrap's projection images, while the AP-based phase retrieval method is shown in these

  16. X-ray scatter correction method for dedicated breast computed tomography: improvements and initial patient testing

    International Nuclear Information System (INIS)

    Ramamurthy, Senthil; D’Orsi, Carl J; Sechopoulos, Ioannis

    2016-01-01

    A previously proposed x-ray scatter correction method for dedicated breast computed tomography was further developed and implemented so as to allow for initial patient testing. The method involves the acquisition of a complete second set of breast CT projections covering 360° with a perforated tungsten plate in the path of the x-ray beam. To make patient testing feasible, a wirelessly controlled electronic positioner for the tungsten plate was designed and added to a breast CT system. Other improvements to the algorithm were implemented, including automated exclusion of non-valid primary estimate points and the use of a different approximation method to estimate the full scatter signal. To evaluate the effectiveness of the algorithm, evaluation of the resulting image quality was performed with a breast phantom and with nine patient images. The improvements in the algorithm resulted in the avoidance of introduction of artifacts, especially at the object borders, which was an issue in the previous implementation in some cases. Both contrast, in terms of signal difference and signal difference-to-noise ratio were improved with the proposed method, as opposed to with the correction algorithm incorporated in the system, which does not recover contrast. Patient image evaluation also showed enhanced contrast, better cupping correction, and more consistent voxel values for the different tissues. The algorithm also reduces artifacts present in reconstructions of non-regularly shaped breasts. With the implemented hardware and software improvements, the proposed method can be reliably used during patient breast CT imaging, resulting in improvement of image quality, no introduction of artifacts, and in some cases reduction of artifacts already present. The impact of the algorithm on actual clinical performance for detection, diagnosis and other clinical tasks in breast imaging remains to be evaluated. (paper)

  17. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    International Nuclear Information System (INIS)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S

    2006-01-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process

  18. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-dong, Daejeon (Korea, Republic of)

    2006-04-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process.

  19. Reconstruction of X-rays spectra of clinical linear accelerators using the generalized simulated annealing method

    International Nuclear Information System (INIS)

    Manrique, John Peter O.; Costa, Alessandro M.

    2016-01-01

    The spectral distribution of megavoltage X-rays used in radiotherapy departments is a fundamental quantity from which, in principle, all relevant information required for radiotherapy treatments can be determined. To calculate the dose delivered to the patient who make radiation therapy, are used treatment planning systems (TPS), which make use of convolution and superposition algorithms and which requires prior knowledge of the photon fluence spectrum to perform the calculation of three-dimensional doses and thus ensure better accuracy in the tumor control probabilities preserving the normal tissue complication probabilities low. In this work we have obtained the photon fluence spectrum of X-ray of the SIEMENS ONCOR linear accelerator of 6 MV, using an character-inverse method to the reconstruction of the spectra of photons from transmission curves measured for different thicknesses of aluminum; the method used for reconstruction of the spectra is a stochastic technique known as generalized simulated annealing (GSA), based on the work of quasi-equilibrium statistic of Tsallis. For the validation of the reconstructed spectra we calculated the curve of percentage depth dose (PDD) for energy of 6 MV, using Monte Carlo simulation with Penelope code, and from the PDD then calculate the beam quality index TPR_2_0_/_1_0. (author)

  20. Basis material decomposition method for material discrimination with a new spectrometric X-ray imaging detector

    Science.gov (United States)

    Brambilla, A.; Gorecki, A.; Potop, A.; Paulus, C.; Verger, L.

    2017-08-01

    Energy sensitive photon counting X-ray detectors provide energy dependent information which can be exploited for material identification. The attenuation of an X-ray beam as a function of energy depends on the effective atomic number Zeff and the density. However, the measured attenuation is degraded by the imperfections of the detector response such as charge sharing or pile-up. These imperfections lead to non-linearities that limit the benefits of energy resolved imaging. This work aims to implement a basis material decomposition method which overcomes these problems. Basis material decomposition is based on the fact that the attenuation of any material or complex object can be accurately reproduced by a combination of equivalent thicknesses of basis materials. Our method is based on a calibration phase to learn the response of the detector for different combinations of thicknesses of the basis materials. The decomposition algorithm finds the thicknesses of basis material whose spectrum is closest to the measurement, using a maximum likelihood criterion assuming a Poisson law distribution of photon counts for each energy bin. The method was used with a ME100 linear array spectrometric X-ray imager to decompose different plastic materials on a Polyethylene and Polyvinyl Chloride base. The resulting equivalent thicknesses were used to estimate the effective atomic number Zeff. The results are in good agreement with the theoretical Zeff, regardless of the plastic sample thickness. The linear behaviour of the equivalent lengths makes it possible to process overlapped materials. Moreover, the method was tested with a 3 materials base by adding gadolinium, whose K-edge is not taken into account by the other two materials. The proposed method has the advantage that it can be used with any number of energy channels, taking full advantage of the high energy resolution of the ME100 detector. Although in principle two channels are sufficient, experimental measurements show

  1. Simulation of x-rays in refractive structure by the Monte Carlo method using the supercomputer SKIF

    International Nuclear Information System (INIS)

    Yaskevich, Yu.R.; Kravchenko, O.I.; Soroka, I.I.; Chembrovskij, A.G.; Kolesnik, A.S.; Serikova, N.V.; Petrov, P.V.; Kol'chevskij, N.N.

    2013-01-01

    Software 'Xray-SKIF' for the simulation of the X-rays in refractive structures by the Monte-Carlo method using the supercomputer SKIF BSU are developed. The program generates a large number of rays propagated from a source to the refractive structure. The ray trajectory under assumption of geometrical optics is calculated. Absorption is calculated for each ray inside of refractive structure. Dynamic arrays are used for results of calculation rays parameters, its restore the X-ray field distributions very fast at different position of detector. It was found that increasing the number of processors leads to proportional decreasing of calculation time: simulation of 10 8 X-rays using supercomputer with the number of processors from 1 to 30 run-times equal 3 hours and 6 minutes, respectively. 10 9 X-rays are calculated by software 'Xray-SKIF' which allows to reconstruct the X-ray field after refractive structure with a special resolution of 1 micron. (authors)

  2. A simple method for generation of back-ground-free gamma-ray spectra

    International Nuclear Information System (INIS)

    Kawarasaki, Y.

    1976-01-01

    A simple and versatile method of generating background-free γ-ray spectra is presented. This method is equivalent to the generation of a continuous background baseline over the entire energy range of spectra corresponding to the original ones obtained with a Ge(Li) detector. These background curves can not be generally expressed in a single and simple analytic form nor in the form of a power series. These background-free spectra thus obtained make it feasible to assign many tiny peaks at the stage of visual inspection of the spectra, which is difficult to do with the original ones. The automatic peak-finding and peak area calculation procedures are both applicable to these background-free spectra. Examples of the application are illustrated. The effect of the peak-shape distortion is also discussed. (Auth.)

  3. Validation of the X-ray fluorescence analysis method for coffee grain testing

    International Nuclear Information System (INIS)

    Samaniego, Carlos

    1992-01-01

    Trace elements were qualitatively and quantitatively searched for in coffee samples for analysis were prepared in tablet from before irradiation, this latter having been performed with a Cd 109 radioactive source and with an X-ray tube; with ZnO as the secondary target. Several spectra were obtained. The areas of the spectral peaks were adjusted with the aid of AXIL computer program wich is based on the least squares method. Further on, elemental concentrations were determined by means of sensitivity and regression curves (intensity vs. concentration), methods that demanded the use of pertinent standards, concentration in organic standard certified samples furthermore, atomic absorption was also used to perform comparative checks on results

  4. A General Method for Motion Compensation in X-ray Computed Tomography

    CERN Document Server

    AUTHOR|(CDS)2067162; Dosanjh, Manjit; Soleimani, Manuchehr

    2017-01-01

    Motion during data acquisition is a known source of error in medical tomography, resulting in blur artefacts in the regions that move. It is critical to reduce these artefacts in applications such as image-guided radiation therapy as a clearer image translates into a more accurate treatment and the sparing of healthy tissue close to a tumour site. Most research in 4D X-ray tomography involving the thorax relies on respiratory phase binning of the acquired data and reconstructing each of a set of images using the limited subset of data per phase. In this work, we demonstrate a motion-compensation method to reconstruct images from the complete dataset taken during breathing without recourse to phase-binning or breath-hold techniques. As long as the motion is sufficiently well known, the new method can accurately reconstruct an image at any time during the acquisition time span. It can be applied to any iterative reconstruction algorithm.

  5. Development of direct observation aparatus of coal carbonization process by x-ray computerized tomography method

    International Nuclear Information System (INIS)

    Sakawa, Mitsuhiro; Shiraishi, Katsuhiko; Sakurai, Yoshihisa; Shimomura, Yasuto

    1987-01-01

    Coke production by chamber ovens has a long history and efforts are being continued to make the manufacturing process efficient and to preserve the environment. In this production by this method, however, it is hardly possible to obtain direct information during coal carbonization. Since the elements that compose coal and coke are carbon, hydrogen, oxygen, etc. and are similar to those of the human body, authors has developed a coke oven that permits the direct observation of the coal carbonization process using a soft X-ray computerized tomography (CT) apparatus used in medical treatment. The following phenomena can be observed as images by the coke oven for the CT method : 1) Changes in the bulk density of charge coal (including the difference in the water content), 2) Width of the plastic layer and movement of the plastic layer in the coke oven chamber, 3) Expansion and shrinkage of the charge in the coke oven chamber, 4) Initiation and growth of cracks. (author)

  6. A general method for motion compensation in x-ray computed tomography.

    Science.gov (United States)

    Biguri, Ander; Dosanjh, Manjit; Hancock, Steven; Soleimani, Manuchehr

    2017-07-24

    Motion during data acquisition is a known source of error in medical tomography, resulting in blur artefacts in the regions that move. It is critical to reduce these artefacts in applications such as image-guided radiation therapy as a clearer image translates into a more accurate treatment and the sparing of healthy tissue close to a tumour site. Most research in 4D x-ray tomography involving the thorax relies on respiratory phase binning of the acquired data and reconstructing each of a set of images using the limited subset of data per phase. In this work, we demonstrate a motion-compensation method to reconstruct images from the complete dataset taken during breathing without recourse to phase-binning or breath-hold techniques. As long as the motion is sufficiently well known, the new method can accurately reconstruct an image at any time during the acquisition time span. It can be applied to any iterative reconstruction algorithm.

  7. A general method for motion compensation in x-ray computed tomography

    Science.gov (United States)

    Biguri, Ander; Dosanjh, Manjit; Hancock, Steven; Soleimani, Manuchehr

    2017-08-01

    Motion during data acquisition is a known source of error in medical tomography, resulting in blur artefacts in the regions that move. It is critical to reduce these artefacts in applications such as image-guided radiation therapy as a clearer image translates into a more accurate treatment and the sparing of healthy tissue close to a tumour site. Most research in 4D x-ray tomography involving the thorax relies on respiratory phase binning of the acquired data and reconstructing each of a set of images using the limited subset of data per phase. In this work, we demonstrate a motion-compensation method to reconstruct images from the complete dataset taken during breathing without recourse to phase-binning or breath-hold techniques. As long as the motion is sufficiently well known, the new method can accurately reconstruct an image at any time during the acquisition time span. It can be applied to any iterative reconstruction algorithm.

  8. The fundamental parameter method applied to X-ray fluorescence analysis with synchrotron radiation

    Science.gov (United States)

    Pantenburg, F. J.; Beier, T.; Hennrich, F.; Mommsen, H.

    1992-05-01

    Quantitative X-ray fluorescence analysis applying the fundamental parameter method is usually restricted to monochromatic excitation sources. It is shown here, that such analyses can be performed as well with a white synchrotron radiation spectrum. To determine absolute elemental concentration values it is necessary to know the spectral distribution of this spectrum. A newly designed and tested experimental setup, which uses the synchrotron radiation emitted from electrons in a bending magnet of ELSA (electron stretcher accelerator of the university of Bonn) is presented. The determination of the exciting spectrum, described by the given electron beam parameters, is limited due to uncertainties in the vertical electron beam size and divergence. We describe a method which allows us to determine the relative and absolute spectral distributions needed for accurate analysis. First test measurements of different alloys and standards of known composition demonstrate that it is possible to determine exact concentration values in bulk and trace element analysis.

  9. Introducing GAMER: A Fast and Accurate Method for Ray-tracing Galaxies Using Procedural Noise

    Science.gov (United States)

    Groeneboom, N. E.; Dahle, H.

    2014-03-01

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  10. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    International Nuclear Information System (INIS)

    Groeneboom, N. E.; Dahle, H.

    2014-01-01

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  11. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    Energy Technology Data Exchange (ETDEWEB)

    Groeneboom, N. E.; Dahle, H., E-mail: nicolaag@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

    2014-03-10

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  12. Ray tracing method for simulation of laser beam interaction with random packings of powders

    Science.gov (United States)

    Kovalev, O. B.; Kovaleva, I. O.; Belyaev, V. V.

    2018-03-01

    Selective laser sintering is a technology of rapid manufacturing of a free form that is created as a solid object by selectively fusing successive layers of powder using a laser. The motivation of this study is due to the currently insufficient understanding of the processes and phenomena of selective laser melting of powders whose time scales differ by orders of magnitude. To construct random packings from mono- and polydispersed solid spheres, the algorithm of their generation based on the discrete element method is used. A numerical method of ray tracing is proposed that is used to simulate the interaction of laser radiation with a random bulk packing of spherical particles and to predict the optical properties of the granular layer, the extinction and absorption coefficients, depending on the optical properties of a powder material.

  13. System Characterizations and Optimized Reconstruction Methods for Novel X-ray Imaging Modalities

    Science.gov (United States)

    Guan, Huifeng

    In the past decade there have been many new emerging X-ray based imaging technologies developed for different diagnostic purposes or imaging tasks. However, there exist one or more specific problems that prevent them from being effectively or efficiently employed. In this dissertation, four different novel X-ray based imaging technologies are discussed, including propagation-based phase-contrast (PB-XPC) tomosynthesis, differential X-ray phase-contrast tomography (D-XPCT), projection-based dual-energy computed radiography (DECR), and tetrahedron beam computed tomography (TBCT). System characteristics are analyzed or optimized reconstruction methods are proposed for these imaging modalities. In the first part, we investigated the unique properties of propagation-based phase-contrast imaging technique when combined with the X-ray tomosynthesis. Fourier slice theorem implies that the high frequency components collected in the tomosynthesis data can be more reliably reconstructed. It is observed that the fringes or boundary enhancement introduced by the phase-contrast effects can serve as an accurate indicator of the true depth position in the tomosynthesis in-plane image. In the second part, we derived a sub-space framework to reconstruct images from few-view D-XPCT data set. By introducing a proper mask, the high frequency contents of the image can be theoretically preserved in a certain region of interest. A two-step reconstruction strategy is developed to mitigate the risk of subtle structures being oversmoothed when the commonly used total-variation regularization is employed in the conventional iterative framework. In the thirt part, we proposed a practical method to improve the quantitative accuracy of the projection-based dual-energy material decomposition. It is demonstrated that applying a total-projection-length constraint along with the dual-energy measurements can achieve a stabilized numerical solution of the decomposition problem, thus overcoming the

  14. Scatter correction method for x-ray CT using primary modulation: Phantom studies

    International Nuclear Information System (INIS)

    Gao Hewei; Fahrig, Rebecca; Bennett, N. Robert; Sun Mingshan; Star-Lack, Josh; Zhu Lei

    2010-01-01

    Purpose: Scatter correction is a major challenge in x-ray imaging using large area detectors. Recently, the authors proposed a promising scatter correction method for x-ray computed tomography (CT) using primary modulation. Proof of concept was previously illustrated by Monte Carlo simulations and physical experiments on a small phantom with a simple geometry. In this work, the authors provide a quantitative evaluation of the primary modulation technique and demonstrate its performance in applications where scatter correction is more challenging. Methods: The authors first analyze the potential errors of the estimated scatter in the primary modulation method. On two tabletop CT systems, the method is investigated using three phantoms: A Catphan(c)600 phantom, an anthropomorphic chest phantom, and the Catphan(c)600 phantom with two annuli. Two different primary modulators are also designed to show the impact of the modulator parameters on the scatter correction efficiency. The first is an aluminum modulator with a weak modulation and a low modulation frequency, and the second is a copper modulator with a strong modulation and a high modulation frequency. Results: On the Catphan(c)600 phantom in the first study, the method reduces the error of the CT number in the selected regions of interest (ROIs) from 371.4 to 21.9 Hounsfield units (HU); the contrast to noise ratio also increases from 10.9 to 19.2. On the anthropomorphic chest phantom in the second study, which represents a more difficult case due to the high scatter signals and object heterogeneity, the method reduces the error of the CT number from 327 to 19 HU in the selected ROIs and from 31.4% to 5.7% on the overall average. The third study is to investigate the impact of object size on the efficiency of our method. The scatter-to-primary ratio estimation error on the Catphan(c)600 phantom without any annulus (20 cm in diameter) is at the level of 0.04, it rises to 0.07 and 0.1 on the phantom with an

  15. X-ray fluorescence analysis of strontium in environmental water by using barium carbonate coprecipitation method

    International Nuclear Information System (INIS)

    Nishioka, Hiroshi; Yoneda, Akio; Maeda, Yoshimichi; Azumi, Takatugu

    1986-01-01

    Determination of strontium in environmental water was studied by a coprecipitation method with barium carbonate and the subsequent X-ray fluorescence analysis. Fifty mg of barium ion and 1 g of sodium carbonate were added to sample water, which was then mixed for one hour by a magnetic stirrer. Precipitate was gathered onto a membrane filter paper to measure its XF intensity. The amount of strontium from 2 to 150 μg could be repeatedly determined by means of the calibration curve method, and the limit of detection was found to be 0.6 μg of strontium. A large amount of calcium and magnesium ions was found to interfere with the coprecipitation of strontium ion. However, this interference could be eliminated by using a small amount of sample water. Strontium in several environmental waters was determined by the above method. The results obtained from the calibration curve method and the standard addition method agreed with each other, and also agreed with those from the atomic absorption spectrometry. (author)

  16. Soft X-ray-assisted detection method for airborne molecular contaminations (AMCs)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Changhyuk; Zuo, Zhili [University of Minnesota, Department of Mechanical Engineering (United States); Finger, Hartmut; Haep, Stefan; Asbach, Christof; Fissan, Heinz [Institute of Energy and Environmental Technology (IUTA e. V.) (Germany); Pui, David Y. H., E-mail: dyhpui@umn.edu [University of Minnesota, Department of Mechanical Engineering (United States)

    2015-03-15

    Airborne molecular contaminations (AMCs) represent a wide range of gaseous contaminants in cleanrooms. Due to the unintentional nanoparticle or haze formation as well as doping caused by AMCs, improved monitoring and controlling methods for AMCs are urgent in the semiconductor industry. However, measuring ultra-low concentrations of AMCs in cleanrooms is difficult, especially, behind a gas filter. In this study, a novel detection method for AMCs, which is on-line, economical, and applicable for diverse AMCs, was developed by employing gas-to-particle conversion with soft X-ray, and then measuring the generated nanoparticles. Feasibility study of this method was conducted through the evaluations of granular-activated carbons (GACs), which are widely used AMC filter media. Sulfur dioxide (SO{sub 2}) was used as an AMC for the feasibility study. Using this method, the ultra-low concentrations of SO{sub 2} behind GACs were determined in terms of concentrations of generated sulfuric acid (H{sub 2}SO{sub 4}) nanoparticles. By calculating SO{sub 2} concentrations from the nanoparticle concentrations using empirical correlation equations between them, remarkable sensitivity of this method to SO{sub 2} was shown, down to parts-per-trillions, which are too low to detect using commercial gas sensors. Also, the calculated SO{sub 2} concentrations showed good agreement with those measured simultaneously by a commercial SO{sub 2} monitor at parts-per-billions.

  17. A new 3-D ray tracing method based on LTI using successive partitioning of cell interfaces and traveltime gradients

    Science.gov (United States)

    Zhang, Dong; Zhang, Ting-Ting; Zhang, Xiao-Lei; Yang, Yan; Hu, Ying; Qin, Qian-Qing

    2013-05-01

    We present a new method of three-dimensional (3-D) seismic ray tracing, based on an improvement to the linear traveltime interpolation (LTI) ray tracing algorithm. This new technique involves two separate steps. The first involves a forward calculation based on the LTI method and the dynamic successive partitioning scheme, which is applied to calculate traveltimes on cell boundaries and assumes a wavefront that expands from the source to all grid nodes in the computational domain. We locate several dynamic successive partition points on a cell's surface, the traveltimes of which can be calculated by linear interpolation between the vertices of the cell's boundary. The second is a backward step that uses Fermat's principle and the fact that the ray path is always perpendicular to the wavefront and follows the negative traveltime gradient. In this process, the first-arriving ray path can be traced from the receiver to the source along the negative traveltime gradient, which can be calculated by reconstructing the continuous traveltime field with cubic B-spline interpolation. This new 3-D ray tracing method is compared with the LTI method and the shortest path method (SPM) through a number of numerical experiments. These comparisons show obvious improvements to computed traveltimes and ray paths, both in precision and computational efficiency.

  18. A method for volumetric imaging in radiotherapy using single x-ray projection

    International Nuclear Information System (INIS)

    Xu, Yuan; Yan, Hao; Ouyang, Luo; Wang, Jing; Jiang, Steve B.; Jia, Xun; Zhou, Linghong; Cervino, Laura

    2015-01-01

    Purpose: It is an intriguing problem to generate an instantaneous volumetric image based on the corresponding x-ray projection. The purpose of this study is to develop a new method to achieve this goal via a sparse learning approach. Methods: To extract motion information hidden in projection images, the authors partitioned a projection image into small rectangular patches. The authors utilized a sparse learning method to automatically select patches that have a high correlation with principal component analysis (PCA) coefficients of a lung motion model. A model that maps the patch intensity to the PCA coefficients was built along with the patch selection process. Based on this model, a measured projection can be used to predict the PCA coefficients, which are then further used to generate a motion vector field and hence a volumetric image. The authors have also proposed an intensity baseline correction method based on the partitioned projection, in which the first and the second moments of pixel intensities at a patch in a simulated projection image are matched with those in a measured one via a linear transformation. The proposed method has been validated in both simulated data and real phantom data. Results: The algorithm is able to identify patches that contain relevant motion information such as the diaphragm region. It is found that an intensity baseline correction step is important to remove the systematic error in the motion prediction. For the simulation case, the sparse learning model reduced the prediction error for the first PCA coefficient to 5%, compared to the 10% error when sparse learning was not used, and the 95th percentile error for the predicted motion vector was reduced from 2.40 to 0.92 mm. In the phantom case with a regular tumor motion, the predicted tumor trajectory was successfully reconstructed with a 0.82 mm error for tumor center localization compared to a 1.66 mm error without using the sparse learning method. When the tumor motion

  19. A fit method for the determination of inherent filtration with diagnostic x-ray units

    International Nuclear Information System (INIS)

    Meghzifene, K; Nowotny, R; Aiginger, H

    2006-01-01

    A method for the determination of total inherent filtration for clinical x-ray units using attenuation curves was devised. A model for the calculation of x-ray spectra is used to calculate kerma values which are then adjusted to the experimental data in minimizing the sum of the squared relative differences in kerma using a modified simplex fit process. The model considers tube voltage, voltage ripple, anode angle and additional filters. Fit parameters are the thickness of an additional inherent Al filter and a general normalization factor. Nineteen sets of measurements including attenuation data for three tube voltages and five Al-filter settings each were obtained. Relative differences of experimental and calculated kerma using the data for the additional filter thickness are within a range of -7.6% to 6.4%. Quality curves, i.e. the relationship of additional filtration to HVL, are often used to determine filtration but the results show that standard quality curves do not reflect the variety of conditions encountered in practice. To relate the thickness of the additional filter to the condition of the anode surface, the data fits were also made using tungsten as the filter material. These fits gave an identical fit quality compared to aluminium with a tungsten filter thickness of 2.12-8.21 μm which is within the range of the additional absorbing layers determined for rough anodes

  20. Methods for fitting of efficiency curves obtained by means of HPGe gamma rays spectrometers

    International Nuclear Information System (INIS)

    Cardoso, Vanderlei

    2002-01-01

    The present work describes a few methodologies developed for fitting efficiency curves obtained by means of a HPGe gamma-ray spectrometer. The interpolated values were determined by simple polynomial fitting and polynomial fitting between the ratio of experimental peak efficiency and total efficiency, calculated by Monte Carlo technique, as a function of gamma-ray energy. Moreover, non-linear fitting has been performed using a segmented polynomial function and applying the Gauss-Marquardt method. For the peak area obtainment different methodologies were developed in order to estimate the background area under the peak. This information was obtained by numerical integration or by using analytical functions associated to the background. One non-calibrated radioactive source has been included in the curve efficiency in order to provide additional calibration points. As a by-product, it was possible to determine the activity of this non-calibrated source. For all fittings developed in the present work the covariance matrix methodology was used, which is an essential procedure in order to give a complete description of the partial uncertainties involved. (author)

  1. EMA beamline at SIRIUS: extreme condition X-ray methods of analysis

    International Nuclear Information System (INIS)

    Souza Neto, Narcizo

    2016-01-01

    Full text: The EMA beamline (Extreme condition X-ray Methods of Analysis) is one of the hard x-ray undulator beamlines within the first phase of the new synchrotron source in Brazil (Sirius project). This beamline is thought to make a difference where a high brilliance (high flux of up to 2 x 10 14 photons/sec with beam size down to 0.5 x 0.5 μm 2 ) is essential, which is the case for extreme pressures that require small focus and time-resolved that require high photon flux. With that in mind we propose the beamline to have two experimental hutches to cover most of the extreme condition techniques today employed at synchrotron laboratories worldwide. These two stations are thought to provide the general infrastructure for magnets and lasers experiments, which may evolve as new scientific problems appear. In addition to the hutches, support laboratories will be strongly linked and supportive to the experiments at the beamline, covering high pressure instrumentations using diamond anvil cells and pump-and-probe requirements for ultrafast and high power lasers. Along these lines, we will describe the following techniques covered at this beamline: magnetic spectroscopy (XMCD) and scattering (XRMS) under high pressure and very low temperature in order to fully probe both ferromagnetic and antiferromagnetic materials and the dependence with pressure; extreme pressure and temperature XRD and XAS experiments using very small diamond culet anvils and high power lasers. (author)

  2. EMA beamline at SIRIUS: extreme condition X-ray methods of analysis

    Energy Technology Data Exchange (ETDEWEB)

    Souza Neto, Narcizo, E-mail: narcizo.souza@lnls.br [Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP (Brazil)

    2016-07-01

    Full text: The EMA beamline (Extreme condition X-ray Methods of Analysis) is one of the hard x-ray undulator beamlines within the first phase of the new synchrotron source in Brazil (Sirius project). This beamline is thought to make a difference where a high brilliance (high flux of up to 2 x 10{sup 14} photons/sec with beam size down to 0.5 x 0.5 μm{sup 2}) is essential, which is the case for extreme pressures that require small focus and time-resolved that require high photon flux. With that in mind we propose the beamline to have two experimental hutches to cover most of the extreme condition techniques today employed at synchrotron laboratories worldwide. These two stations are thought to provide the general infrastructure for magnets and lasers experiments, which may evolve as new scientific problems appear. In addition to the hutches, support laboratories will be strongly linked and supportive to the experiments at the beamline, covering high pressure instrumentations using diamond anvil cells and pump-and-probe requirements for ultrafast and high power lasers. Along these lines, we will describe the following techniques covered at this beamline: magnetic spectroscopy (XMCD) and scattering (XRMS) under high pressure and very low temperature in order to fully probe both ferromagnetic and antiferromagnetic materials and the dependence with pressure; extreme pressure and temperature XRD and XAS experiments using very small diamond culet anvils and high power lasers. (author)

  3. Heavy metals analysis in fishes by the X-ray fluorescence method

    International Nuclear Information System (INIS)

    Perez Novara, Ana Ma.

    1986-04-01

    Among the sources of contamination in human beings we find ingestion of heavy metals. As it is common practice to pour industrial wastes in waters where fishes feed, some toxic elements present in water may pass to human beings through ingestion. It is therefore important to determine the concentrations of heavy metals present in fishes, mainly in those living in waters close to industrial zones or villages. Concentrations of heavy metals in tissue of fishes amount to ppm, hence making necessary the use of very sensitive analytical techniques which do not require a too complex preparation of the sample in order to avoid the loss or contamination of interesting elements of analysis while handling them, thus falsifying the results. The X-Ray Fluorescence method covers these requirements and is not destructive nor multi-elemental. The development of the technique of element analysis in fishes by X-Ray Fluorescence comprised several aspects. from sampling and storage to quantification, specially stressing the preparation of samples. The work was carried out with a Si-Li detector/monitor for solid state and associated electronic equipment. Cd-109 and Pu-238 sources were used to produce excitation, detection limits near 1 ppm were obtained in the majority of elements the technique attained for the analysis of this kind of samples fulfills the celerity, precision, accuracy, and sensitivity requirements. (author)

  4. A software-based x-ray scatter correction method for breast tomosynthesis

    International Nuclear Information System (INIS)

    Jia Feng, Steve Si; Sechopoulos, Ioannis

    2011-01-01

    Purpose: To develop a software-based scatter correction method for digital breast tomosynthesis (DBT) imaging and investigate its impact on the image quality of tomosynthesis reconstructions of both phantoms and patients. Methods: A Monte Carlo (MC) simulation of x-ray scatter, with geometry matching that of the cranio-caudal (CC) view of a DBT clinical prototype, was developed using the Geant4 toolkit and used to generate maps of the scatter-to-primary ratio (SPR) of a number of homogeneous standard-shaped breasts of varying sizes. Dimension-matched SPR maps were then deformed and registered to DBT acquisition projections, allowing for the estimation of the primary x-ray signal acquired by the imaging system. Noise filtering of the estimated projections was then performed to reduce the impact of the quantum noise of the x-ray scatter. Three dimensional (3D) reconstruction was then performed using the maximum likelihood-expectation maximization (MLEM) method. This process was tested on acquisitions of a heterogeneous 50/50 adipose/glandular tomosynthesis phantom with embedded masses, fibers, and microcalcifications and on acquisitions of patients. The image quality of the reconstructions of the scatter-corrected and uncorrected projections was analyzed by studying the signal-difference-to-noise ratio (SDNR), the integral of the signal in each mass lesion (integrated mass signal, IMS), and the modulation transfer function (MTF). Results: The reconstructions of the scatter-corrected projections demonstrated superior image quality. The SDNR of masses embedded in a 5 cm thick tomosynthesis phantom improved 60%-66%, while the SDNR of the smallest mass in an 8 cm thick phantom improved by 59% (p < 0.01). The IMS of the masses in the 5 cm thick phantom also improved by 15%-29%, while the IMS of the masses in the 8 cm thick phantom improved by 26%-62% (p < 0.01). Some embedded microcalcifications in the tomosynthesis phantoms were visible only in the scatter

  5. Investigation of radiation absorption and X-ray fluorescence properties of medical imaging scintillators by Monte Carlo methods

    International Nuclear Information System (INIS)

    Nikolopoulos, D.; Kandarakis, I.; Cavouras, D.; Valais, I.; Linardatos, D.; Michail, C.; David, S.; Gaitanis, A.; Nomicos, C.; Louizi, A.

    2006-01-01

    X-ray absorption and X-ray fluorescence properties of medical imaging scintillating screens were studied by Monte Carlo methods as a function of the incident photon energy and screen-coating thickness. The scintillating materials examined were Gd 2 O 2 S (GOS) Gd 2 SiO 5 (GSO) YAlO 3 (YAP), Y 3 Al 5 O 12 (YAG), LuSiO 5 (LSO), LuAlO 3 (LuAP) and ZnS. Monoenergetic photon exposures were modeled in the range from 10 to 100 keV. The corresponding ranges of coating thicknesses of the investigated scintillating screens ranged up to 200 mg cm -2 . Results indicated that X-ray absorption and X-ray fluorescence are affected by the incident photon energy and the screen's coating thickness. Regarding incident photon energy, this X-ray absorption and fluorescence was found to exhibit very intense changes near the corresponding K edge of the heaviest element in the screen's scintillating material. Regarding coating thickness, thicker screens exhibited higher X-ray absorption and X-ray fluorescence. Results also indicated that a significant fraction of the generated X-ray fluorescent quanta escape from the scintillating screen. This fraction was found to increase with screen's coating thickness. At the energy range studied, most of the incident photons were found to be absorbed via one-hit photoelectric effect. As a result, the reabsorption of scattered radiation was found to be of rather minor importance; nevertheless this was found to increase with the screen's coating thickness. Differences in X-ray absorption and X-ray fluorescence were found among the various scintillators studied. LSO scintillator was found to be the most attractive material for use in many X-ray imaging applications, exhibiting the best absorption properties in the largest part of the energy range studied. Y-based scintillators were also found to be of significant absorption performance within the low energy ranges

  6. Temperature gradient method for lipid phase diagram construction using time-resolved x-ray diffraction

    International Nuclear Information System (INIS)

    Caffrey, M.; Hing, F.S.

    1987-01-01

    A method that enables temperature-composition phase diagram construction at unprecedented rates is described and evaluated. The method involves establishing a known temperature gradient along the length of a metal rod. Samples of different compositions contained in long, thin-walled capillaries are positioned lengthwise on the rod and equilibrated such that the temperature gradient is communicated into the sample. The sample is then moved through a focused, monochromatic synchrotron-derived x-ray beam and the image-intensified diffraction pattern from the sample is recorded on videotape continuously in live-time as a function of position and, thus, temperature. The temperature at which the diffraction pattern changes corresponds to a phase boundary, and the phase(s) existing (coexisting) on either side of the boundary can be identified on the basis of the diffraction pattern. Repeating the measurement on samples covering the entire composition range completes the phase diagram. These additional samples can be conveniently placed at different locations around the perimeter of the cylindrical rod and rotated into position for diffraction measurement. Temperature-composition phase diagrams for the fully hydrated binary mixtures, dimyristoylphosphatidylcholine (DMPC)/dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE)/DPPC, have been constructed using the new temperature gradient method. They agree well with and extend the results obtained by other techniques. In the DPPE/DPPC system structural parameters as a function of temperature in the various phases including the subgel phase are reported. The potential limitations of this steady-state method are discussed

  7. Application of x-ray fluorescence (XRF) absolute analysis method for silica refractories

    International Nuclear Information System (INIS)

    Asakura, Hideo; Yamada, Yasujiro; Kansai, Kouhei; Tomatsu, Ichirou; Murata, Mamoru

    2015-01-01

    X-ray fluorescence (XRF) analysis is a rapid and precise quantitative analytical method for the determination of major and trace elements in many industries and academics. XRF analytical values are relative due to the use of the calibration curves calculated from measuring the reference standard materials such as Japanese Refractory Reference Materials (JRRM) series with certified values determined by wet chemical analysis. The development of the XRF analytical method from relative to absolute analysis will help much to determine the absolute values of samples from the fields where reference standard samples have not been prepared, and thus can be applied widely in many industries. The implement of the absolute XRF analysis for silica refractories requires high purity reagents and/or reference standard solution for the binary basic calibration curve, and theoretical matrix correction coefficients for the multi-components silica refractories analysis. The reproducibility and repeatability of this method for Al 2 O 3 5 mass% sample were 0.009 and 0.006 mass% in Al 2 O 3 and showed better values that those of ICP-AES recognized as an absolute method in JIS R 2212-2, which yielded 0.028 and 0.031 mass%, respectively. The XRF absolute analysis for JRRM 200 series, 201a and 205a does not show a bias but coincides with their certified values. (author)

  8. Powder X-ray diffraction method for the quantification of cocrystals in the crystallization mixture.

    Science.gov (United States)

    Padrela, Luis; de Azevedo, Edmundo Gomes; Velaga, Sitaram P

    2012-08-01

    The solid state purity of cocrystals critically affects their performance. Thus, it is important to accurately quantify the purity of cocrystals in the final crystallization product. The aim of this study was to develop a powder X-ray diffraction (PXRD) quantification method for investigating the purity of cocrystals. The method developed was employed to study the formation of indomethacin-saccharin (IND-SAC) cocrystals by mechanochemical methods. Pure IND-SAC cocrystals were geometrically mixed with 1:1 w/w mixture of indomethacin/saccharin in various proportions. An accurately measured amount (550 mg) of the mixture was used for the PXRD measurements. The most intense, non-overlapping, characteristic diffraction peak of IND-SAC was used to construct the calibration curve in the range 0-100% (w/w). This calibration model was validated and used to monitor the formation of IND-SAC cocrystals by liquid-assisted grinding (LAG). The IND-SAC cocrystal calibration curve showed excellent linearity (R(2) = 0.9996) over the entire concentration range, displaying limit of detection (LOD) and limit of quantification (LOQ) values of 1.23% (w/w) and 3.74% (w/w), respectively. Validation results showed excellent correlations between actual and predicted concentrations of IND-SAC cocrystals (R(2) = 0.9981). The accuracy and reliability of the PXRD quantification method depend on the methods of sample preparation and handling. The crystallinity of the IND-SAC cocrystals was higher when larger amounts of methanol were used in the LAG method. The PXRD quantification method is suitable and reliable for verifying the purity of cocrystals in the final crystallization product.

  9. Use of hydroxyapatite prepared by sol-gel method for gamma ray and electron beam dosimetry

    International Nuclear Information System (INIS)

    Hajiloo, N.; Ziaie, F.; Hesami, M.

    2011-01-01

    In this research, radiation dosimetry was made through measuring free radicals induced in synthetic hydroxyapatite using EPR spectroscopy. At the first step, the hydroxyapatite nano-powders were synthesized via sol-gel method. The produced powders were passed through a thermal treatment, weighted and packed. Then, the samples were irradiated at different dose rates using 60 Co γ-ray and 10 MeV electron beam radiation at a high dose range. The hydroxyapatite signal intensity of hydroxyapatite samples were measured at room temperature in the air. Subsequently, the variations of the EPR signal intensities were constructed as peak-to-peak signal amplitude and were compared with alanine and bone powder samples. The results showed that the EPR signal intensity of the hydroxyapatite samples are several times higher than alanine and bone powder and are saturated at the higher dose rates in comparison with other species.

  10. The two-wave X-ray field calculated by means of integral-equation methods

    International Nuclear Information System (INIS)

    Bremer, J.

    1984-01-01

    The problem of calculating the two-wave X-ray field on the basis of the Takagi-Taupin equations is discussed for the general case of curved lattice planes. A two-dimensional integral equation which incorporates the nature of the incoming radiation, the form of the crystal/vacuum boundary, and the curvature of the structure, is deduced. Analytical solutions for the symmetrical Laue case with incoming plane waves are obtained directly for perfect crystals by means of iteration. The same method permits a simple derivation of the narrow-wave Laue and Bragg cases. Modulated wave fronts are discussed, and it is shown that a cut-off in the width of an incoming plane wave leads to lateral oscillations which are superimposed on the Pendelloesung fringes. Bragg and Laue shadow fields are obtained. The influence of a non-zero kernel is discussed and a numerical procedure for calculating wave amplitudes in curved crystals is presented. (Auth.)

  11. Determining sulfur in metallurgical coke by the X-ray fluorescent method

    Energy Technology Data Exchange (ETDEWEB)

    Sofilic, T.; Kesic-Racan, M.; Sindler, M.; Sokolean, D.

    1979-01-01

    A method is described of X-ray fluorescent analysis for current determination of sulfur in the concentration range of 0.5-1.16% in metallurgical coke. To do this, the analyzed material (coke) is ground to a particle size of 200 mu and mixed in a 1:1 ratio with an organic binder (soluble starch). The mixture is briquetted in meshes of a certain size under a pressure of 25 tons/cm/sub 2/. The tablets obtained are analyzed in a Phillips spectrometer with a Cr anticathode. The presence is noted of a linear dependence between the S content and the instrument reading; the correlation factor is 0.91; the mean detection error, 0.0596.

  12. A method for the quantitative analysis of heavy elements by X-ray fluorescence

    International Nuclear Information System (INIS)

    Souza Caillaux, Z. de

    1981-01-01

    A study of quantitative analysis methodology by X-ray fluorescence analysis is presented. With no damage to precision it makes possible an analysis of heavy elements in samples with the form and texture as they present themselves. Some binary alloys were examined such as: FeCo; CuNi; CuZn; AgCd; AgPd; AuPt e PtIr. The possibility of application of this method is based on the compromise solutIon of wave lengths and the intensity of the homologous emission and absorption edges of constituents with the quantic efficiency of the detector, the dispersion and the wave lenght resolution of crystal analyser, and the uniformity of the excitation intensity. (Author) [pt

  13. Particle induced X-ray emission and complementary nuclear methods for trace element determination; Plenary lecture

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, S A.E. [Lund Univ. (Sweden). Dept. of Nuclear Physics

    1992-03-01

    In this review the state-of-the-art of particle induced X-ray emission (PIXE) methods for the determination of trace elements is described. The developmental work has mostly been carried out in nuclear physics laboratories, where accelerators are available, but now the increased interest has led to the establishment of other dedicated PIXE facilities. The reason for this interest is the versatility, high sensitivity and multi-element capability of PIXE analysis. A further very important advantage is that PIXE can be combined with the microbeam technique, which makes elemental mapping with a spatial resolution of about 1 {mu}m possible. As a technique, PIXE can also be combined with other nuclear reactions such as elastic scattering and particle-induced gamma emission, so that light elements can be determined. The usefulness of PIXE is illustrated by a number of typical applications in biology, medicine, geology, air pollution research, archaeology and the arts. (author).

  14. Accelerated gradient methods for the x-ray imaging of solar flares

    Science.gov (United States)

    Bonettini, S.; Prato, M.

    2014-05-01

    In this paper we present new optimization strategies for the reconstruction of x-ray images of solar flares by means of the data collected by the Reuven Ramaty high energy solar spectroscopic imager. The imaging concept of the satellite is based on rotating modulation collimator instruments, which allow the use of both Fourier imaging approaches and reconstruction techniques based on the straightforward inversion of the modulated count profiles. Although in the last decade, greater attention has been devoted to the former strategies due to their very limited computational cost, here we consider the latter model and investigate the effectiveness of different accelerated gradient methods for the solution of the corresponding constrained minimization problem. Moreover, regularization is introduced through either an early stopping of the iterative procedure, or a Tikhonov term added to the discrepancy function by means of a discrepancy principle accounting for the Poisson nature of the noise affecting the data.

  15. Forensic classification of counterfeit banknote paper by X-ray fluorescence and multivariate statistical methods.

    Science.gov (United States)

    Guo, Hongling; Yin, Baohua; Zhang, Jie; Quan, Yangke; Shi, Gaojun

    2016-09-01

    Counterfeiting of banknotes is a crime and seriously harmful to economy. Examination of the paper, ink and toners used to make counterfeit banknotes can provide useful information to classify and link different cases in which the suspects use the same raw materials. In this paper, 21 paper samples of counterfeit banknotes seized from 13 cases were analyzed by wavelength dispersive X-ray fluorescence. After measuring the elemental composition in paper semi-quantitatively, the normalized weight percentage data of 10 elements were processed by multivariate statistical methods of cluster analysis and principle component analysis. All these paper samples were mainly classified into 3 groups. Nine separate cases were successfully linked. It is demonstrated that elemental composition measured by XRF is a useful way to compare and classify papers used in different cases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. A method for measuring the time structure of synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Moses, W.W.; Derenzo, S.E.

    1989-08-01

    We describe a method employing a plastic scintillator coupled to a fast photomultiplier tube to generate a timing pulse from the x-ray bursts emitted from a synchrotron radiation source. This technique is useful for performing synchrotron experiments where detailed knowledge of the timing distribution is necessary, such as time resolved spectroscopy or fluorescence lifetime experiments. By digitizing the time difference between the timing signal generated on one beam crossing with the timing signal generated on the next beam crossing, the time structure of a synchrotron beam can be analyzed. Using this technique, we have investigated the single bunch time structure at the National Synchrotron Light Source (NSLS) during pilot runs in January, 1989, and found that the majority of the beam (96%) is contained in one rf bucket, while the remainder of the beam (4%) is contained in satellite rf buckets preceeding and following the main rf bucket by 19 ns. 1 ref., 4 figs

  17. Calculational methods for estimating skin dose from electrons in Co-60 gamma-ray beams

    International Nuclear Information System (INIS)

    Higgins, P.D.; Sibata, C.H.; Attix, F.H.; Paliwal, B.R.

    1983-01-01

    Several methods have been employed to calculate the relative contribution to skin dose due to scattered electrons in Co-60 gamma-ray beams. Either the Klein-Nishina differential scattering probability is employed to determine the number and initial energy of electrons scattered into the direction of a detector, or a Gaussian approximation is used to specify the surface distribution of initial pencil electron beams created by parallel or diverging photon fields. Results of these calculations are compared with experimental data. In addition, that fraction of relative surface dose resulting from photon interactions in air alone is estimated and compared with data extrapolated from measurements at large source-surface distance (SSD). The contribution to surface dose from electrons generated in air is 50% or more of the total skin dose for SSDs greater than 80 cm

  18. Calculational methods for estimating skin dose from electrons in Co-60 gamma-ray beams

    International Nuclear Information System (INIS)

    Higgins, P.D.; Sibata, C.H.; Attix, F.H.; Paliwal, B.R.

    1983-01-01

    Several methods have been employed to calculate the relative contribution to skin dose due to scattered electrons in Co-60 γ-ray beams. Either the Klein--Nishina differential scattering probability is employed to determine the number and initial energy of electrons scattered into the direction of a detector, or a Gaussian approximation is used to specify the surface distribution of initial pencil electron beams created by parallel or diverging photon fields. Results of these calculations are compared with experimental data. In addition, that fraction of relative surface dose resulting from photon interactions in air alone is estimated and compared with data extrapolated from measurements at large source--surface distance (SSD). The contribution to surface dose from electrons generated in air is 50% or more of the total skin dose for SSDs greater than 80 cm

  19. [Near infrared distance sensing method for Chang'e-3 alpha particle X-ray spectrometer].

    Science.gov (United States)

    Liang, Xiao-Hua; Wu, Ming-Ye; Wang, Huan-Yu; Peng, Wen-Xi; Zhang, Cheng-Mo; Cui, Xing-Zhu; Wang, Jin-Zhou; Zhang, Jia-Yu; Yang, Jia-Wei; Fan, Rui-Rui; Gao, Min; Liu, Ya-Qing; Zhang, Fei; Dong, Yi-Fan; Guo, Dong-Ya

    2013-05-01

    Alpha particle X-ray spectrometer (APXS) is one of the payloads of Chang'E-3 lunar rover, the scientific objective of which is in-situ observation and off-line analysis of lunar regolith and rock. Distance measurement is one of the important functions for APXS to perform effective detection on the moon. The present paper will first give a brief introduction to APXS, and then analyze the specific requirements and constraints to realize distance measurement, at last present a new near infrared distance sensing algorithm by using the inflection point of response curve. The theoretical analysis and the experiment results verify the feasibility of this algorithm. Although the theoretical analysis shows that this method is not sensitive to the operating temperature and reflectance of the lunar surface, the solar infrared radiant intensity may make photosensor saturation. The solutions are reducing the gain of device and avoiding direct exposure to sun light.

  20. The theoretical study of full spectrum analysis method for airborne gamma-ray spectrometric data

    International Nuclear Information System (INIS)

    Ni Weichong

    2011-01-01

    Spectra of airborne gamma-ray spectrometry was found to be the synthesis of spectral components of radioelement sources by analyzing the constitution of radioactive sources for airborne gamma-ray spectrometric survey and establishing the models of gamma-ray measurement. The mathematical equation for analysising airborne gamma-ray full spectrometric data can be expressed into matrix and related expansions were developed for the mineral resources exploration, environmental radiation measurement, nuclear emergency monitoring, and so on. Theoretical study showed that the atmospheric radon could be directly computed by airborne gamma-ray spectrometric data with full spectrum analysis without the use of the accessional upward-looking detectors. (authors)

  1. Method and apparatus for neutron induced gamma ray logging for lithology identification

    International Nuclear Information System (INIS)

    Oliver, D.W.; Culver, R.B.

    1981-01-01

    The patent describes a neutron-gamma well logging technique which can distinguish between sandstone and limestone formations irrespective of water salinity in the formation. The formation surrounding a borehole is irradiated by fast neutrons and the resulting gamma rays are counted. The gamma rays are converted to electrical signals in three distinct steps; the first two signals result from gamma rays associated with calcium content of the formation and the third signal from gamma rays associated with silicon content. Gamma rays resulting from irradiation of calcium are counted at two non-contiguous energy bands. (O.T.)

  2. Comparison of ray methods with the exact solution in the 1-D anisotropic "simplified twisted crystal" model

    Czech Academy of Sciences Publication Activity Database

    Bulant, P.; Klimeš, L.; Pšenčík, Ivan; Vavryčuk, Václav

    2004-01-01

    Roč. 48, č. 4 (2004), s. 675-688 ISSN 0039-3169 R&D Projects: GA ČR GA205/04/1104; GA AV ČR IAA3012309; GA AV ČR KSK3012103 Institutional research plan: CEZ:AV0Z3012916 Keywords : coupling ray theory * quasi-isotropic approximation * ray methods Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.447, year: 2004

  3. Improvement of high-fold gamma-ray data processing: the spherical gate method

    CERN Document Server

    Theisen, C; Stezowski, O; Vivien, J P

    1999-01-01

    A new method for optimizing the processing of events from a highly efficient large array gamma-ray detector is described in this article. The spherical gates technique, developed to project high-fold events, consists of optimizing n-dimensional gate shape as a function of peak width and shape of each detector. Formulas in closed form are proposed for determining the projected statistics from coincidence fold and peak shape and for estimating the increased quality of projected spectra. This procedure has been tested on high-fold, high statistics data sets including superdeformed cascades. Compared to the classical 'square-gate' technique, better peak-to-background ratios as well as a reduction in fluctuations are observed. A quality parameter is defined to characterize the optimal parameter set. This method leads roughly to a gain in spectral quality equivalent of one fold. It is also shown that the efficiency of the method increases with coincidence fold. This should be particularly suited for future higher-f...

  4. Dose calculation method with 60-cobalt gamma rays in total body irradiation

    International Nuclear Information System (INIS)

    Scaff, Luiz Alberto Malaguti

    2001-01-01

    Physical factors associated to total body irradiation using 60 Co gamma rays beams, were studied in order to develop a calculation method of the dose distribution that could be reproduced in any radiotherapy center with good precision. The method is based on considering total body irradiation as a large and irregular field with heterogeneities. To calculate doses, or doses rates, of each area of interest (head, thorax, thigh, etc.), scattered radiation is determined. It was observed that if dismagnified fields were considered to calculate the scattered radiation, the resulting values could be applied on a projection to the real size to obtain the values for dose rate calculations. In a parallel work it was determined the variation of the dose rate in the air, for the distance of treatment, and for points out of the central axis. This confirm that the use of the inverse square law is not valid. An attenuation curve for a broad beam was also determined in order to allow the use of absorbers. In this work all the adapted formulas for dose rate calculations in several areas of the body are described, as well time/dose templates sheets for total body irradiation. The in vivo dosimetry, proved that either experimental or calculated dose rate values (achieved by the proposed method), did not have significant discrepancies. (author)

  5. Standard test methods for chemical analysis of ceramic whiteware materials using wavelength dispersive X-Ray fluorescence spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover the determination of ten major elements (SiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, TiO2, P2O5, MnO, and LOI in ceramic whitewares clays and minerals using wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The sample is first ignited, then fused with lithium tetraborate and the resultant glass disc is introduced into a wavelength dispersive X-ray spectrometer. The disc is irradiated with X-rays from an X-ray tube. X-ray photons emitted by the elements in the samples are counted and concentrations determined using previously prepared calibration standards. (1) In addition to 10 major elements, the method provides a gravimetric loss-on-ignition. Note 1—Much of the text of this test method is derived directly from Major element analysis by wavelength dispersive X-ray fluorescence spectrometry, included in Ref (1). 1.2 Interferences, with analysis by WDXRF, may result from mineralogical or other structural effects, line overlaps, and matrix effects. The structure of the...

  6. Method comparison of ultrasound and kilovoltage x-ray fiducial marker imaging for prostate radiotherapy targeting

    International Nuclear Information System (INIS)

    Fuller, Clifton David; Jr, Charles R Thomas; Schwartz, Scott; Golden, Nanalei; Ting, Joe; Wong, Adrian; Erdogmus, Deniz; Scarbrough, Todd J

    2006-01-01

    Several measurement techniques have been developed to address the capability for target volume reduction via target localization in image-guided radiotherapy; among these have been ultrasound (US) and fiducial marker (FM) software-assisted localization. In order to assess interchangeability between methods, US and FM localization were compared using established techniques for determination of agreement between measurement methods when a 'gold-standard' comparator does not exist, after performing both techniques daily on a sequential series of patients. At least 3 days prior to CT simulation, four gold seeds were placed within the prostate. FM software-assisted localization utilized the ExacTrac X-Ray 6D (BrainLab AG, Germany) kVp x-ray image acquisition system to determine prostate position; US prostate targeting was performed on each patient using the SonArray (Varian, Palo Alto, CA). Patients were aligned daily using laser alignment of skin marks. Directional shifts were then calculated by each respective system in the X, Y and Z dimensions before each daily treatment fraction, previous to any treatment or couch adjustment, as well as a composite vector of displacement. Directional shift agreement in each axis was compared using Altman-Bland limits of agreement, Lin's concordance coefficient with Partik's grading schema, and Deming orthogonal bias-weighted correlation methodology. 1019 software-assisted shifts were suggested by US and FM in 39 patients. The 95% limits of agreement in X, Y and Z axes were ±9.4 mm, ±11.3 mm and ±13.4, respectively. Three-dimensionally, measurements agreed within 13.4 mm in 95% of all paired measures. In all axes, concordance was graded as 'poor' or 'unacceptable'. Deming regression detected proportional bias in both directional axes and three-dimensional vectors. Our data suggest substantial differences between US and FM image-guided measures and subsequent suggested directional shifts. Analysis reveals that the vast majority of

  7. Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume

    International Nuclear Information System (INIS)

    Malkov, Serghei; Wang, Jeff; Kerlikowske, Karla; Cummings, Steven R.; Shepherd, John A.

    2009-01-01

    Purpose: This study describes the design and characteristics of a highly accurate, precise, and automated single-energy method to quantify percent fibroglandular tissue volume (%FGV) and fibroglandular tissue volume (FGV) using digital screening mammography. Methods: The method uses a breast tissue-equivalent phantom in the unused portion of the mammogram as a reference to estimate breast composition. The phantom is used to calculate breast thickness and composition for each image regardless of x-ray technique or the presence of paddle tilt. The phantom adheres to the top of the mammographic compression paddle and stays in place for both craniocaudal and mediolateral oblique screening views. We describe the automated method to identify the phantom and paddle orientation with a three-dimensional reconstruction least-squares technique. A series of test phantoms, with a breast thickness range of 0.5-8 cm and a %FGV of 0%-100%, were made to test the accuracy and precision of the technique. Results: Using test phantoms, the estimated repeatability standard deviation equaled 2%, with a ±2% accuracy for the entire thickness and density ranges. Without correction, paddle tilt was found to create large errors in the measured density values of up to 7%/mm difference from actual breast thickness. This new density measurement is stable over time, with no significant drifts in calibration noted during a four-month period. Comparisons of %FGV to mammographic percent density and left to right breast %FGV were highly correlated (r=0.83 and 0.94, respectively). Conclusions: An automated method for quantifying fibroglandular tissue volume has been developed. It exhibited good accuracy and precision for a broad range of breast thicknesses, paddle tilt angles, and %FGV values. Clinical testing showed high correlation to mammographic density and between left and right breasts.

  8. The use of x-ray pulsar-based navigation method for interplanetary flight

    Science.gov (United States)

    Yang, Bo; Guo, Xingcan; Yang, Yong

    2009-07-01

    As interplanetary missions are increasingly complex, the existing unique mature interplanetary navigation method mainly based on radiometric tracking techniques of Deep Space Network can not meet the rising demands of autonomous real-time navigation. This paper studied the applications for interplanetary flights of a new navigation technology under rapid development-the X-ray pulsar-based navigation for spacecraft (XPNAV), and valued its performance with a computer simulation. The XPNAV is an excellent autonomous real-time navigation method, and can provide comprehensive navigation information, including position, velocity, attitude, attitude rate and time. In the paper the fundamental principles and time transformation of the XPNAV were analyzed, and then the Delta-correction XPNAV blending the vehicles' trajectory dynamics with the pulse time-of-arrival differences at nominal and estimated spacecraft locations within an Unscented Kalman Filter (UKF) was discussed with a background mission of Mars Pathfinder during the heliocentric transferring orbit. The XPNAV has an intractable problem of integer pulse phase cycle ambiguities similar to the GPS carrier phase navigation. This article innovatively proposed the non-ambiguity assumption approach based on an analysis of the search space array method to resolve pulse phase cycle ambiguities between the nominal position and estimated position of the spacecraft. The simulation results show that the search space array method are computationally intensive and require long processing time when the position errors are large, and the non-ambiguity assumption method can solve ambiguity problem quickly and reliably. It is deemed that autonomous real-time integrated navigation system of the XPNAV blending with DSN, celestial navigation, inertial navigation and so on will be the development direction of interplanetary flight navigation system in the future.

  9. Integration of Monte-Carlo ray tracing with a stochastic optimisation method: application to the design of solar receiver geometry.

    Science.gov (United States)

    Asselineau, Charles-Alexis; Zapata, Jose; Pye, John

    2015-06-01

    A stochastic optimisation method adapted to illumination and radiative heat transfer problems involving Monte-Carlo ray-tracing is presented. A solar receiver shape optimisation case study illustrates the advantages of the method and its potential: efficient receivers are identified using a moderate computational cost.

  10. Quantitative analysis of concrete using portable x-ray fluorescence: Method development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Washington, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Narrows, William [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Msgwood, Leroy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-27

    During Decommissioning and Demolition (D&D) activities at SRS, it is important that the building be screened for radionuclides and heavy metals to ensure that the proper safety and disposal metrics are in place. A major source of contamination at DOE facilities is the accumulation of mercury contamination, from nuclear material processing and Liquid Waste System (LWS). This buildup of mercury could possibly cause harm to any demolition crew or the environment should this material be released. The current standard method is to take core samples in various places in the facility and use X-ray fluorescence (XRF) to detect the contamination. This standard method comes with a high financial value due to the security levels of these sample facilities with unknown contamination levels. Here in we propose the use of portable XRF units to detect for this contamination on-site. To validate this method, the instrument has to be calibrated to detect the heavy metal contamination, be both precise with the known elemental concentrations and consistent with its actual results of a sample concrete and pristine contaminant, and be able to detect changes in the sample concrete’s composition. After receiving the various concrete samples with their compositions found by a XRF wave-dispersive method, the calibration factor’s linear regressions were adjusted to give the baseline concentration of the concrete with no contamination. Samples of both concrete and concrete/flyash were evaluated; their standard deviations revealed that the measurements were consistent with the known composition. Finally, the samples were contaminated with different concentrations of sodium tungsten dihydrate, allowed to air dry, and measured. When the contaminated samples were analyzed, the heavy metal contamination was seen within the spectrum of the instrument, but there was not a trend of quantification based on the concentration of the solution.

  11. A reconstruction method for cone-beam differential x-ray phase-contrast computed tomography.

    Science.gov (United States)

    Fu, Jian; Velroyen, Astrid; Tan, Renbo; Zhang, Junwei; Chen, Liyuan; Tapfer, Arne; Bech, Martin; Pfeiffer, Franz

    2012-09-10

    Most existing differential phase-contrast computed tomography (DPC-CT) approaches are based on three kinds of scanning geometries, described by parallel-beam, fan-beam and cone-beam. Due to the potential of compact imaging systems with magnified spatial resolution, cone-beam DPC-CT has attracted significant interest. In this paper, we report a reconstruction method based on a back-projection filtration (BPF) algorithm for cone-beam DPC-CT. Due to the differential nature of phase contrast projections, the algorithm restrains from differentiation of the projection data prior to back-projection, unlike BPF algorithms commonly used for absorption-based CT data. This work comprises a numerical study of the algorithm and its experimental verification using a dataset measured with a three-grating interferometer and a micro-focus x-ray tube source. Moreover, the numerical simulation and experimental results demonstrate that the proposed method can deal with several classes of truncated cone-beam datasets. We believe that this feature is of particular interest for future medical cone-beam phase-contrast CT imaging applications.

  12. Comparison of methods for suppressing edge and aliasing artefacts in iterative x-ray CT reconstruction

    International Nuclear Information System (INIS)

    Zbijewski, Wojciech; Beekman, Freek J

    2006-01-01

    X-ray CT images obtained with iterative reconstruction (IR) can be hampered by the so-called edge and aliasing artefacts, which appear as interference patterns and severe overshoots in the areas of sharp intensity transitions. Previously, we have demonstrated that these artefacts are caused by discretization errors during the projection simulation step in IR. Although these errors are inherent to IR, they can be adequately suppressed by reconstruction on an image grid that is finer than that typically used for analytical methods such as filtered back-projection. Two other methods that may prevent edge artefacts are: (i) smoothing the projections prior to reconstruction or (ii) using an image representation different from voxels; spherically symmetric Kaiser-Bessel functions are a frequently employed example of such a representation. In this paper, we compare reconstruction on a fine grid with the two above-mentioned alternative strategies for edge artefact reduction. We show that the use of a fine grid results in a more adequate suppression of artefacts than the smoothing of projections or using the Kaiser-Bessel image representation

  13. A fast pulse phase estimation method for X-ray pulsar signals based on epoch folding

    Directory of Open Access Journals (Sweden)

    Xue Mengfan

    2016-06-01

    Full Text Available X-ray pulsar-based navigation (XPNAV is an attractive method for autonomous deep-space navigation in the future. The pulse phase estimation is a key task in XPNAV and its accuracy directly determines the navigation accuracy. State-of-the-art pulse phase estimation techniques either suffer from poor estimation accuracy, or involve the maximization of generally non-convex object function, thus resulting in a large computational cost. In this paper, a fast pulse phase estimation method based on epoch folding is presented. The statistical properties of the observed profile obtained through epoch folding are developed. Based on this, we recognize the joint probability distribution of the observed profile as the likelihood function and utilize a fast Fourier transform-based procedure to estimate the pulse phase. Computational complexity of the proposed estimator is analyzed as well. Experimental results show that the proposed estimator significantly outperforms the currently used cross-correlation (CC and nonlinear least squares (NLS estimators, while significantly reduces the computational complexity compared with NLS and maximum likelihood (ML estimators.

  14. A method for describing the doses delivered by transmission x-ray computed tomography

    International Nuclear Information System (INIS)

    Shope, T.B.; Gagne, R.M.; Johnson, G.C.

    1981-01-01

    A method for describing the absorbed dose delivered by x-ray transmission computed tomography (CT) is proposed which provides a means to characterize the dose resulting from CT procedures consisting of a series of adjacent scans. The dose descriptor chosen is the average dose at several locations in the imaged volume of the central scan of the series. It is shown that this average dose, as defined, for locations in the central scan of the series can be obtained from the integral of the dose profile perpendicular to the scan plane at these same locations for a single scan. This method for estimating the average dose from a CT procedure has been evaluated as a function of the number of scans in the multiple scan procedure and location in the dosimetry phantom using single scan dose profiles obtained from five different types of CT systems. For the higher dose regions in the phantoms, the multiple scan dose descriptor derived from the single scan dose profiles overestimates the multiple scan average dose by no more than 10%, provided the procedure consists of at least eight scans

  15. A new method for imaging nuclear threats using cosmic ray muons

    OpenAIRE

    Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Timothy; Aberle, Derek; Green, J. Andrew; McDuff, George G.; Lukić, Zarija; Milner, Edward C.

    2013-01-01

    Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for...

  16. Standard test method for determining the effective elastic parameter for X-ray diffraction measurements of residual stress

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1998-01-01

    1.1 This test method covers a procedure for experimentally determining the effective elastic parameter, Eeff, for the evaluation of residual and applied stresses by X-ray diffraction techniques. The effective elastic parameter relates macroscopic stress to the strain measured in a particular crystallographic direction in polycrystalline samples. Eeff should not be confused with E, the modulus of elasticity. Rather, it is nominally equivalent to E/(1 + ν) for the particular crystallographic direction, where ν is Poisson's ratio. The effective elastic parameter is influenced by elastic anisotropy and preferred orientation of the sample material. 1.2 This test method is applicable to all X-ray diffraction instruments intended for measurements of macroscopic residual stress that use measurements of the positions of the diffraction peaks in the high back-reflection region to determine changes in lattice spacing. 1.3 This test method is applicable to all X-ray diffraction techniques for residual stress measurem...

  17. Fine Output Voltage Control Method considering Time-Delay of Digital Inverter System for X-ray Computed Tomography

    Science.gov (United States)

    Shibata, Junji; Kaneko, Kazuhide; Ohishi, Kiyoshi; Ando, Itaru; Ogawa, Mina; Takano, Hiroshi

    This paper proposes a new output voltage control for an inverter system, which has time-delay and nonlinear load. In the next generation X-ray computed tomography of a medical device (X-ray CT) that uses the contactless power transfer method, the feedback signal often contains time-delay due to AD/DA conversion and error detection/correction time. When the PID controller of the inverter system is received the adverse effects of the time-delay, the controller often has an overshoot and a oscillated response. In order to overcome this problem, this paper proposes a compensation method based on the Smith predictor for an inverter system having a time-delay and the nonlinear loads which are the diode bridge rectifier and X-ray tube. The proposed compensation method consists of the hybrid Smith predictor system based on an equivalent analog circuit and DSP. The experimental results confirm the validity of the proposed system.

  18. Some Applications of X-Ray Based Elemental Analysis Methods for Romanian Gold Minerals Studies

    International Nuclear Information System (INIS)

    Stan, D.; Constantinescu, B.; Pauna, C.; Neacsu, A.; Popescu, G.

    2009-01-01

    The elemental composition of gold, gold minerals and gold associated minerals releases important information's both from scientific (geologic) and economic point of view. In the present work, we focused on samples from Rosia Montana and Musariu ore deposits, from so called T ransylvanian gold of the golden q uadrilateral , Metaliferi Mountains. Our investigation started using optical microscopy. On the sample from Rosia Montana native gold band could be macroscopically seen. Gold occurs also like native gold in carbonate minerals, or associated with galena, sphalerite, chalcopyrite and quartz. The sample from Musariu shows native gold distributed at the border of sphalerite, native gold enclosed and along the margins of sphalerite and native gold between quartz grains. Three X-ray (the emission of characteristic lines spectra for each element present in the sample) based elemental analysis methods were also used: X-Ray Fluorescence (XRF), micro Synchrotron Radiation induced X-Ray Fluorescence (micro-SR-XRF) and micro Proton Induced X-Ray Emission (micro-PIXE). Our XRF methods are based on Xray tube spectrometers: a portable one - X-MET 3000TX and a stationary one - Spectro MIDEX. The two Rosia Montana and Musariu gold samples were studied using the micro-PIXE technique at the AN2000 accelerator of Laboratory Nazionale di Legnaro (LNL), INFN, Italy - maps and point spectra. The experiment was carried out with a 2 MeV proton microbeam (9 μm 2 beam area), maximum beam current 400 pA. The characteristic X-rays were measured with a Canberra HPGe detector (with 180 eV FWHM at 5.9 keV). Complementary experiments on the samples due the improved condition offered by the high energy X-rays, namely -Sb, Sn, Te detection, were performed at BESSY Synchrotron Radiation Facility, Berlin - point spectra. During the experiment, point spectra were acquired at 35 keV, excitation energy, using a spatially resolved synchrotron-radiation XRF setup detected to analyses. The XRF

  19. Mineralogical analysis of clays in hardsetting soil horizons, by X-ray fluorescence and X-ray diffraction using Rietveld method

    International Nuclear Information System (INIS)

    Prandel, L.V.; Saab, S.C.; Brinatti, A.M.; Giarola, N.F.B.; Leite, W.C.; Cassaro, F.A.M.

    2014-01-01

    Diffraction and spectroscopic techniques have been shown to be suitable for obtaining physical and mineralogical properties in polycrystalline soil samples, and also in their precursor compounds. For instance, the X-ray fluorescence (XRF) spectroscopy allows obtaining the elemental composition of an investigated sample, while the X-ray diffraction (XRD) technique permits obtaining qualitative and quantitative composition of the soil minerals through the Rietveld method (RM). In this study Yellow Latosol (Oxisol), Yellow Argisol (Ultisol) and Gray Argisol (Ultisol) soil samples, classified as “hardsetting soils”, extracted from areas located at Northeast and Southeast of Brazilian coast were investigated. The soils and their fractions were analyzed in an EDX-700 and an XRD-6000 (Cu K α radiation). XRF results indicate high percentages of Si and Al, and small percentage of Fe and Ti in the investigated samples. The DRX data and RM indicate that there was a predominance of kaolinite and halloysite minerals (kaolin group minerals) in the clay fractions, which are presumably responsible for the formation of kaolinitic plasma in these soils. Also, the obtained results showed that the XRF, XRD techniques and RM were very helpful for investigating the mineralogical composition of a hardsetting soil. - Highlights: ► Elemental composition of soil samples through X-Ray fluorescence. ► Mineralogical quantification through X-ray diffraction and Rietveld method. ► Oxisol and Ultisol, Brazil ‘Barreiras’ formation. ► High amounts of Si and Al oxides and low amounts of Fe and Ti oxides. ► Predominance of kaolinite in the clay fraction

  20. The application of X-ray fluorescence (XRF) method for the determination chemical composition of glass bath raw materials

    International Nuclear Information System (INIS)

    Werfel, Z.

    1974-01-01

    The estimation of determination accuracy of glass sand, limestone and dolomite compositions by the means of X-ray fluorescence method has been made. The most important advantage of XRF method application is short time of analysis. The preparation time of sample is not longer than 20 minutes, the analysis of single sample is about 1,5 minutes. The comparison of results of determinations by the means of XRF and complexometric methods have been given. (author)

  1. Study on methods of quantitative analysis of the biological thin samples in EM X-ray microanalysis

    International Nuclear Information System (INIS)

    Zhang Detian; Zhang Xuemin; He Kun; Yang Yi; Zhang Sa; Wang Baozhen

    2000-01-01

    Objective: To study the methods of quantitative analysis of the biological thin samples. Methods: Hall theory was used to study the qualitative analysis, background subtraction, peel off overlap peaks; external radiation and aberrance of spectra. Results: The results of reliable qualitative analysis and precise quantitative analysis were achieved. Conclusion: The methods for analysis of the biological thin samples in EM X-ray microanalysis can be used in biomedical research

  2. Reference peak method for analysis of doublets in gamma-ray spectrometry used in neutron activation analysis

    International Nuclear Information System (INIS)

    Wasek, M.; Cichowlas, A.; Sterlinski, S.; Dybczynski, R.

    2000-01-01

    A simple algebraic method for the quantitative analysis of doublets in gamma-ray spectra from HPGe detectors is presented. The calculation algorithm is accomplished using the Microsoft Excel program. The method does not require any assumptions regarding the shape of the peaks in the spectrum. The possibilities of quantitative analysis of doublets of various intensity ration and separation of ots components are discussed in detail. The practical examples proved the usefulness the method also for the analysis of the closed doublets. (author)

  3. Pepsi-SAXS : an adaptive method for rapid and accurate computation of small-angle X-ray scattering profiles

    OpenAIRE

    Grudinin , Sergei; Garkavenko , Maria; Kazennov , Andrei

    2017-01-01

    International audience; A new method called Pepsi-SAXS is presented that calculates small-angle X-ray scattering profiles from atomistic models. The method is based on the multipole expansion scheme and is significantly faster compared with other tested methods. In particular, using the Nyquist–Shannon–Kotelnikov sampling theorem, the multipole expansion order is adapted to the size of the model and the resolution of the experimental data. It is argued that by using the adaptive expansion ord...

  4. The comparative study of contents of zinc and lead in ore samples of Namtu-Bawdwin Mine by wet analysis, X-ray fluorescence and X-ray diffraction methods

    Energy Technology Data Exchange (ETDEWEB)

    Kyaw-Soe,

    1990-05-01

    Lead-zinc ores taken from Namtu-Bawdwin area had been analyzed by wet processes in the Department of Chemistry, 1984. These ore samples have been analyzed by energy dispersive X-ray fluorescence method in the Department of Physics and X-ray diffraction method is also used to determine elements of lead and zinc compounds in these ore samples in the University`s Research Centre. In brief, we study comparatively the contents of lead and zinc and their compounds using the methods of wet processes, X-ray fluorescence and X-ray diffraction. (author).

  5. Spectral-ratio radon background correction method in airborne γ-ray spectrometry based on compton scattering deduction

    International Nuclear Information System (INIS)

    Gu Yi; Xiong Shengqing; Zhou Jianxin; Fan Zhengguo; Ge Liangquan

    2014-01-01

    γ-ray released by the radon daughter has severe impact on airborne γ-ray spectrometry. The spectral-ratio method is one of the best mathematical methods for radon background deduction in airborne γ-ray spectrometry. In this paper, an advanced spectral-ratio method was proposed which deducts Compton scattering ray by the fast Fourier transform rather than tripping ratios, the relationship between survey height and correction coefficient of the advanced spectral-ratio radon background correction method was studied, the advanced spectral-ratio radon background correction mathematic model was established, and the ground saturation model calibrating technology for correction coefficient was proposed. As for the advanced spectral-ratio radon background correction method, its applicability and correction efficiency are improved, and the application cost is saved. Furthermore, it can prevent the physical meaning lost and avoid the possible errors caused by matrix computation and mathematical fitting based on spectrum shape which is applied in traditional correction coefficient. (authors)

  6. Manufacturing method for hard x-ray focusing mirrors with ellipsoidal surface

    International Nuclear Information System (INIS)

    Yumoto, Hirokatsu; Koyama, Takahisa; Ohashi, Haruhiko; Matsuyama, Satoshi; Yamauchi, Kazuto

    2014-01-01

    The aim of this study is to establishing the manufacturing method for hard x-ray nano-focusing mirrors with ellipsoidal surface. Ellipsoidal mirror optics, which can produce point focus with a mirror, has a noticeable feature of a high focusing efficiency, although an ultra-precise surface figure with an accuracy of a few nanometers is required for nano-focusing mirrors. Here, we examined the effectiveness of the manufacturing process for ellipsoidal mirrors, which is consisted of a precision grinding process, a removal process of surface roughness, and a computer-controlled shape correction. The precision processing machine for both a removal of surface roughness and a shape correction was developed. This validated the utility of removing surface roughness with a spatial wavelength of 40 μm, which is the tool mark of the grinding process. The developed process achieved the improvement of surface roughness from 1.6 nm to 0.1 nm (RMS), and the figure correction with a high accuracy of < 10 nm and a spatial resolution of < 2 mm. (author)

  7. About a method for compressing x-ray computed microtomography data

    Science.gov (United States)

    Mancini, Lucia; Kourousias, George; Billè, Fulvio; De Carlo, Francesco; Fidler, Aleš

    2018-04-01

    The management of scientific data is of high importance especially for experimental techniques that produce big data volumes. Such a technique is x-ray computed tomography (CT) and its community has introduced advanced data formats which allow for better management of experimental data. Rather than the organization of the data and the associated meta-data, the main topic on this work is data compression and its applicability to experimental data collected from a synchrotron-based CT beamline at the Elettra-Sincrotrone Trieste facility (Italy) and studies images acquired from various types of samples. This study covers parallel beam geometry, but it could be easily extended to a cone-beam one. The reconstruction workflow used is the one currently in operation at the beamline. Contrary to standard image compression studies, this manuscript proposes a systematic framework and workflow for the critical examination of different compression techniques and does so by applying it to experimental data. Beyond the methodology framework, this study presents and examines the use of JPEG-XR in combination with HDF5 and TIFF formats providing insights and strategies on data compression and image quality issues that can be used and implemented at other synchrotron facilities and laboratory systems. In conclusion, projection data compression using JPEG-XR appears as a promising, efficient method to reduce data file size and thus to facilitate data handling and image reconstruction.

  8. Structural refinement of artificial superlattices by the X-ray diffraction method

    CERN Document Server

    Ishibashi, Y; Tsurumi, T

    1999-01-01

    This paper reports a structural refinement of BaTiO sub 3 (BTO)/SrTiO sub 3 (STO) artificially superstructured thin films. The refinement was achieved by taking into account the effect of interdiffusion between BTO and STO. The samples were prepared by a molecular-beam epitaxy method on SrTiO sub 3 (001) substrate at 600 .deg. C. The phonon model was employed to simulate the X-ray diffraction (XRD) profiles. A discrepancy was observed in the intensities of the satellite peaks when the effect of the interdiffusion between BTO and STO was not incorporated in the simulation. In successive simulations, the concentration profile due to the interdiffusion was first calculated according to Fick's second law, and then the coefficients of the Fourier series describing the lattice distortion and the modulation of the structure factor were determined. The XRD profiles thus simulated almost completely agreed with those observed. This indicates that XRD analysis with the calculation process proposed in this study will ena...

  9. Improving LED CCT uniformity using micropatterned films optimized by combining ray tracing and FDTD methods.

    Science.gov (United States)

    Ding, Xinrui; Li, Jiasheng; Chen, Qiu; Tang, Yong; Li, Zongtao; Yu, Binhai

    2015-02-09

    Although the light-emitting diode (LED) has revolutionized lighting, the non-uniformity of its correlated color temperature (CCT) still remains a major concern. In this context, to improve the light distribution performance of remote phosphor LED lamps, we employ a micropatterned array (MPA) optical film fabricated using a low-cost molding process. The parameters of the MPA, including different installation configurations, positioning, and diameters, are optimized by combining the finite-difference time-domain and ray-tracing methods. Results show that the sample with the upward-facing convex-cone MPA film that has a diameter of half of that of the remote phosphor glass, and is tightly affixed to the inward surface of the remote phosphor glass renders a superior light distribution performance. When compared with the case in which no MPA film is used, the deviation of the CCT distribution decreases from 1033 K to 223 K, and the corresponding output power of the sample is an acceptable level of 85.6%. We perform experiments to verify our simulation results, and the two sets of results exhibit a close agreement. We believe that our approach can be used to optimize MPA films for various lighting applications.

  10. Replicon sizes in mammalian cells as estimated by an x-ray plus bromodeoxyuridine photolysis method

    International Nuclear Information System (INIS)

    Kapp, L.N.; Painter, R.B.

    1978-01-01

    A new method is described for estimating replicon sizes in mammalian cells. Cultures were pulse labeled with [ 3 H]thymidine ([ 3 H]TdR) and bromodeoxyuridine (BrDUrd) for up to 1 h. The lengths of the resulting labeled regions of DNA, L/sub obs/, were estimated by a technique wherein the change in molecular weight of nascent DNA strands, induced by 313 nm light, is measured by velocity sedimentation in alkaline sucrose gradients. If cells are exposed to 1,000 rads of x rays immediately before pulse labeling, initiation of replicon operation is blocked, although chain elongation proceeds almost normally. Under these conditions L/sub obs/ continues to increase only until operating replicons have completed their replication. This value for L/sub obs/ then remains constant as long as the block to initiation remains and represents an estimate for the average size of replicons operating in the cells before x irradiation. For human diploid fibroblasts and human HeLa cells this estimated average size is approximately 17 μM, whereas for Chinese hamster ovary cells, the average replicon size is about 42 μM

  11. Magnetic separation as a method to assist mineralogical characterization of rocks by X-ray diffraction

    International Nuclear Information System (INIS)

    Silva, Amanda Luzia da; Oliveira, Arno Heeren de; Fernandes, Maria Lourdes Souza

    2013-01-01

    The X-ray diffraction (XRD) corresponds to one of the main techniques for characterization of structures in crystalline materials widely used in the identification of minerals in samples of geological materials such as rocks. However, the large number of mineral phases present in a rock sample can generate excess peaks in the diffractogram, and it can promote overlapping peaks and induce erroneous identification. The purpose of this study was to perform magnetic separation of minerals from rock samples in order to enable the identification of the minerals by XRD. For this magnetic separation, two samples of rock were selected: a sample of high silica content and a sample with low silica content. The magnetic separation of minerals from each sample was performed using the magnetic separator isodynamic Frantz. Posteriorly, the fractions obtained in magnetic separations were analyzed by XRD. In the sample with high silica content, it was obtained a fraction where was identified the accessory mineral epidote, which had not been identified in the total sample diffractogram. In the sample with low silica content, the magnetic separation into several mineral fractions made possible to obtain diffraction patterns with fewer peaks and peaks with higher relative intensities, which allowed its mineralogical characterization. The results showed that the mineral separation by the magnetic separator Frantz made the identification of accessory minerals by XRD and the characterization of samples which have many mineral phases possible, which proves that magnetic separation by Frantz is a method which can assist analyses by XRD. (author)

  12. Application of the rigorous method to x-ray and neutron beam scattering on rough surfaces

    International Nuclear Information System (INIS)

    Goray, Leonid I.

    2010-01-01

    The paper presents a comprehensive numerical analysis of x-ray and neutron scattering from finite-conducting rough surfaces which is performed in the frame of the boundary integral equation method in a rigorous formulation for high ratios of characteristic dimension to wavelength. The single integral equation obtained involves boundary integrals of the single and double layer potentials. A more general treatment of the energy conservation law applicable to absorption gratings and rough mirrors is considered. In order to compute the scattering intensity of rough surfaces using the forward electromagnetic solver, Monte Carlo simulation is employed to average the deterministic diffraction grating efficiency due to individual surfaces over an ensemble of realizations. Some rules appropriate for numerical implementation of the theory at small wavelength-to-period ratios are presented. The difference between the rigorous approach and approximations can be clearly seen in specular reflectances of Au mirrors with different roughness parameters at wavelengths where grazing incidence occurs at close to or larger than the critical angle. This difference may give rise to wrong estimates of rms roughness and correlation length if they are obtained by comparing experimental data with calculations. Besides, the rigorous approach permits taking into account any known roughness statistics and allows exact computation of diffuse scattering.

  13. An Efficient Augmented Lagrangian Method for Statistical X-Ray CT Image Reconstruction.

    Science.gov (United States)

    Li, Jiaojiao; Niu, Shanzhou; Huang, Jing; Bian, Zhaoying; Feng, Qianjin; Yu, Gaohang; Liang, Zhengrong; Chen, Wufan; Ma, Jianhua

    2015-01-01

    Statistical iterative reconstruction (SIR) for X-ray computed tomography (CT) under the penalized weighted least-squares criteria can yield significant gains over conventional analytical reconstruction from the noisy measurement. However, due to the nonlinear expression of the objective function, most exiting algorithms related to the SIR unavoidably suffer from heavy computation load and slow convergence rate, especially when an edge-preserving or sparsity-based penalty or regularization is incorporated. In this work, to address abovementioned issues of the general algorithms related to the SIR, we propose an adaptive nonmonotone alternating direction algorithm in the framework of augmented Lagrangian multiplier method, which is termed as "ALM-ANAD". The algorithm effectively combines an alternating direction technique with an adaptive nonmonotone line search to minimize the augmented Lagrangian function at each iteration. To evaluate the present ALM-ANAD algorithm, both qualitative and quantitative studies were conducted by using digital and physical phantoms. Experimental results show that the present ALM-ANAD algorithm can achieve noticeable gains over the classical nonlinear conjugate gradient algorithm and state-of-the-art split Bregman algorithm in terms of noise reduction, contrast-to-noise ratio, convergence rate, and universal quality index metrics.

  14. Magnetic separation as a method to assist mineralogical characterization of rocks by X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Amanda Luzia da; Oliveira, Arno Heeren de; Fernandes, Maria Lourdes Souza, E-mail: amanda@igc.ufmg.br, E-mail: heeren@nuclear.ufmg.br, E-mail: amanda@igc.ufmg.br, E-mail: lurdesfernandes@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horionte, MG (Brazil)

    2013-07-01

    The X-ray diffraction (XRD) corresponds to one of the main techniques for characterization of structures in crystalline materials widely used in the identification of minerals in samples of geological materials such as rocks. However, the large number of mineral phases present in a rock sample can generate excess peaks in the diffractogram, and it can promote overlapping peaks and induce erroneous identification. The purpose of this study was to perform magnetic separation of minerals from rock samples in order to enable the identification of the minerals by XRD. For this magnetic separation, two samples of rock were selected: a sample of high silica content and a sample with low silica content. The magnetic separation of minerals from each sample was performed using the magnetic separator isodynamic Frantz. Posteriorly, the fractions obtained in magnetic separations were analyzed by XRD. In the sample with high silica content, it was obtained a fraction where was identified the accessory mineral epidote, which had not been identified in the total sample diffractogram. In the sample with low silica content, the magnetic separation into several mineral fractions made possible to obtain diffraction patterns with fewer peaks and peaks with higher relative intensities, which allowed its mineralogical characterization. The results showed that the mineral separation by the magnetic separator Frantz made the identification of accessory minerals by XRD and the characterization of samples which have many mineral phases possible, which proves that magnetic separation by Frantz is a method which can assist analyses by XRD. (author)

  15. A coherent/Compton scattering method employing an x-ray tube for measurement of trabecular bone mineral content

    International Nuclear Information System (INIS)

    Puumalainen, P.; Uimarihuhta, A.; Olkkonen, H.

    1982-01-01

    Results showed that the x-ray generator could be used as a radiation source in the coherent/Compton scattering method of measuring trabecular bone mineral content. The quasimonoenergetic x-ray beam was produced from the continuous bremsstrahlung radiation with the aid of a spectral filter. Of the two measuring arrangements that were tested, the semiconductor detector geometry appeared to give distinctly more reproducible results than the two NaI detector system. However, to improve the counting efficiency of the coherent radiation, the 'coherent' NaI detector could be replaced by a bore-through scintillation probe (bore diameter about 10mm). By placing the x-ray fluorescence target inside the bore, the yield would be considerably higher. The present method is suitable for TBMC measurements of small animal and human peripheral bones. Errors are discussed in relation to increase of bone size. (U.K.)

  16. Method comparison of ultrasound and kilovoltage x-ray fiducial marker imaging for prostate radiotherapy targeting

    Science.gov (United States)

    Fuller, Clifton David; Thomas, Charles R., Jr.; Schwartz, Scott; Golden, Nanalei; Ting, Joe; Wong, Adrian; Erdogmus, Deniz; Scarbrough, Todd J.

    2006-10-01

    Several measurement techniques have been developed to address the capability for target volume reduction via target localization in image-guided radiotherapy; among these have been ultrasound (US) and fiducial marker (FM) software-assisted localization. In order to assess interchangeability between methods, US and FM localization were compared using established techniques for determination of agreement between measurement methods when a 'gold-standard' comparator does not exist, after performing both techniques daily on a sequential series of patients. At least 3 days prior to CT simulation, four gold seeds were placed within the prostate. FM software-assisted localization utilized the ExacTrac X-Ray 6D (BrainLab AG, Germany) kVp x-ray image acquisition system to determine prostate position; US prostate targeting was performed on each patient using the SonArray (Varian, Palo Alto, CA). Patients were aligned daily using laser alignment of skin marks. Directional shifts were then calculated by each respective system in the X, Y and Z dimensions before each daily treatment fraction, previous to any treatment or couch adjustment, as well as a composite vector of displacement. Directional shift agreement in each axis was compared using Altman-Bland limits of agreement, Lin's concordance coefficient with Partik's grading schema, and Deming orthogonal bias-weighted correlation methodology. 1019 software-assisted shifts were suggested by US and FM in 39 patients. The 95% limits of agreement in X, Y and Z axes were ±9.4 mm, ±11.3 mm and ±13.4, respectively. Three-dimensionally, measurements agreed within 13.4 mm in 95% of all paired measures. In all axes, concordance was graded as 'poor' or 'unacceptable'. Deming regression detected proportional bias in both directional axes and three-dimensional vectors. Our data suggest substantial differences between US and FM image-guided measures and subsequent suggested directional shifts. Analysis reveals that the vast majority of

  17. Qualitative Evaluation of Digital Hand X-rays is Not a Reliable Method to Assess Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    AndrewJ. Miller

    2017-01-01

    Full Text Available Object: The gold standard for evaluating bone mineral density is dual energy x-ray absorptiometry (DEXA.  Prior studies have shown poor reliability using analog wrist X-rays in diagnosing osteoporosis. Our goal was to investigate if there was improved diagnostic value to visual assessment of digital hand X-rays in osteoporosis screening. We hypothesized that similar to analog counterparts, digital hand X-rays have poor correlation and reliability in determining bone mineral density (BMD relative to DEXA.Methods: We prospectively evaluated female patients older than 65 years who presented to our hand clinic with digital hand and wrist X-rays as part of their evaluation over six months. Patients who had a fracture and were without DEXA scans within the past two years were excluded. Five fellowship-trained hand surgeons, blinded to DEXA T-scores, evaluated the x-rays over two assessments separated by four weeks and classified them as osteoporotic, osteopenic, or normal BMD.  Accuracy relative to DEXA T-score, interobserver and intraobserver rates were calculated.Results: Thirty four patients met the inclusion criteria and a total of 340 x-rays reviews were performed.  The assessments were correct in 169 cases (49% as compared to the DEXA T-scores. A mean weighted kappa coefficient of agreement between observers was 0.29 (range 0.02-0.41 reflecting a fair agreement. The first and second assessment for all five physicians was 0.46 (range 0.19-0.78 reflecting a moderate agreement.  Grouping osteoporosis and osteopenia together compared to normal, the accuracy, interobserver and intraobserver rates increased to 63%, 0.42 and 0.54 respectively.Conclusion: Abnormally low BMD is a common occurrence in patients treated for upper extremity disorders. There is poor accuracy relative to DEXA scan and only fair agreement in diagnosing osteoporosis using visual assessments of digital x-rays.

  18. The integral first collision kernel method for gamma-ray skyshine analysis[Skyshine; Gamma-ray; First collision kernel; Monte Carlo calculation

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, R.-D.; Chui, C.-S.; Jiang, S.-H. E-mail: shjiang@mx.nthu.edu.tw

    2003-12-01

    A simplified method, based on the integral of the first collision kernel, is presented for performing gamma-ray skyshine calculations for the collimated sources. The first collision kernels were calculated in air for a reference air density by use of the EGS4 Monte Carlo code. These kernels can be applied to other air densities by applying density corrections. The integral first collision kernel (IFCK) method has been used to calculate two of the ANSI/ANS skyshine benchmark problems and the results were compared with a number of other commonly used codes. Our results were generally in good agreement with others but only spend a small fraction of the computation time required by the Monte Carlo calculations. The scheme of the IFCK method for dealing with lots of source collimation geometry is also presented in this study.

  19. Resolution improvement and noise reduction in human pinhole SPECT using a multi-ray approach and the SHINE method

    International Nuclear Information System (INIS)

    Seret, A.; Vanhove, C.; Defrise, M.

    2009-01-01

    Purpose: This work aimed at quantifying the gains in spatial resolution and noise that could be achieved when using resolution modelling based on a multi-ray approach and additionally the Statistical and Heuristic Noise Extraction (SHINE) method in human pinhole single photon emission tomography (PH-SPECT). Methods: PH-SPECT of two line phantoms and one homogeneous cylinder were recorded using parameters suited for studies of the human neck area. They were reconstructed using pinhole dedicated ordered subsets expectation maximisation algorithm including a resolution recovery technique based on 7 or 21 rays. Optionally, the SPECT data were SHINE pre-processed. Transverse and axial full widths at half-maximum (FWHM) were obtained from the line phantoms. The noise was quantified using the coefficient of variation (COV) derived from the uniform phantom. Two human PH-SPECT studies of the thyroid (a hot nodule and a very low uptake) were processed with the same algorithms. Results: Depending on the number of iterations, FWHM decreased by 30 to 50% when using the multi-ray approach in the reconstruction process. The SHINE method did not affect the resolution but decreased the COV by at least 20% and by 45% when combined with the multi-ray method. The two human studies illustrated the gain in spatial resolution and the decrease in noise afforded both by the multi-ray reconstruction and the SHINE method. Conclusion: Iterative reconstruction with resolution modelling allows to obtain high resolution human PH-SPECT studies with reduced noise content. The SHINE method affords an additional noise reduction without compromising the resolution. (orig.)

  20. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    Energy Technology Data Exchange (ETDEWEB)

    Mihucz, Victor G. [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); Moricz, Agnes M. [L. Eoetvoes University, Department of Chemical Technology and Environmental Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Kroepfl, Krisztina [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Szikora, Szilvia [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Tatar, Eniko [Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Parra, Lue Meru Marco [Universidad Centro-occidental Lisandro Alvarado, Decanato de Agronomia, Departamento de Quimica y Suelos Unidad de Analisis Instrumental, Apartado Postal 4076, Cabudare 3023 (Venezuela); Zaray, Gyula [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary) and Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary) and L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary)]. E-mail: zaray@ludens.elte.hu

    2006-11-15

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods.

  1. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    International Nuclear Information System (INIS)

    Mihucz, Victor G.; Moricz, Agnes M.; Kroepfl, Krisztina; Szikora, Szilvia; Tatar, Eniko; Parra, Lue Meru Marco; Zaray, Gyula

    2006-01-01

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods

  2. High-resolution X-ray crystal structure of bovine H-protein using the high-pressure cryocooling method

    International Nuclear Information System (INIS)

    Higashiura, Akifumi; Ohta, Kazunori; Masaki, Mika; Sato, Masaru; Inaka, Koji; Tanaka, Hiroaki; Nakagawa, Atsushi

    2013-01-01

    Using the high-pressure cryocooling method, the high-resolution X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. This is the first ultra-high-resolution structure obtained from a high-pressure cryocooled crystal. Recently, many technical improvements in macromolecular X-ray crystallography have increased the number of structures deposited in the Protein Data Bank and improved the resolution limit of protein structures. Almost all high-resolution structures have been determined using a synchrotron radiation source in conjunction with cryocooling techniques, which are required in order to minimize radiation damage. However, optimization of cryoprotectant conditions is a time-consuming and difficult step. To overcome this problem, the high-pressure cryocooling method was developed (Kim et al., 2005 ▶) and successfully applied to many protein-structure analyses. In this report, using the high-pressure cryocooling method, the X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. Structural comparisons between high- and ambient-pressure cryocooled crystals at ultra-high resolution illustrate the versatility of this technique. This is the first ultra-high-resolution X-ray structure obtained using the high-pressure cryocooling method

  3. Fundamental parameters method for quantitative energy dispersive x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Demirel, H.; Zararsiz, A.

    1986-01-01

    In this study, the requirement of the standart material in photon excited energy distributed X-ray fluorescence analysis has been removed. The interaction of X-rays with matter has been taken into account. A computer program has been developed by using the fundamental parameters of X-ray fluorescence technique and the spectral intensity 'K' of pure elements at saturation thickness has been obtained. For experimental purpose a convenient source-target-detector geometry has been designed. In order to excite the samples,Cd-109 radioisotope source has been used. The peak intensities has been obtained in a vacum chamber by counting the emitted X-rays. The calculation of concentration has been performed for double mixed samples correcting the effects of absorption and enchancement factors. The results were in conformity with their certificate values. (author)

  4. Microbeam high-resolution diffraction and x-ray standing wave methods applied to semiconductor structures

    International Nuclear Information System (INIS)

    Kazimirov, A; Bilderback, D H; Huang, R; Sirenko, A; Ougazzaden, A

    2004-01-01

    A new approach to conditioning x-ray microbeams for high angular resolution x-ray diffraction and scattering techniques is introduced. We combined focusing optics (one-bounce imaging capillary) and post-focusing collimating optics (miniature Si(004) channel-cut crystal) to generate an x-ray microbeam with a size of 10 μm and ultimate angular resolution of 14 μrad. The microbeam was used to analyse the strain in sub-micron thick InGaAsP epitaxial layers grown on an InP(100) substrate by the selective area growth technique in narrow openings between the oxide stripes. For the structures for which the diffraction peaks from the substrate and the film overlap, the x-ray standing wave technique was applied for precise measurements of the strain with a Δd/d resolution of better than 10 -4 . (rapid communication)

  5. A novel and simple method for analyzing elements using x-ray induced with femto-second laser

    International Nuclear Information System (INIS)

    Fukushima, M.; Yomogihata, K.; Ono, H.; Hatanaka, K.; Fukumura, H.

    2005-01-01

    It is well known that x-ray emission is induced when materials are irradiated by an intense femto-second laser. Since the x-ray properties of atoms are almost independent of chemical forms or physical states, the induced x-ray emission spectrum is useful for analytical purposes. A new and simple method for analyzing elements in solid and liquid samples has been developed using a femto-second laser with sufficient power to generate x-ray emission. Femto-second pulses from a Ti: sapphire laser system were focused with a microscopic objective lens on samples, and x-ray emission spectra were measured by solid state detector. Though the sensitivity for elements is not so high, this method has several advantages; (1) available to analyze under daylight, (2) available to analyze in the air, (3) no need for the license to radioactive source. Moreover, this laser system can be taken to outside. It means this method can be used for in site analysis. Various kinds of samples were tested; commercial crystal glass, NIST SRM-1633b Coal Fly Ash: GSJ Reference Sample JMn-1 Mn nodule sample, several kinds of geological rocks, law fish slice, and gelatin gel of salt solutions. As a-result, specific x-rays were observed from elements more than l wt% contents in the spectral range of 3-8 keV, For analyzing liquid samples, laser pulses were focused on the surface of water jet stream or filter paper in which solution has soaked. Details of the results will be presented.

  6. A simple method for the deconvolution of 134 Cs/137 Cs peaks in gamma-ray scintillation spectrometry

    International Nuclear Information System (INIS)

    Darko, E.O.; Osae, E.K.; Schandorf, C.

    1998-01-01

    A simple method for the deconvolution of 134 Cs / 137 Cs peaks in a given mixture of 134 Cs and 137 Cs using Nal(TI) gamma-ray scintillation spectrometry is described. In this method the 795 keV energy of 134 Cs is used as a reference peak to calculate the activity of the 137 Cs directly from the measured peaks. Certified reference materials were measured using the method and compared with a high resolution gamma-ray spectrometry measurements. The results showed good agreement with the certified values. The method is very simple and does not need any complicated mathematics and computer programme to de- convolute the overlapping 604.7 keV and 661.6 keV peaks of 134 Cs and 137 Cs respectively. (author). 14 refs.; 1 tab., 2 figs

  7. Comparison of different methods for determining the size of a focal spot of microfocus X-ray tubes

    International Nuclear Information System (INIS)

    Salamon, M.; Hanke, R.; Krueger, P.; Sukowski, F.; Uhlmann, N.; Voland, V.

    2008-01-01

    The EN 12543-5 describes a method for determining the focal spot size of microfocus X-ray tubes up to a minimum spot size of 5 μm. The wide application of X-ray tubes with even smaller focal spot sizes in computed tomography and radioscopy applications requires the evaluation of existing methods for focal spot sizes below 5 μm. In addition, new methods and conditions for determining submicron focal spot sizes have to be developed. For the evaluation and extension of the present methods to smaller focal spot sizes, different procedures in comparison with the existing EN 12543-5 were analyzed and applied, and the results are presented

  8. Spectral Resolution for Five-Element, Filtered, X-Ray Detector (XRD) Arrays Using the Methods of Backus and Gilbert

    International Nuclear Information System (INIS)

    FEHL, DAVID LEE; BIGGS, F.; CHANDLER, GORDON A.; STYGAR, WILLIAM A.

    2000-01-01

    The generalized method of Backus and Gilbert (BG) is described and applied to the inverse problem of obtaining spectra from a 5-channel, filtered array of x-ray detectors (XRD's). This diagnostic is routinely fielded on the Z facility at Sandia National Laboratories to study soft x-ray photons ((le)2300 eV), emitted by high density Z-pinch plasmas. The BG method defines spectral resolution limits on the system of response functions that are in good agreement with the unfold method currently in use. The resolution so defined is independent of the source spectrum. For noise-free, simulated data the BG approximating function is also in reasonable agreement with the source spectrum (150 eV black-body) and the unfold. This function may be used as an initial trial function for iterative methods or a regularization model

  9. Soft structures of γ-ray strength functions studied with the Oslo method

    Directory of Open Access Journals (Sweden)

    Voinov A.

    2010-03-01

    Full Text Available We present experimental γ-ray strength functions up to Eγ ∼ Sn measured at the Oslo Cyclotron Laboratory for several Sc, V, Mo, and Sn isotopes. For the lighter nuclei, an unexpected enhancement of the strength function at low γ-ray energies has been revealed. This enhancement could potentially have an impact on neutron-capture cross sections for unstable, neutron-rich nuclei. For the Sn isotopes, we observe increased strength around the neutron separation energy Sn.

  10. Comparison of the dose surface product in patients with X-ray contrast examinations of the stomach with intermittent and continuous radiographic methods

    International Nuclear Information System (INIS)

    Porzel, C.

    1975-01-01

    After commenting on the proplems of radiation exposure during X-raying and a brief survey of the development of image storage systems, the author explains the pulsed storage system used for X-raying the stomach instead of conventional X-raying. Applying the intermittent X-raying method, the exposure dose could be reduced by 75%, especially in patients with a strong abdominal girth. Advantages and disadvantages and possible ways to use the method for angiography, angiocardiography and X-raying in connection with bone operations are discussed. (ORU) [de

  11. Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses

    International Nuclear Information System (INIS)

    Bionta, M. R.; Hartmann, N.; Weaver, M.; French, D.; Glownia, J. M.; Bostedt, C.; Chollet, M.; Ding, Y.; Fritz, D. M.; Fry, A. R.; Krzywinski, J.; Lemke, H. T.; Messerschmidt, M.; Schorb, S.; Zhu, D.; White, W. E.; Nicholson, D. J.; Cryan, J. P.; Baker, K.; Kane, D. J.

    2014-01-01

    The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10–100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for “measure-and-sort” at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses

  12. Studies of X-ray tube aging by non-invasive methods

    International Nuclear Information System (INIS)

    Bottaro, Marcio.

    2007-01-01

    The objective of the present work was the evaluation of an x ray tube aging with an anode made of tungsten, used in radio diagnostic. Workloads were applied, in accordance with Brazilian workload distribution, and periodic measurements of quantities related to the radiation quality of the beam were performed. For the purpose of this work, a single phase, full bridge clinical system was employed. For the long term x ray tube characteristics evaluation related to the applied workload, it was necessary to measure parameters that could quantitatively represent the tube aging, with special attention to the anode roughening. For the indirect measurement of tube aging, four parameters were chosen, some of them normally applied in x ray diagnostic quality control: first and second half value layers (HVL), focal spot dimensions, non invasive measurement of Practical Peak Voltage (PPV) and x ray spectroscopy. These parameters were measured before any workload and after each workload intervals. To assure confidence of the results reproducibility conditions were stated to each evaluated parameter. The uncertainties involved in all measurement processes were calculated to evaluate the real contributions of x ray tube aging effects on non invasive parameters. Within all evaluated parameters, the most sensitive to long term workload were the mean energy obtained from spectroscopy and half value layers. A model related to these parameters was applied and estimates of x ray tube aging rate for different acceleration voltages and anodic currents were calculated. (author)

  13. Validation of the method of quantitative phase analysis by X-ray diffraction in API: case of Tibolone

    International Nuclear Information System (INIS)

    Silva, R P; Ambrósio, M F S; Epprecht, E K; Avillez, R R; Achete, C A; Kuznetsov, A; Visentin, L C

    2016-01-01

    In this study, different structural and microstructural models applied to X-ray analysis of powder diffraction data of polymorphic mixtures of known concentrations of Tibolone were investigated. The X-ray data obtained in different diffraction instruments were analysed via Rietveld method using the same analytical models. The results of quantitative phase analysis show that regardless of the instrument used, the values of the calculated concentrations follow the same systematics with respect to the final errors. The strategy to select a specific analytical model that leads to lower measurement errors is here presented. (paper)

  14. Determination of solid surface composition by the X-ray fluorescence method under total external reflection with angular scanning

    International Nuclear Information System (INIS)

    Krasnolutskij, V.P.

    2000-01-01

    Possibilities of determination of composition of surface layers by X-ray fluorescence analysis under total reflection of incident radiation with angular scanning of a target are investigated. For the case of the GaAs target it is shown that the sensibility of this method is sufficient for a control of element composition in layer of thickness 1 nm. A simple method for solution of inverse task of analysis of a two component medium is considered [ru

  15. Shielding chalculations in x-rays installations for medical diagnosis. description of the method and computational solution

    International Nuclear Information System (INIS)

    Borroto Valdes, M.; Saez, D.G.

    1992-01-01

    Shielding requirements for x-rays diagnostic installations are investigated. The description of an entirely analytical method for calculation of thickness, based in the papers of Simpkin and NCRP49, is presented. Considerations described in specialized method to solving this problem. A program for microcomputer IBM and compatibles ones is available for estimation of minimum shielding requirements in lead, concrete and steel. Similar results were obtained from comparing with others authors

  16. Recoil Distance Method lifetime measurements via gamma-ray and charged-particle spectroscopy at NSCL

    Science.gov (United States)

    Voss, Philip Jonathan

    The Recoil Distance Method (RDM) is a well-established technique for measuring lifetimes of electromagnetic transitions. Transition matrix elements derived from the lifetimes provide valuable insight into nuclear structure. Recent RDM investigations at NSCL present a powerful new model-independent tool for the spectroscopy of nuclei with extreme proton-to-neutron ratios that exhibit surprising behavior. Neutron-rich 18C is one such example, where a small B(E2; 2+1 → 0+gs) represented a dramatic shift from the expected inverse relationship between the B(E2) and 2+1 excitation energy. To shed light on the nature of this quadrupole excitation, the RDM lifetime technique was applied with the Koln/NSCL plunger. States in 18C were populated by the one-proton knockout reaction of a 19N secondary beam. De-excitation gamma rays were detected with the Segmented Germanium Array in coincidence with reaction residues at the focal plane of the S800 Magnetic Spectrometer. The deduced B(E2) and excitation energy were both well described by ab initio no-core shell model calculations. In addition, a novel extension of RDM lifetime measurements via charged-particle spectroscopy of exotic proton emitters has been investigated. Substituting the reaction residue degrader of the Koln/NSCL plunger with a thin silicon detector permits the study of short-lived nuclei beyond the proton dripline. A proof of concept measurement of the mean lifetime of the two-proton emitter 19Mg was conducted. The results indicated a sub-picosecond lifetime, one order of magnitude smaller than the published results, and validate this new technique for lifetime measurements of charged-particle emitters.

  17. 3D RECONSTRUCTION FROM MULTI-VIEW MEDICAL X-RAY IMAGES – REVIEW AND EVALUATION OF EXISTING METHODS

    Directory of Open Access Journals (Sweden)

    S. Hosseinian

    2015-12-01

    Full Text Available The 3D concept is extremely important in clinical studies of human body. Accurate 3D models of bony structures are currently required in clinical routine for diagnosis, patient follow-up, surgical planning, computer assisted surgery and biomechanical applications. However, 3D conventional medical imaging techniques such as computed tomography (CT scan and magnetic resonance imaging (MRI have serious limitations such as using in non-weight-bearing positions, costs and high radiation dose(for CT. Therefore, 3D reconstruction methods from biplanar X-ray images have been taken into consideration as reliable alternative methods in order to achieve accurate 3D models with low dose radiation in weight-bearing positions. Different methods have been offered for 3D reconstruction from X-ray images using photogrammetry which should be assessed. In this paper, after demonstrating the principles of 3D reconstruction from X-ray images, different existing methods of 3D reconstruction of bony structures from radiographs are classified and evaluated with various metrics and their advantages and disadvantages are mentioned. Finally, a comparison has been done on the presented methods with respect to several metrics such as accuracy, reconstruction time and their applications. With regards to the research, each method has several advantages and disadvantages which should be considered for a specific application.

  18. Application of focused-beam flat-sample method to synchrotron powder X-ray diffraction with anomalous scattering effect

    International Nuclear Information System (INIS)

    Tanaka, M; Katsuya, Y; Matsushita, Y

    2013-01-01

    The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe 2 O 4 and Fe 3 O 4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe 2+ /Fe 3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.

  19. Chromatic X-ray magnifying method and apparatus by Bragg reflective planes on the surface of Abbe sphere

    Science.gov (United States)

    Thoe, Robert S.

    1991-01-01

    Method and apparatus for producing sharp, chromatic, magnified images of X-ray emitting objects, are provided. The apparatus, which constitutes an X-ray microscope or telescope, comprises a connected collection of Bragg reflecting planes, comprised of either a bent crystal or a synthetic multilayer structure, disposed on and adjacent to a locus determined by a spherical surface. The individual Bragg planes are spatially oriented to Bragg reflect radiation from the object location toward the image location. This is accomplished by making the Bragg planes spatially coincident with the surfaces of either a nested series of prolate ellipsoids of revolution, or a nested series of spheres. The spacing between the Bragg reflecting planes can be tailored to control the wavelengths and the amount of the X-radiation that is Bragg reflected to form the X-ray image.

  20. Background estimation in short-wave region during determination of total sample composition by x-ray fluorescence method

    International Nuclear Information System (INIS)

    Simakov, V.A.; Kordyukov, S.V.; Petrov, E.N.

    1988-01-01

    Method of background estimation in short-wave spectral region during determination of total sample composition by X-ray fluorescence method is described. 13 types of different rocks with considerable variations of base composition and Zr, Nb, Th, U content below 7x10 -3 % are investigated. The suggested method of background accounting provides for a less statistical error of the background estimation than direct isolated measurement and reliability of its determination in a short-wave region independent on the sample base. Possibilities of suggested method for artificial mixtures conforming by the content of main component to technological concemtrates - niobium, zirconium, tantalum are estimated

  1. X-ray spectrum analysis of multi-component samples by a method of fundamental parameters using empirical ratios

    International Nuclear Information System (INIS)

    Karmanov, V.I.

    1986-01-01

    A type of the fundamental parameter method based on empirical relation of corrections for absorption and additional-excitation with absorbing characteristics of samples is suggested. The method is used for X-ray fluorescence analysis of multi-component samples of charges of welded electrodes. It is shown that application of the method is justified only for determination of titanium, calcium and silicon content in charges taking into account only corrections for absorption. Irn and manganese content can be calculated by the simple method of the external standard

  2. A New Method to Constrain Supernova Fractions Using X-ray Observations of Clusters of Galaxies

    Science.gov (United States)

    Bulbul, Esra; Smith, Randall K.; Loewenstein, Michael

    2012-01-01

    Supernova (SN) explosions enrich the intracluster medium (ICM) both by creating and dispersing metals. We introduce a method to measure the number of SNe and relative contribution of Type Ia supernovae (SNe Ia) and core-collapse supernovae (SNe cc) by directly fitting X-ray spectral observations. The method has been implemented as an XSPEC model called snapec. snapec utilizes a single-temperature thermal plasma code (apec) to model the spectral emission based on metal abundances calculated using the latest SN yields from SN Ia and SN cc explosion models. This approach provides a self-consistent single set of uncertainties on the total number of SN explosions and relative fraction of SN types in the ICM over the cluster lifetime by directly allowing these parameters to be determined by SN yields provided by simulations. We apply our approach to XMM-Newton European Photon Imaging Camera (EPIC), Reflection Grating Spectrometer (RGS), and 200 ks simulated Astro-H observations of a cooling flow cluster, A3112.We find that various sets of SN yields present in the literature produce an acceptable fit to the EPIC and RGS spectra of A3112. We infer that 30.3% plus or minus 5.4% to 37.1% plus or minus 7.1% of the total SN explosions are SNe Ia, and the total number of SN explosions required to create the observed metals is in the range of (1.06 plus or minus 0.34) x 10(exp 9), to (1.28 plus or minus 0.43) x 10(exp 9), fromsnapec fits to RGS spectra. These values may be compared to the enrichment expected based on well-established empirically measured SN rates per star formed. The proportions of SNe Ia and SNe cc inferred to have enriched the ICM in the inner 52 kiloparsecs of A3112 is consistent with these specific rates, if one applies a correction for the metals locked up in stars. At the same time, the inferred level of SN enrichment corresponds to a star-to-gas mass ratio that is several times greater than the 10% estimated globally for clusters in the A3112 mass range.

  3. Method of separation of celestial gamma-ray bursts from solar flares

    International Nuclear Information System (INIS)

    Chuang, K.W.; White, R.S.; Klebesadel, R.W.; Laros, J.G.

    1991-01-01

    We recently discovered 217 ''new'' celestial gamma-ray burst candidates from the ''new'' burst search of the PVO real time data base. 1 The burst search covered the time period from September 1978 to July 1988. Sixty were confirmed by at lest on other spacecraft, e.g., ISEE-3, V-11, V-12, etc. None triggered the PVO high time resolution memory. In this paper we describe a new algorithm based ont eh relationship between time width T w and hardness ratio HR, to distinguish cosmic gamma-ray bursts from solar flares without knowing the directions of the events. The criteria for identification as a gamma-ray burst candidate are: If T ww ≤a then HR≥bT w , or T w >a then HR>c. Otherwise, the event is a solar flare candidate. Here, a, b, and c are parameter which differ for different gamma-ray burst detectors. For PVO, a=18.8 s, b=(1.38/18.8) s -1 , and c=1.38. This algorithm was tested with 83 triggered and 60 nontriggered confirmed gamma-ray burst and 30 confirmed solar flares from PVO

  4. Spalling stress in oxidized thermal barrier coatings evaluated by X-ray diffraction method

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K. [Faculty of Education and Human Sciences, Niigata Univ., Niigata (Japan); Tanaka, K. [Dept. of Mechanical Engineering, Nagoya Univ., Furoh-cho, Chikusa-ku, Nagoya (Japan)

    2005-07-01

    The spallation of thermal barrier coatings (TBCs) is promoted by thermally grown oxide (TGO). To improve TBCs, it is very important to understand the influence of TGO on the spalling stress. In this study 'the TBCs were oxidized at 1373 K for four different periods: 0, 500,1000 and 2000 h. The distribution of the in-plane stress in oxidized TBCs, {sigma}{sub 1}, was obtained by repeating the X-ray stress measurement with low energy X-rays after successive removal of the surface layer. The distribution of the out-of-plane stress, {sigma}{sub 1} - {sigma}{sub 3}, was measured with hard synchrotron X-rays, because high energy X-rays have a large penetration depth. From the results by the low and high energy X-rays, the spalling stress in the oxidized TBCs, {sigma}{sub 3}, was evaluated. The evaluated value of the spalling stress for the oxidized TBC was a small tension beneath the surface, but steeply increased near the interface between the top and bond coating. This large tensile stress near the interface is responsible for the spalling of the top coating. (orig.)

  5. Use of x-ray radiographic methods in the study of clay liners

    International Nuclear Information System (INIS)

    Malone, P.G.; May, J.H.; Brown, K.W.; Thomas, J.C.

    1986-01-01

    X-ray radiography has been widely used in soil investigation to study the distribution of layers in soil cores and the effects of changing conditions (loading or impact) on soil structure. X-ray radiographic techniques also can be useful in studying clays or clay soils used in liners. Laboratory investigations were undertaken to demonstrate that X-ray radiographic techniques could be used to detect density and soil structure changes that usually accompany variations in hydraulic conductivity of clay liners. An example of a real-time test of a simulated bentonite and sand, liner attacked with acid lead nitrate and examples of radiographic examination of clay soil (non-calcareous smectite) samples that have been permeated by lead acetate or lead nitrate are presented. The changes in density and structure can be related to changes observed in hydraulic conductivity during permeation. X-ray radiography easily can be applied to field samples of soil or clay liner materials to detect density and structural changes that occur as the liner and permeating fluid interact. X-ray techniques have applications in both understanding failure mechanisms and forecasting liner performance

  6. A method for visual inspection of welding by means of image processing of x-ray photograph

    International Nuclear Information System (INIS)

    Koshimizu, Hiroyasu; Yoshida, Tohru.

    1983-01-01

    Computer image processing is becoming a helpful tool even in industrial inspections. A computerized method for welding visual inspection is proposed in this paper. This method is based on computer image processing of X-ray photograph of welding, in which the appearance information of weldments such as shape of weld bead really exists. Structural patterns are extracted at first and seven computer measures for inspection are calculated using those patterns. Software system for visual inspection is constructed based on these seven measures. It was experimentally made clear that this system can provide a performance of more than 0.85 correlation to human visual inspection. As a result, the visual inspection by computer using X-ray photograph became a promising tool to realize objectivity and quantitativity of welding inspection. Additionally, the consistency of the system, the possibility to reduce computing costs, and so on are discussed to improve the proposed method. (author)

  7. The relative-intensity method of X-ray fluorescence analysis and its application to soils and rocks

    International Nuclear Information System (INIS)

    Childs, C.W.; Furkert, R.J.

    1974-01-01

    The relative-intensity X-ray fluorescence method of analysis of rock and soil samples has been investigated and compared with the net-intensity method. Strong, coherently scattered radiation originating from the X-ray tube is shown to be preferable to background radiation as an internal standard, and scattered radiation measured at one wavelength can usefully be applied in the determination of several elements. When the concentrations of an element in two soil samples of different composition (for example concretions and the soil adjacent to them) are compared, the ratio of the relative intensities may be different from the ratio of net intensities by a factor of about two. The concentrations of manganese in thirteen standard rock samples determined by the relative-intensity method are within or very close to the ranges of values reported previously

  8. Evaluation of physical property of light-weight soil with air foam using X-ray CT method

    International Nuclear Information System (INIS)

    Otani, Jun; Mukunoki, Toshifumi; Kikuchi, Yoshiaki

    2000-01-01

    The objective of this paper is to investigate the physical property of light-weight soil made of dredged slurry mixed with air foam and cement using X-ray CT method. In this study, not only the specimen made in laboratory but also the one sampled at the in-situ construction site were used and the property in the soil was visualized and the distributions of the density an air porosity were evaluated quantitatively using the results of CT scanning. Here, the method of image processing analysis was also used for this evaluation study. Based on the results obtained in this study, it is concluded that the X-ray CT method is a powerful tool even for geotechnical engineering and this makes not only the visualization but also the quantitative ion discussion possible for the light-weight soil with air foam. (author)

  9. Proximal gamma-ray spectroscopy to predict soil properties using windows and full-spectrum analysis methods.

    Science.gov (United States)

    Mahmood, Hafiz Sultan; Hoogmoed, Willem B; van Henten, Eldert J

    2013-11-27

    Fine-scale spatial information on soil properties is needed to successfully implement precision agriculture. Proximal gamma-ray spectroscopy has recently emerged as a promising tool to collect fine-scale soil information. The objective of this study was to evaluate a proximal gamma-ray spectrometer to predict several soil properties using energy-windows and full-spectrum analysis methods in two differently managed sandy loam fields: conventional and organic. In the conventional field, both methods predicted clay, pH and total nitrogen with a good accuracy (R2 ≥ 0.56) in the top 0-15 cm soil depth, whereas in the organic field, only clay content was predicted with such accuracy. The highest prediction accuracy was found for total nitrogen (R2 = 0.75) in the conventional field in the energy-windows method. Predictions were better in the top 0-15 cm soil depths than in the 15-30 cm soil depths for individual and combined fields. This implies that gamma-ray spectroscopy can generally benefit soil characterisation for annual crops where the condition of the seedbed is important. Small differences in soil structure (conventional vs. organic) cannot be determined. As for the methodology, we conclude that the energy-windows method can establish relations between radionuclide data and soil properties as accurate as the full-spectrum analysis method.

  10. Study of imperfect natural diamonds with the application of the X-ray synchrotron radiation (the 'Laue-SR' method)

    International Nuclear Information System (INIS)

    Rylov, G.M.; Yefimova, E.S.; Sobolev, N.V.; Kulipanov, G.N.; Kondratyev, V.I.; Tolochko, B.P.; Sharafutdinov, M.R.

    2001-01-01

    The 'Laue-SR' method has been realised for fast gathering experimental data in the study of imperfect natural and synthesised diamonds which are hard to investigate with the conventional X-ray methods. Time to obtain a diffraction pattern with the use of the polychromatic SR is shorter by several orders; the resolution of the image of substructure defects of a crystal lattice (as compared to the conventional Laue method) is improved by an order and does not vanish even at large disorientation or other non-coherent disturbances of the crystal lattice. The 'Laue-SR' method is especially appropriate for the study of intact, sufficiently large diamond crystals (up to 5 mm), since the diamond has a small coefficient of the X-ray absorption and is practically transparent in the operational range of the SR waves, λ=0.5-1.5 A. This method was shown to be applied successfully for an accelerated study of a large bulk of imperfect natural diamond crystals without any preliminary preparation and without their destruction, which enlarges the information output in the study and, besides that, increases significantly the efficiency of the work. X-ray 'Laue-SR' topograms of imperfect diamonds with different types of distortions of the crystal lattice by natural processes during the formation of the diamonds and by epigenetic impacts are shown

  11. Determination of iron and titanium in kaolins by the method of non-dispersive X-ray fluorescence

    International Nuclear Information System (INIS)

    Bialy, N.; Kierzek, J.; Parus, J.

    1976-01-01

    The possibility of application of the radioactive source excited X-ray fluorescence analysis for titanium and iron determination in kaolins to the routine test of the refinement process has been studied. The iron content can be determined with a simple counting system using a single-channel pulse height analyser, argon filled proportional counter and 109 Cd source of 3 mCi for the excitation of K Fe rays. The samples were analyzed both as pellets and powders. The iron content ranged from 0.2-2.5% and titanium from 0.1-0.64%. The best values of precision and determination limit have been achieved for iron with 238 Pu and for titanium with 55 Fe. The precision and accuracy of the X-ray fluorescence method of iron and titanium determination in kaolins are comparable to those of the chemical method. For the simultaneous iron and titanium determination in the discussed region of concentration it is the most advantageous to use the plutonium source with the activity of several tens of mCi and Si(Li) detector with a moderate resolution (250-300 eV for 5.9 keV). The time of the analysis carried out by the described method is several times shorter than the chemical method. The apparatus used in this method is relatively simple, the sample preparation does not require any chemical treatment and the cost of labour of the sample preparation is minimal. (T.G.)

  12. Acquiring molecular interference functions of X-ray coherent scattering for breast tissues by combination of simulation and experimental methods

    International Nuclear Information System (INIS)

    Chaparian, A.; Oghabian, M. A.; Changizi, V.

    2009-01-01

    Recently, it has been indicated that X-ray coherent scatter from biological tissues can be used to access signature of tissue. Some scientists are interested in studying this effect to get early detection of breast cancer. Since experimental methods for optimization are time consuming and expensive, some scientists suggest using simulation. Monte Carlo codes are the best option for radiation simulation: however, one permanent defect with Monte Carlo codes has been the lack of a sufficient physical model for coherent (Rayleigh) scattering, including molecular interference effects. Materials and Methods: It was decided to obtain molecular interference functions of coherent X-ray scattering for normal breast tissues by combination of modeling and experimental methods. A Monte Carlo simulation program was written to simulate the angular distribution of scattered photons for the normal breast tissue samples. Moreover, experimental diffraction patterns of these tissues were measured by means of energy dispersive X-ray diffraction method. The simulation and experimental data were used to obtain a tabulation of molecular interference functions for breast tissues. Results: With this study a tabulation of molecular interference functions for normal breast tissues Was prepared to facilitate the simulation diffraction patterns of the tissues without any experimental. Conclusion: The method may lead to design new systems for early detection of breast cancer.

  13. Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

    International Nuclear Information System (INIS)

    Warburton, W.K.; Hubbard, B.

    1999-01-01

    A signal processing system which accepts input from an x-ray detector-preamplifier and produces a signal of reduced dynamic range for subsequent analog-to-digital conversion is disclosed. The system conditions the input signal to reduce the number of bits required in the analog-to-digital converter by removing that part of the input signal which varies only slowly in time and retaining the amplitude of the pulses which carry information about the x-rays absorbed by the detector. The parameters controlling the signal conditioner's operation can be readily supplied in digital form, allowing it to be integrated into a feedback loop as part of a larger digital x-ray spectroscopy system. 13 figs

  14. Comparisons between digital gamma-ray spectrometer (DSPec) and standard nuclear instrumentation methods (NIM) systems

    International Nuclear Information System (INIS)

    Vo, D.T.; Russo, P.A.; Sampson, T.E.

    1998-03-01

    Safeguards isotopic measurements require the best spectrometer systems with excellent resolution, stability and throughput. Up until about a year ago, gamma ray spectroscopy has always been done using the analog amplifier, which processes the pulses from the preamplifier to remove the noise, reject the pile up signals, and shape the signals into some desirable form before sending them to the analog to digital converter (ADC) to be digitized. In late 1996, EG and G Ortec introduced a digital gamma ray spectrometer (DSPec) which uses digital technology to analyze the preamplifiers' pulses from all types of germanium and silicon detectors. Considering its performance, digital based spectroscopy may become the way of future gamma ray spectroscopy

  15. Dosage of silicon in a soluble silicate using an x-ray-fluorescence radioisotopic method

    International Nuclear Information System (INIS)

    Wasilewska, M.; Robert, A.

    1969-01-01

    A description is given of a spectrometer for X ray fluorescence analysis having a radio active excitation source. It has been applied to the analysis of the silicon contained in an industrial soluble silicate. A theoretical study has been made for this analysis of the operational conditions such as: the effect of the particle size, the dilution of the sample, the sensitivity as a function of the X ray excitation energy. It is possible to obtain a relative accuracy of 0,87 per cent for the silicon determination, for one standard deviation. A comparison is made of the sensitivity obtained using this apparatus for the Si determination with that which can be obtained using a conventional apparatus fitted with an X ray tube. (author) [fr

  16. Novel x-ray imaging methods at the Nova Laser Facility

    International Nuclear Information System (INIS)

    Ress, D.; DaSilva, L.B.; London, R.A.; Trebes, J.E.; Lerche, R.A.; Bradley, D.K.

    1994-01-01

    We are pursuing several novel x-ray imaging schemes to measure plasma parameters in inertial-confinement fusion experiments. This paper will review two quite successful approaches, the soft x-ray moire deflectometer, and the annular (ring) coded-aperture microscope. The deflectometer is the newer diagnostic, and this paper will concentrate on this topic. We will describe the operating principles of moire deflectometry, give the motivations for soft x-ray probing, describe the physical apparatus in detail, and present some sample images and results. The ring coded-aperture microscope has been described previously, so here we will only briefly review the principle of the instrument. We will concentrate on the signal-to-noise ratio calculations that motivate the use of annular coded apertures, and describe recent work to predict and measure the resolution of the instrument

  17. X- or gamma ray converter and manufacturing method for its cathode system

    International Nuclear Information System (INIS)

    Baeuerlein, R.; Uhl, D.; Diepers, H.; Jablonski, K.H.

    1981-01-01

    The X-ray converter serves for application in medical diagnostics. For the cathode system of the converter a system based on low-pressure ionography is suited making use of the X-ray photoelectric emission. The electrodes of the cathode system consist of double-layer films with two external conduction layers and an insulator in between. As an auxiliary voltage can be applied between the individual layers the field gradient in the holes may be adjusted, thus increasing the quantum yield. (orig./HP)

  18. A simple, semi-quantitative method for measuring pulsed soft x-rays

    International Nuclear Information System (INIS)

    Takahama, Y.; Du, J.; Yanagidaira, T.; Hirano, K.

    1993-01-01

    A simple semi-quantitative measurement and image processing system for pulsed soft X-rays with a time and spatial resolution is proposed. Performance of the system is examined using a cylindrical soft X-ray source generated with a plasma device. The system consists of commercial facilities which are easily obtained such as a microchannel plate-phosphor screen combination, a CCD camera, an image memory board and a personal computer. To make a quantitative measurement possible, the image processing and observation of the phosphor screen current are used in conjunction. (author)

  19. Development of multielement neutron-capture prompt γ-rays activation analysis method

    International Nuclear Information System (INIS)

    Liu Yuren; Xie Yali; Zhao Yunzhi; Liu Jiping; Meng Bonian

    1998-01-01

    The relationship between content of the measured elements and area of typical peaks of prompt γ-rays is presented. The root-mean square errors on both the regression value of instrumentation analysis and chemical analysis for some common elements are lower than 0.5wt%. Function of the slowing body was found and analysis sensitivity was enhanced obviously in the iron ore analysis. The FWHM of the spectrometer for the H prompt γ-ray peak (2.223 MeV) is 3 keV

  20. X- or gamma ray converter and manufacturing method for its cathode system

    Energy Technology Data Exchange (ETDEWEB)

    Baeuerlein, R; Uhl, D; Diepers, H; Jablonski, K H

    1981-02-05

    The X-ray converter serves for application in medical diagnostics. For the cathode system of the converter a system based on low-pressure ionography is suited making use of the X-ray photoelectric emission. The electrodes of the cathode system consist of double-layer films with two external conduction layers and an insulator in between. As an auxiliary voltage can be applied between the individual layers the field gradient in the holes may be adjusted, thus increasing the quantum yield.

  1. Improving accuracy and capabilities of X-ray fluorescence method using intensity ratios

    Energy Technology Data Exchange (ETDEWEB)

    Garmay, Andrey V., E-mail: andrew-garmay@yandex.ru; Oskolok, Kirill V.

    2017-04-15

    An X-ray fluorescence analysis algorithm is proposed which is based on a use of ratios of X-ray fluorescence lines intensities. Such an analytical signal is more stable and leads to improved accuracy. Novel calibration equations are proposed which are suitable for analysis in a broad range of matrix compositions. To apply the algorithm to analysis of samples containing significant amount of undetectable elements a use of a dependence of a Rayleigh-to-Compton intensity ratio on a total content of these elements is suggested. The technique's validity is shown by analysis of standard steel samples, model metal oxides mixture and iron ore samples.

  2. Methods for studying the focal spot size and resolution of diagnostic X-ray tubes

    International Nuclear Information System (INIS)

    Fairbanks, R.; Doust, C.

    1979-01-01

    Attention is given to techniques appropriate for use in the clinical situation. The focal spot size is critical to geometric unsharpness and hence the quality of the finished radiograph, but pinhole imaging of the focal spot is extremely difficult in clinical practice. The resolution of an X-ray tube, although a function of focal spot size, is of more importance in radiography. A comparison is made of various resolution grids suitable for quality control use in X-ray departments. (U.K.)

  3. The cosmological analysis of X-ray cluster surveys - I. A new method for interpreting number counts

    Science.gov (United States)

    Clerc, N.; Pierre, M.; Pacaud, F.; Sadibekova, T.

    2012-07-01

    We present a new method aimed at simplifying the cosmological analysis of X-ray cluster surveys. It is based on purely instrumental observable quantities considered in a two-dimensional X-ray colour-magnitude diagram (hardness ratio versus count rate). The basic principle is that even in rather shallow surveys, substantial information on cluster redshift and temperature is present in the raw X-ray data and can be statistically extracted; in parallel, such diagrams can be readily predicted from an ab initio cosmological modelling. We illustrate the methodology for the case of a 100-deg2XMM survey having a sensitivity of ˜10-14 erg s-1 cm-2 and fit at the same time, the survey selection function, the cluster evolutionary scaling relations and the cosmology; our sole assumption - driven by the limited size of the sample considered in the case study - is that the local cluster scaling relations are known. We devote special attention to the realistic modelling of the count-rate measurement uncertainties and evaluate the potential of the method via a Fisher analysis. In the absence of individual cluster redshifts, the count rate and hardness ratio (CR-HR) method appears to be much more efficient than the traditional approach based on cluster counts (i.e. dn/dz, requiring redshifts). In the case where redshifts are available, our method performs similar to the traditional mass function (dn/dM/dz) for the purely cosmological parameters, but constrains better parameters defining the cluster scaling relations and their evolution. A further practical advantage of the CR-HR method is its simplicity: this fully top-down approach totally bypasses the tedious steps consisting in deriving cluster masses from X-ray temperature measurements.

  4. Determination of preferential molecular orientation in porphyrin-fullerene dyad ZnDHD6ee monolayers by the X-ray standing-wave method and X-ray reflectometry

    NARCIS (Netherlands)

    Seregin, A. Y.; D' Yakova, Y. A.; Yakunin, S. N.; Makhotkin, I. A.; Alekseev, A. S.; Klechkovskaya, V. V.; Tereschenko, E. Y.; Tkachenko, N. V.; Lemmetyinen, H.; Feigin, L. A.; Kovalchuk, M. V.

    2013-01-01

    Monolayers of porphyrin-fullerene dyad molecules with zinc atoms incorporated into the porphyrin ring (ZnDHD6ee) on the surface of aqueous subphase and on Si substrates have been investigated by the X-ray standing-wave method and X-ray reflectometry. The experiments have been performed under

  5. Simple Method to Estimate Mean Heart Dose From Hodgkin Lymphoma Radiation Therapy According to Simulation X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Nimwegen, Frederika A. van [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Cutter, David J. [Clinical Trial Service Unit, University of Oxford, Oxford (United Kingdom); Oxford Cancer Centre, Oxford University Hospitals NHS Trust, Oxford (United Kingdom); Schaapveld, Michael [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Rutten, Annemarieke [Department of Radiology, The Netherlands Cancer Institute, Amsterdam (Netherlands); Kooijman, Karen [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Krol, Augustinus D.G. [Department of Radiation Oncology, Leiden University Medical Center, Leiden (Netherlands); Janus, Cécile P.M. [Department of Radiation Oncology, Erasmus MC Cancer Center, Rotterdam (Netherlands); Darby, Sarah C. [Clinical Trial Service Unit, University of Oxford, Oxford (United Kingdom); Leeuwen, Flora E. van [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Aleman, Berthe M.P., E-mail: b.aleman@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam (Netherlands)

    2015-05-01

    Purpose: To describe a new method to estimate the mean heart dose for Hodgkin lymphoma patients treated several decades ago, using delineation of the heart on radiation therapy simulation X-rays. Mean heart dose is an important predictor for late cardiovascular complications after Hodgkin lymphoma (HL) treatment. For patients treated before the era of computed tomography (CT)-based radiotherapy planning, retrospective estimation of radiation dose to the heart can be labor intensive. Methods and Materials: Patients for whom cardiac radiation doses had previously been estimated by reconstruction of individual treatments on representative CT data sets were selected at random from a case–control study of 5-year Hodgkin lymphoma survivors (n=289). For 42 patients, cardiac contours were outlined on each patient's simulation X-ray by 4 different raters, and the mean heart dose was estimated as the percentage of the cardiac contour within the radiation field multiplied by the prescribed mediastinal dose and divided by a correction factor obtained by comparison with individual CT-based dosimetry. Results: According to the simulation X-ray method, the medians of the mean heart doses obtained from the cardiac contours outlined by the 4 raters were 30 Gy, 30 Gy, 31 Gy, and 31 Gy, respectively, following prescribed mediastinal doses of 25-42 Gy. The absolute-agreement intraclass correlation coefficient was 0.93 (95% confidence interval 0.85-0.97), indicating excellent agreement. Mean heart dose was 30.4 Gy with the simulation X-ray method, versus 30.2 Gy with the representative CT-based dosimetry, and the between-method absolute-agreement intraclass correlation coefficient was 0.87 (95% confidence interval 0.80-0.95), indicating good agreement between the two methods. Conclusion: Estimating mean heart dose from radiation therapy simulation X-rays is reproducible and fast, takes individual anatomy into account, and yields results comparable to the labor

  6. Computer simulation tools for X-ray analysis scattering and diffraction methods

    CERN Document Server

    Morelhão, Sérgio Luiz

    2016-01-01

    The main goal of this book is to break down the huge barrier of difficulties faced by beginners from many fields (Engineering, Physics, Chemistry, Biology, Medicine, Material Science, etc.) in using X-rays as an analytical tool in their research. Besides fundamental concepts, MatLab routines are provided, showing how to test and implement the concepts. The major difficult in analyzing materials by X-ray techniques is that it strongly depends on simulation software. This book teaches the users on how to construct a library of routines to simulate scattering and diffraction by almost any kind of samples. It provides to a young student the knowledge that would take more than 20 years to acquire by working on X-rays and relying on the available textbooks. In this book, fundamental concepts in applied X-ray physics are demonstrated through available computer simulation tools. Using MatLab, more than eighty routines are developed for solving the proposed exercises, most of which can be directly used in experimental...

  7. [Particle size determination by radioisotope x-ray absorptiometry with sedimentation method].

    Science.gov (United States)

    Matsui, Y; Furuta, T; Miyagawa, S

    1976-09-01

    The possibility of radioisotope X-ray absorptiometry to determine the particle size of powder in conjunction with sedimentation was investigated. The experimental accuracy was primarily determined by Cow and X-ray intensity. where Co'=weight concentration of the particle in the suspension w'=(micron/rho)l/(mu/rho)s-rhol/rhos rho; density micron/rho; mass absorption coefficient, suffix l and s indicate dispersion and particle, respectively. The radiosiotopes, Fe-55, Pu-238 and Cd-109 have high w-values over the wide range of the atomic number. However, a source of high micron value such as Fe-55 is not suitable because the optimal X-ray transmission length, Lopt is decided by the expression, micronlLopt approximately 2/(1+C'ow') by using Cd-109 AgKX-ray source, the weight size distribution of particles from the heavy elements such as PbO2 to light elements such as Al2O3 or flyash was determined.

  8. Some method of treating experimental data from X-ray chamber experiments

    International Nuclear Information System (INIS)

    Michalak, W.; Sroka, J.

    1977-01-01

    The procedure of studying the scaling law conservation using the cosmic radiation data from emulsion chambers is presented. The gamma-ray families are selected and processed in order to investigate the cascade development dependency on the primary particle energy. The most meaningful gamma family characteristics are proposed. (S.B.)

  9. 3D Laser Imprint Using a Smoother Ray-Traced Power Deposition Method

    Science.gov (United States)

    Schmitt, Andrew J.

    2017-10-01

    Imprinting of laser nonuniformities in directly-driven icf targets is a challenging problem to accurately simulate with large radiation-hydro codes. One of the most challenging aspects is the proper construction of the complex and rapidly changing laser interference structure driving the imprint using the reduced laser propagation models (usually ray-tracing) found in these codes. We have upgraded the modelling capability in our massively-parallel fastrad3d code by adding a more realistic EM-wave interference structure. This interference model adds an axial laser speckle to the previous transverse-only laser structure, and can be impressed on our improved smoothed 3D raytrace package. This latter package, which connects rays to form bundles and performs power deposition calculations on the bundles, is intended to decrease ray-trace noise (which can mask or add to imprint) while using fewer rays. We apply this improved model to 3D simulations of recent imprint experiments performed on the Omega-EP laser and the Nike laser that examined the reduction of imprinting due to very thin high-Z target coatings. We report on the conditions in which this new model makes a significant impact on the development of laser imprint. Supported by US DoE/NNSA.

  10. Study on the identification method of chemical warfare agents with spectroscopy of neutron induced γ rays

    International Nuclear Information System (INIS)

    Liu Boxue; Li Yun; Li Xiangbao

    1996-01-01

    The paper briefly describes some non-destructive verification technologies of chemical warfare agents in-site, and some application of neutron induced gamma ray analysis, such as multi-elements analysis of coal, hidden explosive detection and identification of chemical agents. It also describes some problems in developing the portable isotopic neutron spectroscopy for non-destructive evaluation of chemical warfare agents

  11. Depression cathode structure for cathode ray tubes having surface smoothness and method for producing same

    International Nuclear Information System (INIS)

    Rychlewski, T.V.

    1984-01-01

    Depression cathode structures for cathode ray tubes are produced by dispensing liquid cathode material into the depression of a metallic supporting substrate, removing excess cathode material by passing a doctor blade across the substrate surface and over the depression, and drying the cathode layer to a substantially immobile state. The cathode layer may optionally be further shaped prior to substantially complete drying thereof

  12. X-ray examination of the stomach - a highly informative noninvasive examination method

    Energy Technology Data Exchange (ETDEWEB)

    Grehn, S.

    1987-10-01

    The X-ray examination of the stomach still holds its own in this age of sophisticated endoscopic examination techniques. Nevertheless, it needs to be based on a meticulous examination technique performed by the physian in person on the patient and resulting in convincing imaging. (orig.)

  13. Evaluation of high packing density powder X-ray screens by Monte Carlo methods

    International Nuclear Information System (INIS)

    Liaparinos, P.; Kandarakis, I.; Cavouras, D.; Kalivas, N.; Delis, H.; Panayiotakis, G.

    2007-01-01

    Phosphor materials are employed in intensifying screens of both digital and conventional X-ray imaging detectors. High packing density powder screens have been developed (e.g. screens in ceramic form) exhibiting high-resolution and light emission properties, and thus contributing to improved image transfer characteristics and higher radiation to light conversion efficiency. For the present study, a custom Monte Carlo simulation program was used in order to examine the performance of ceramic powder screens, under various radiographic conditions. The model was developed using Mie scattering theory for the description of light interactions, based on the physical characteristics (e.g. complex refractive index, light wavelength) of the phosphor material. Monte Carlo simulations were carried out assuming: (a) X-ray photon energy ranging from 18 up to 49 keV, (b) Gd 2 O 2 S:Tb phosphor material with packing density of 70% and grain size of 7 μm and (c) phosphor thickness ranging between 30 and 70 mg/cm 2 . The variation of the Modulation Transfer Function (MTF) and the Luminescence Efficiency (LE) with respect to the X-ray energy and the phosphor thickness was evaluated. Both aforementioned imaging characteristics were shown to take high values at 49 keV X-ray energy and 70 mg/cm 2 phosphor thickness. It was found that high packing density screens may be appropriate for use in medical radiographic systems

  14. Contribution to the element analysis method by proton-induced X-ray spectroscopy

    International Nuclear Information System (INIS)

    Montenegro, E.C.

    1977-02-01

    A critical analysis of the process for the mass determination using proton induced X-ray is presented. Problems such as univocity, reproducibility, precision, accuracy and sensibility, as well as possible effects of absorption in the sample are considered. (author) [pt

  15. Methods for improvement of some parameters of medical X-ray diagnostic equipment. Basic faults in selection of appropriate new or used units

    International Nuclear Information System (INIS)

    Tonev, M.; Danev, N.; Constantinov, B.

    2004-01-01

    An analysis is made of the factors determining the quality and performance of the main types of medical equipment: conventional radiographic and fluoroscopic X-ray unit; X-ray computer tomograph (CT); angiographic, mammographic, densitometric and dental X-ray equipment; magnetic resonance MRI. The aim is to give certain directions for the method one should adopt on choosing and purchasing X-ray equipment. Also one should take into consideration the new Health law and the Regulation for radiation protection of persons undergoing medical examination or treatment. The problems can be solved with the close cooperation between radiologists, medical physicists and x-ray engineers

  16. Introducing a standard method for experimental determination of the solvent response in laser pump, x-ray probe time-resolved wide-angle x-ray scattering experiments on systems in solution

    DEFF Research Database (Denmark)

    Kjær, Kasper Skov; Brandt van Driel, Tim; Kehres, Jan

    2013-01-01

    In time-resolved laser pump, X-ray probe wide-angle X-ray scattering experiments on systems in solution the structural response of the system is accompanied by a solvent response. The solvent response is caused by reorganization of the bulk solvent following the laser pump event, and in order...... response-the solvent term-experimentally when applying laser pump, X-ray probe time-resolved wide-angle X-ray scattering. The solvent term describes difference scattering arising from the structural response of the solvent to changes in the hydrodynamic parameters: pressure, temperature and density. We...... is demonstrated to exhibit first order behaviour with respect to the amount of energy deposited in the solution. We introduce a standardized method for recording solvent responses in laser pump, X-ray probe time-resolved X-ray wide-angle scattering experiments by using dye mediated solvent heating. Furthermore...

  17. X-ray Tomography and Impregnation Methods to Analyze Pore Space Hetrerogeneities at the Hydrated State

    International Nuclear Information System (INIS)

    Pret, D.; Ferrage, E.; Tertre, E.; Robinet, J.C.; Faurel, M.; Hubert, F.; Pelletier, M.; Bihannic, I.

    2013-01-01

    environmental conditions and preparations are used. In case of methods able to deal with wet atmospheres and nanometre resolution, sub-sampling millimetre or micrometre size hydrated samples without inducing shearing or fractures is also not still proven. Optimization of impregnation procedure for water saturated clay samples still plays a pivotal role for applying the most advanced imaging techniques at the nanometre scale. In addition, natural clay rocks in sedimentary basins or engineered barriers in deep repositories could not swell or shrink by changing their macroscopic volume. Such case corresponds to constrained swelling conditions that implies a distribution of pore and water highly contrasting with dry state and hydrated state in free swelling conditions. Moreover, swelling rate could potentially be limited down to the crystal scale. As probing in-situ the organization of hydrated and compacted clay materials into an odometer set-up is challenging, it is really poorly documented in literature. Note that opening an odometer setup and analyzing a sample is not a constrained swelling condition: immediate swelling and change of pore space occurs. Natural clayey rocks in sedimentary basins display additional spatial variations of mineral and porosity distributions with contrasted spatial frequencies or gradual evolutions due to sedimentation cycles, temporal evolutions of climate, variations of sources, diagenesis, etc. At the scale of a laboratory sample, geological history still imposes a heterogeneous spatial distribution of mineral and pore space down-scaling to the crystal scale. Localizing samples with a millimetre size or less against the heterogeneities encountered at larger scale is thus important before analyzing it with a nanometre resolution. The best is to follow a continuous down-scaling approach all along the characterization of the organization, keeping the sample in a similar state between each technique. Here we propose a method to fully impregnate up to

  18. On stream radioisotope X-ray fluorescence analyser and a method for the determination of copper in slurry

    International Nuclear Information System (INIS)

    Holynska, B.; Lankosz, M.; Lacki, E.; Ostachowicz, J.; Baran, W.; Owsiak, T.

    1975-01-01

    The paper presents an ''on stream'' analyser and a radioisotope X-ray fluorescence method for the continuous determination of copper content in feed 0.5-2.5% Cu, concentrates 15-25% Cu and tailings 0.01-0.03% Cu. The analyser consists essentially of a radioisotope X-ray fluorescence measuring head, γ-density gauge, electronic unit, analog processor and recorders. The method is based on the measurement of the characteristic radiation of Cu series, selected by nickel-cobalt filters. The total relative error (1s) of the determination of copper in feed is 6-8%, in concentrates 5-7% and in tailings about 18%. The ''on stream'' analyser has been succesfully operated in a pilot plant. (author)

  19. Qualitative Analysis of Chang'e-1 γ-ray Spectrometer Spectra Using Noise Adjusted Singular Value Decomposition Method

    International Nuclear Information System (INIS)

    Yang Jia; Ge Liangquan; Xiong Shengqing

    2010-01-01

    From the features of spectra shape of Chang'e-1 γ-ray spectrometer(CE1-GRS) data, it is difficult to determine elemental compositions on the lunar surface. Aimed at this problem, this paper proposes using noise adjusted singular value decomposition (NASVD) method to extract orthogonal spectral components from CE1-GRS data. Then the peak signals in the spectra of lower-order layers corresponding to the observed spectrum of each lunar region are respectively analyzed. Elemental compositions of each lunar region can be determined based upon whether the energy corresponding to each peak signal equals to the energy corresponding to the characteristic gamma-ray line emissions of specific elements. The result shows that a number of elements such as U, Th, K, Fe, Ti, Si, O, Al, Mg, Ca and Na are qualitatively determined by this method. (authors)

  20. A method for unfolding high-energy scintillation gamma-ray spectra up to 8 MeV

    International Nuclear Information System (INIS)

    Dymke, N.; Hofmann, B.

    1982-01-01

    In unfolding a high-energy scintillation gamma-ray spectrum up to 8 MeV with the help of a response matrix, the means of linear algebra fail if the matrix is ill conditioned. In such cases, unfolding could be accomplished by means of a mathematical method based on a priori knowledge of the photon spectrum to be expected. The method which belongs to the class of regularization techniques was tested on in-situ gamma-ray spectra of 16 N recorded in a nuclear power plant near the primary circuit, using an 1.5 x 1.5 in. NaI(Tl) scintillation detector. For one regularized unfolding the results were presented in the form of an energy and a dose-rate spectrum. (author)

  1. Simple method to estimate mean heart dose from Hodgkin lymphoma radiation therapy according to simulation X-rays.

    Science.gov (United States)

    van Nimwegen, Frederika A; Cutter, David J; Schaapveld, Michael; Rutten, Annemarieke; Kooijman, Karen; Krol, Augustinus D G; Janus, Cécile P M; Darby, Sarah C; van Leeuwen, Flora E; Aleman, Berthe M P

    2015-05-01

    To describe a new method to estimate the mean heart dose for Hodgkin lymphoma patients treated several decades ago, using delineation of the heart on radiation therapy simulation X-rays. Mean heart dose is an important predictor for late cardiovascular complications after Hodgkin lymphoma (HL) treatment. For patients treated before the era of computed tomography (CT)-based radiotherapy planning, retrospective estimation of radiation dose to the heart can be labor intensive. Patients for whom cardiac radiation doses had previously been estimated by reconstruction of individual treatments on representative CT data sets were selected at random from a case-control study of 5-year Hodgkin lymphoma survivors (n=289). For 42 patients, cardiac contours were outlined on each patient's simulation X-ray by 4 different raters, and the mean heart dose was estimated as the percentage of the cardiac contour within the radiation field multiplied by the prescribed mediastinal dose and divided by a correction factor obtained by comparison with individual CT-based dosimetry. According to the simulation X-ray method, the medians of the mean heart doses obtained from the cardiac contours outlined by the 4 raters were 30 Gy, 30 Gy, 31 Gy, and 31 Gy, respectively, following prescribed mediastinal doses of 25-42 Gy. The absolute-agreement intraclass correlation coefficient was 0.93 (95% confidence interval 0.85-0.97), indicating excellent agreement. Mean heart dose was 30.4 Gy with the simulation X-ray method, versus 30.2 Gy with the representative CT-based dosimetry, and the between-method absolute-agreement intraclass correlation coefficient was 0.87 (95% confidence interval 0.80-0.95), indicating good agreement between the two methods. Estimating mean heart dose from radiation therapy simulation X-rays is reproducible and fast, takes individual anatomy into account, and yields results comparable to the labor-intensive representative CT-based method. This simpler method may produce a

  2. Effects of different premature chromosome condensation method on dose-curve of 60Co γ-ray

    International Nuclear Information System (INIS)

    Guo Yicao; Yang Haoxian; Yang Yuhua; Li Xi'na; Huang Weixu; Zheng Qiaoling

    2012-01-01

    Objective: To study the effect of traditional method and improved method of the premature chromosome condensation (PCC) on the dose-effect curve of 60 Co γ ray, for choosing the rapid and accurate biological dose estimating method for the accident emergency. Methods: Collected 3 healthy male cubits venous blood (23 to 28 years old), and irradiated by 0, 1.0, 5.0, 10.0, 15.0, 20.0 Gy 60 Co γ ray (absorbed dose rate: 0.635 Gy/min). Observed the relation of dose-effect curve in the 2 incubation time (50 hours and 60 hours) of the traditional method and improved method. Used the dose-effect curve to verify the exposure of 10.0 Gy (absorbed dose rate: 0.670 Gy/min). Results: (1) In the traditional method of 50-hour culture, the PCC cell count in 15.0 Gy and 20.0 Gy was of no statistical significance. But there were statistical significance in the traditional method of 60-hours culture and improved method (50-hour culture and 60-hour culture). Used the last 3 culture methods to make dose curve. (2) In the above 3 culture methods, the related coefficient between PCC ring and exposure dose was quite close (all of more than 0.996, P 0.05), the morphology of regression straight lines almost overlap. (3) Used the above 3 dose-effect curves to estimate the irradiation results (10.0 Gy), the error was less than or equal to 8%, all of them were within the allowable range of the biological experiment (15%). Conclusion: The 3 dose-effect curves of the above 3 culture methods can apply to biological dose estimating of large doses of ionizing radiation damage. Especially the improved method of 50-hour culture,it is much faster to estimate and it should be regarded as the first choice in accident emergency. (authors)

  3. Operation method of the X-ray equipment for the investigation of the ballooning of LWR-fuel rod simulators

    International Nuclear Information System (INIS)

    Mueller, S.; Thun, G.

    1977-06-01

    An X-Ray-equipment is described which has been selected and assembled for the recording of fuel rod simulator-deformations during a loss of coolant accident using a movie technique. With this method it is possible to observe and record the ballooning of the simulator under conditions similar to those in a reactor. Some typical pictures are shown which show that the quality is high enough to allow a quantitative evaluation of the ballooning as a function of time. (orig.) [de

  4. Determination of the Modulation Transfer Function of Screen-Film Combinations in X-ray photography by the grating method

    International Nuclear Information System (INIS)

    Hoeschen, D.

    1987-01-01

    An intercomparison experiment concerning the determination of the Modulation Transfer Function (MTF) of Screen-Film Combinations in x-ray photography by the grating method was made. Six laboratories located in four countries participated. Each laboratory has used its own, individually developed measurement procedure. The results have shown a surprisingly good agreement, the standard deviation (1 σ value) of MTF values reported by the different laboratories was about ± 0.02

  5. The Determination of Composite Elements in Zircaloy-2 by X-Ray Fluorescence and Emission Spectrometry Method

    International Nuclear Information System (INIS)

    Dian Anggraini; Rosika Kriswarini; Yusuf N

    2007-01-01

    Analysis of composing elements in zircaloy-2 has been done by Emission Spectrometry method and X-Ray Fluorescence (XRF). The aim of the analysis is to verify conformity between composing elements in zircaloy-2 and the material certificate. Spectrometry Emission method has higher sensitivity in element determination of a material than that of XRF method, so can be estimated that emission spectrometry method has higher accuracy than that of XRF method. The result of qualitative analysis by Emission Spectrometry indicate that the composing elements in zircaloy-2 were Sn, Cr and Ni. However, the qualitative analysis result by XRF method indicated that the composing elements in zircaloy 2 were Sn, Cr, Ni and Fe. Fe element can not be analysed by Emission Spectrometry method because Emission Spectrometer did not equipped with Fe detector. The quantitative analysis result of the composing elements in the material with both methods showed that Sn, Cr and Ni concentration of zircaloy 2 existed in concentration ranges of the material certificate. Result of statistical test (F and t-test) of analysis result of both methods can be used for analyzing composing elements in zircaloy 2. Emission Spectrometry method was more sensitive and accurate for determining Cr and Ni element in zircaloy 2 than that of emission Spectrometry method but both methods had same accuracy. The precision of measurement of Sn, Cr and Ni element using XRF method was better than that of Emission spectrometry method. (author)

  6. The development of a postal method to assess X-ray beam parameters and image quality in dental radiology

    International Nuclear Information System (INIS)

    Fenton, D.M.

    1994-10-01

    Intraoral radiographs are an extremely valuable diagnostic tool in dentistry. Radiography permits the early detection and diagnosis of dental disease and consequently is used extensively. However, public concern about radiation exposure has increased in recent times. This concern is reflected in national and international law, to the extent that, the basic principles of radiological protection, that is, justification, optimisation and dose limitation are written into law. Furthermore, in Ireland, the regulations, as outlined in the Code of Practice for Radiological Protection in Dentistry, require intraoral dental X-ray machines to perform to certain standards. A report of a direct survey of 164 intraoral dental X-ray machines is given in this study. The survey covered mechanical, electrical as well as radiation safety. Inadequacies with respect to focus to skin distance and timer accuracy were found in 45% and 42% of the machines surveyed. Ninety eight machines were assessed for electrical safety in which 48% were found to be unsafe. The results indicate that a complete assessment of the performance of dental X-ray units in Ireland is required. However, as there are in excess of 800 dental X-ray machines located throughout the country, such an assessment would be very costly for the regulatory authority. The development of a postal method for the assessment of the performance of dental X-ray machines is described in this study. This postal method provides information on the kV, total filtration, beam width and timer linearity and is undertaken by means of a penetrameter and film envelopes for exposure to the X-ray set under examination, together with a questionnaire that requests information on environment in which the machine is located. Using this method an accuracy of +-5% of the actual value was achieved in the measurement of kVp. The penetrameter was also used to assess whether or not the filtration of a particular machine complies with the regulations. This

  7. X-Ray Diffraction (XRD) Characterization Methods for Sigma=3 Twin Defects in Cubic Semiconductor (100) Wafers

    Science.gov (United States)

    Park, Yeonjoon (Inventor); Kim, Hyun Jung (Inventor); Skuza, Jonathan R. (Inventor); Lee, Kunik (Inventor); King, Glen C. (Inventor); Choi, Sang Hyouk (Inventor)

    2017-01-01

    An X-ray defraction (XRD) characterization method for sigma=3 twin defects in cubic semiconductor (100) wafers includes a concentration measurement method and a wafer mapping method for any cubic tetrahedral semiconductor wafers including GaAs (100) wafers and Si (100) wafers. The methods use the cubic semiconductor's (004) pole figure in order to detect sigma=3/{111} twin defects. The XRD methods are applicable to any (100) wafers of tetrahedral cubic semiconductors in the diamond structure (Si, Ge, C) and cubic zinc-blend structure (InP, InGaAs, CdTe, ZnSe, and so on) with various growth methods such as Liquid Encapsulated Czochralski (LEC) growth, Molecular Beam Epitaxy (MBE), Organometallic Vapor Phase Epitaxy (OMVPE), Czochralski growth and Metal Organic Chemical Vapor Deposition (MOCVD) growth.

  8. A statistical method for retrospective cardiac and respiratory motion gating of interventional cardiac x-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Panayiotou, Maria, E-mail: maria.panayiotou@kcl.ac.uk; King, Andrew P.; Housden, R. James; Ma, YingLiang; Rhode, Kawal S. [Division of Imaging Sciences and Biomedical Engineering, King' s College London, London SE1 7EH (United Kingdom); Cooklin, Michael; O' Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo [Department of Cardiology, Guy' s and St. Thomas' Hospitals NHS Foundation Trust, London SE1 7EH (United Kingdom)

    2014-07-15

    Purpose: Image-guided cardiac interventions involve the use of fluoroscopic images to guide the insertion and movement of interventional devices. Cardiorespiratory gating can be useful for 3D reconstruction from multiple x-ray views and for reducing misalignments between 3D anatomical models overlaid onto fluoroscopy. Methods: The authors propose a novel and potentially clinically useful retrospective cardiorespiratory gating technique. The principal component analysis (PCA) statistical method is used in combination with other image processing operations to make our proposed masked-PCA technique suitable for cardiorespiratory gating. Unlike many previously proposed techniques, our technique is robust to varying image-content, thus it does not require specific catheters or any other optically opaque structures to be visible. Therefore, it works without any knowledge of catheter geometry. The authors demonstrate the application of our technique for the purposes of retrospective cardiorespiratory gating of normal and very low dose x-ray fluoroscopy images. Results: For normal dose x-ray images, the algorithm was validated using 28 clinical electrophysiology x-ray fluoroscopy sequences (2168 frames), from patients who underwent radiofrequency ablation (RFA) procedures for the treatment of atrial fibrillation and cardiac resynchronization therapy procedures for heart failure. The authors established end-systole, end-expiration, and end-inspiration success rates of 97.0%, 97.9%, and 97.0%, respectively. For very low dose applications, the technique was tested on ten x-ray sequences from the RFA procedures with added noise at signal to noise ratio (SNR) values of√(5)0, √(1)0, √(8), √(6), √(5), √(2), and √(1) to simulate the image quality of increasingly lower dose x-ray images. Even at the low SNR value of √(2), representing a dose reduction of more than 25 times, gating success rates of 89.1%, 88.8%, and 86.8% were established. Conclusions: The proposed

  9. First test of the prompt gamma ray timing method with heterogeneous targets at a clinical proton therapy facility

    International Nuclear Information System (INIS)

    Hueso-González, Fernando; Enghardt, Wolfgang; Golnik, Christian; Petzoldt, Johannes; Pausch, Guntram; Fiedler, Fine; Priegnitz, Marlen; Römer, Katja E; Wagner, Andreas; Janssens, Guillaume; Prieels, Damien; Smeets, Julien; Vander Stappen, François

    2015-01-01

    Ion beam therapy promises enhanced tumour coverage compared to conventional radiotherapy, but particle range uncertainties significantly blunt the achievable precision. Experimental tools for range verification in real-time are not yet available in clinical routine. The prompt gamma ray timing method has been recently proposed as an alternative to collimated imaging systems. The detection times of prompt gamma rays encode essential information about the depth-dose profile thanks to the measurable transit time of ions through matter. In a collaboration between OncoRay, Helmholtz-Zentrum Dresden-Rossendorf and IBA, the first test at a clinical proton accelerator (Westdeutsches Protonentherapiezentrum Essen, Germany) with several detectors and phantoms is performed. The robustness of the method against background and stability of the beam bunch time profile is explored, and the bunch time spread is characterized for different proton energies. For a beam spot with a hundred million protons and a single detector, range differences of 5 mm in defined heterogeneous targets are identified by numerical comparison of the spectrum shape. For higher statistics, range shifts down to 2 mm are detectable. A proton bunch monitor, higher detector throughput and quantitative range retrieval are the upcoming steps towards a clinically applicable prototype. In conclusion, the experimental results highlight the prospects of this straightforward verification method at a clinical pencil beam and settle this novel approach as a promising alternative in the field of in vivo dosimetry. (paper)

  10. High-resolution X-ray crystal structure of bovine H-protein using the high-pressure cryocooling method.

    Science.gov (United States)

    Higashiura, Akifumi; Ohta, Kazunori; Masaki, Mika; Sato, Masaru; Inaka, Koji; Tanaka, Hiroaki; Nakagawa, Atsushi

    2013-11-01

    Recently, many technical improvements in macromolecular X-ray crystallography have increased the number of structures deposited in the Protein Data Bank and improved the resolution limit of protein structures. Almost all high-resolution structures have been determined using a synchrotron radiation source in conjunction with cryocooling techniques, which are required in order to minimize radiation damage. However, optimization of cryoprotectant conditions is a time-consuming and difficult step. To overcome this problem, the high-pressure cryocooling method was developed (Kim et al., 2005) and successfully applied to many protein-structure analyses. In this report, using the high-pressure cryocooling method, the X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. Structural comparisons between high- and ambient-pressure cryocooled crystals at ultra-high resolution illustrate the versatility of this technique. This is the first ultra-high-resolution X-ray structure obtained using the high-pressure cryocooling method.

  11. Mössbauer, magnetization and X-ray diffraction characterization methods for iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gabbasov, Raul, E-mail: gabbasov-raul@yandex.ru [National Research Center “Kurchatov Institute”, Moscow (Russian Federation); Polikarpov, Michael; Cherepanov, Valery [National Research Center “Kurchatov Institute”, Moscow (Russian Federation); Chuev, Michael; Mischenko, Iliya; Lomov, Andrey [Institute of Physics and Technology, Russian Academy of Sciences, Moscow (Russian Federation); Wang, Andrew [Ocean NanoTech. Springdale, AR (United States); Panchenko, Vladislav [National Research Center “Kurchatov Institute”, Moscow (Russian Federation)

    2015-04-15

    Water soluble magnetite iron oxide nanoparticles with oleic polymer coating and average diameters in the range of 5–25 nm, previously determined by TEM, were characterized using Mössbauer, magnetization and X-ray diffraction measurements. Comparative analysis of the results demonstrated a large diversity of magnetic relaxation regimes. Analysis showed the presence of an additional impurity component in the 25 nm nanoparticles, with principally different magnetic nature at the magnetite core. In some cases, X-ray diffraction measurements were unable to estimate the size of the magnetic core and Mössbauer data were necessary for the correct interpretation of the experimental results. - Highlights: • KV parameter, obtained from Mössbauer spectra can be used for nanoparticle size characterization. • Mössbauer spectra of 10–25 nm nanoparticles can be effectively described by ferromagnetic model. • Surface impurities can cause incorrect nanoparticle size determination.

  12. Method and apparatus for digitally based high speed x-ray spectrometer

    International Nuclear Information System (INIS)

    Warburton, W.K.; Hubbard, B.

    1997-01-01

    A high speed, digitally based, signal processing system which accepts input data from a detector-preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system achieves high throughputs at low cost by dividing the required digital processing steps between a ''hardwired'' processor implemented in combinatorial digital logic, which detects the presence of the x-ray signals in the digitized data stream and extracts filtered estimates of their amplitudes, and a programmable digital signal processing computer, which refines the filtered amplitude estimates and bins them to produce the desired spectral analysis. One set of algorithms allow this hybrid system to match the resolution of analog systems while operating at much higher data rates. A second set of algorithms implemented in the processor allow the system to be self calibrating as well. The same processor also handles the interface to an external control computer. 19 figs

  13. An iterative method for unfolding time-resolved soft x-ray spectra of laser plasmas

    International Nuclear Information System (INIS)

    Tang Yongjian; Shen Kexi; Xu Hepin

    1991-01-01

    Dante-recorded temporal waveforms have been unfolded by using Fast Fourier transformation (FFT) and the inverted convolution theorem of Fourier analysis. The conversion of the signals to time-dependent soft x-ray spectra is accomplished on the IBM-PC/XT-286 microcomputer system with the code DTSP including SAND II reported by W.N.Mcelory et al.. An amplitude-limited iterative and periodic smoothing technique has been developed in the code DTSP. Time-resolved soft x-ray spectra with sixteen time-cell, and time-dependent radiation, [T R (t)], have been obtained for hohlraum targets irradiated with laser beams (λ = 1.06 μm) on LF-12 in 1989

  14. Computational Methods for Nanoscale X-ray Computed Tomography Image Analysis of Fuel Cell and Battery Materials

    Science.gov (United States)

    Kumar, Arjun S.

    Over the last fifteen years, there has been a rapid growth in the use of high resolution X-ray computed tomography (HRXCT) imaging in material science applications. We use it at nanoscale resolutions up to 50 nm (nano-CT) for key research problems in large scale operation of polymer electrolyte membrane fuel cells (PEMFC) and lithium-ion (Li-ion) batteries in automotive applications. PEMFC are clean energy sources that electrochemically react with hydrogen gas to produce water and electricity. To reduce their costs, capturing their electrode nanostructure has become significant in modeling and optimizing their performance. For Li-ion batteries, a key challenge in increasing their scope for the automotive industry is Li metal dendrite growth. Li dendrites are structures of lithium with 100 nm features of interest that can grow chaotically within a battery and eventually lead to a short-circuit. HRXCT imaging is an effective diagnostics tool for such applications as it is a non-destructive method of capturing the 3D internal X-ray absorption coefficient of materials from a large series of 2D X-ray projections. Despite a recent push to use HRXCT for quantitative information on material samples, there is a relative dearth of computational tools in nano-CT image processing and analysis. Hence, we focus on developing computational methods for nano-CT image analysis of fuel cell and battery materials as required by the limitations in material samples and the imaging environment. The first problem we address is the segmentation of nano-CT Zernike phase contrast images. Nano-CT instruments are equipped with Zernike phase contrast optics to distinguish materials with a low difference in X-ray absorption coefficient by phase shifting the X-ray wave that is not diffracted by the sample. However, it creates image artifacts that hinder the use of traditional image segmentation techniques. To restore such images, we setup an inverse problem by modeling the X-ray phase contrast

  15. Criteria to stablish an absolute semiquantitative analytic method by x-ray fluorescence

    International Nuclear Information System (INIS)

    Echeverria, Fernando.

    1990-01-01

    This work had been developed by fluorescence x-ray laboratory of Nuclear Studies Centre form Ecuador, it pretent to stablish an appropiate discernement of a FRX spectrum to know the concentration range form sample elements, minerals principaly, submit to a FRX. The study tries to stablish the best way to calibration the instruments like the adecuate samples preparation to do the analysis by FRX

  16. Study of distribution of electron density in heteropolymolybdates by method of X-ray electron spectroscopy

    International Nuclear Information System (INIS)

    Molchanov, V.N.; Kazanskij, L.P.; Torchenkova, E.A.; Spitsyn, V.I.

    1978-01-01

    X-ray electron spectra of some iso- and heteropolymolybdates relating to different structure types are investigated to study electron structure of complex polyoxyion-heteropolyanions. Binding energies of Modsub(5/2) and 01s-electrons in iso- and heteropolycompounds line are measured and their interdependence is detected. The effective charge of oxygen and molybdenum atoms in heteropolymolybdates increases with decreasing a number of external sphere cations per an oxygen atom and a number of Mo=0 multiple bonds

  17. New methods of X-ray study of the rectum and colon in patients with constipation

    International Nuclear Information System (INIS)

    Zarodnyuk, I.V.; Tikhonov, A.A.; Sinyaeva, L.M.

    1998-01-01

    Rectal and colonic X-ray findings of 100 patients with constipation are presented. Modified irrigoscopic procedure using barium enema was used. This made it possible not only to determine the shape, dimensions, and position of the rectum and colon, but to reveal a number of anatomic and functional changes in the rectum and pelvic floor, which was helpful in choosing a treatment policy for patients with colonic evacuator dysfunction

  18. In-Situ Synchrotron X-ray Study of the Phase and Texture Evolution of Ceria and Superconductor Films Deposited by Chemical Solution Method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; He, Dong

    2012-01-01

    In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry/differential ther......In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry...

  19. A self-sufficient and general method for self-absorption correction in gamma-ray spectrometry using GEANT4

    International Nuclear Information System (INIS)

    Hurtado, S.; Villa, M.; Manjon, G.; Garcia-Tenorio, R.

    2007-01-01

    This paper presents a self-sufficient and general method for measurement of the activity of low-level gamma-emitters in voluminous samples by gamma-ray spectrometry with a coaxial germanium detector. Due to self-absorption within the sample, the full-energy peak efficiency of low-energy emitters in semiconductor gamma-spectrometers depends strongly on a number of factors including sample composition, density, sample size and gamma-ray energy. As long as those commented factors are well characterized, the influence of self-absorption in the full-energy peak efficiency of low-energy emitters can be calculated using Monte Carlo method based on GEANT4 code for each individual sample. However this task is quite tedious and time consuming. In this paper, we propose an alternative method to determine this influence for voluminous samples of unknown composition. Our method combines both transmission measurements and Monte Carlo simulations, avoiding the application of Monte Carlo full-energy peak efficiency determinations for each individual sample. To test the accuracy and precision of the proposed method, we have calculated 210 Pb activity in sediments samples from an estuary located in the vicinity of several phosphates factories with the proposed method, comparing the obtained results with the ones determined in the same samples using two alternative radiometric techniques

  20. A new method for x-ray fluorescence analysis of contaminated material. Final Report

    International Nuclear Information System (INIS)

    Grodzins, Lee; Niland, John

    2002-01-01

    Niton has successfully completed the objectives of the Phase II program to build a hand-held, x-ray fluorescent analyzer optimized for DOE decontamination and decommissioning activities in the field. A two-pound x-ray fluorescence analyzer was developed that contains 3 radioactive sources, emitting 3 widely spaced monochromatic x-rays, to give the lowest detection limits for the full range of toxic elements, from chromium to plutonium. A rapid, fundamental- parameters algorithm was developed that yields quantitative results in less than 1 second. High-resolution silicon drift detectors and silicon PIN diodes give excellent efficiency and speed. These results from Phase II have been introduced into the XL 300, 700 and 800 commercial products series. More than 800 of these instruments, yielding revenues of more than $20 million dollars, have been sold since the first 3-source instrument was introduced in 1998. A direct consequence of the Phase II funding has been the growth of Niton from 20 people to its present size of 60

  1. A new method for x-ray fluorescence analysis of contaminated material. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Grodzins, Lee; Niland, John

    2002-05-23

    Niton has successfully completed the objectives of the Phase II program to build a hand-held, x-ray fluorescent analyzer optimized for DOE decontamination and decommissioning activities in the field. A two-pound x-ray fluorescence analyzer was developed that contains 3 radioactive sources, emitting 3 widely spaced monochromatic x-rays, to give the lowest detection limits for the full range of toxic elements, from chromium to plutonium. A rapid, fundamental- parameters algorithm was developed that yields quantitative results in less than 1 second. High-resolution silicon drift detectors and silicon PIN diodes give excellent efficiency and speed. These results from Phase II have been introduced into the XL 300, 700 and 800 commercial products series. More than 800 of these instruments, yielding revenues of more than $20 million dollars, have been sold since the first 3-source instrument was introduced in 1998. A direct consequence of the Phase II funding has been the growth of Niton from 20 people to its present size of 60.

  2. Resolution of a protein sequence ambiguity by X-ray crystallographic and mass spectrometric methods

    International Nuclear Information System (INIS)

    Keefe, L.J.; Lattman, E.E.; Wolkow, C.; Woods, A.; Chevrier, M.; Cotter, R.J.

    1992-01-01

    Ambiguities in amino acid sequences are a potential problem in X-ray crystallographic studies of proteins. Amino acid side chains often cannot be reliably identified from the electron density. Many protein crystal structures that are now being solved are simple variants of a known wild-type structure. Thus, cloning artifacts or other untoward events can readily lead to cases in which the proposed sequence is not correct. An example is presented showing that mass spectrometry provides an excellent tool for analyzing suspected errors. The X-ray crystal structure of an insertion mutant of Staphylococcal nuclease has been solved to 1.67 A resolution and refined to a crystallographic R value of 0.170. A single residue has been inserted in the C-terminal α helix. The inserted amino acid was believed to be an alanine residue, but the final electron density maps strongly indicated that a glycine had been inserted instead. To confirm the observations from the X-ray data, matrix-assisted laser desorption mass spectrometry was employed to verify the glycine insertion. This mass spectrometric technique has sufficient mass accuracy to detect the methyl group that distinguishes glycine from alanine and can be extended to the more common situation in which crystallographic measurements suggest a problem with the sequence, but cannot pinpoint its location or nature. (orig.)

  3. Resolution of a protein sequence ambiguity by X-ray crystallographic and mass spectrometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Keefe, L.J.; Lattman, E.E. (Dept. of Biophysics and Biophysical Chemistry, Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)); Wolkow, C.; Woods, A.; Chevrier, M.; Cotter, R.J. (Middle Atlantic Mass Spectrometry Lab., Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States))

    1992-04-01

    Ambiguities in amino acid sequences are a potential problem in X-ray crystallographic studies of proteins. Amino acid side chains often cannot be reliably identified from the electron density. Many protein crystal structures that are now being solved are simple variants of a known wild-type structure. Thus, cloning artifacts or other untoward events can readily lead to cases in which the proposed sequence is not correct. An example is presented showing that mass spectrometry provides an excellent tool for analyzing suspected errors. The X-ray crystal structure of an insertion mutant of Staphylococcal nuclease has been solved to 1.67 A resolution and refined to a crystallographic R value of 0.170. A single residue has been inserted in the C-terminal {alpha} helix. The inserted amino acid was believed to be an alanine residue, but the final electron density maps strongly indicated that a glycine had been inserted instead. To confirm the observations from the X-ray data, matrix-assisted laser desorption mass spectrometry was employed to verify the glycine insertion. This mass spectrometric technique has sufficient mass accuracy to detect the methyl group that distinguishes glycine from alanine and can be extended to the more common situation in which crystallographic measurements suggest a problem with the sequence, but cannot pinpoint its location or nature. (orig.).

  4. Device for monitoring X-ray radiation and method of using same

    International Nuclear Information System (INIS)

    Schaffer, D. L.

    1985-01-01

    Each of a plurality of thermoluminescent detectors (TLD's) is secured to one of a plurality of slides, which are removably mounted in a like plurality of pockets formed in a generally wallet-sized carrier to open on one edge thereof. One additional TLD is secured in a recess in one corner of the carrier to be exposed to all X-ray radiation which falls upon the carrier. Each slide is releasably secured in its associated pocket by means which prevents accidental removal of the side from the pocket. Whenever the owner of the carrier is subjected to an X-ray examination, he or she removes from the carrier one of the slides having thereon an unused TLD, and by a means of adhesive on the back of the slide adheres the associated TLD directly in the path of the X-ray radiation to which the patient is subjected during the examination. After the examination the slide is returned to its pocket in the carrier. Periodically the used TLD elements, as well as the non-removable TLD element, can be processed in a conventional manner to determine the total amount of radiation recorded by the respective elements. In one embodiment the removable slides are housed in lead-lined pockets and beneath a lead-lined, hinged cover member

  5. Monte Carlo method for dose calculation due to oral X-rays

    International Nuclear Information System (INIS)

    Loureiro, Eduardo Cesar de Miranda

    1998-06-01

    The increasing utilization of oral X-rays, especially in youngsters and children, calls for the assessment of equivalent doses in their organs and tissues. With this purpose, a Monte Carlo code was adapted to simulate an X-ray source irradiating phantoms of the MIRD-5 type with different ages (10, 15 and 40 years old) to calculate the conversion coefficients which transform the exposure at skin to equivalent doses at several organs and tissues of interest. In order to check the computer program, simulations were performed for adult patients using the original code (ADAM.FOR developed at the GSF-Germany) and the adapted program (MCDRO.PAS). Good agreement between results obtained with both codes was observed. Irradiations of the incisive, canine and molar teeth were simulated. The conversion factors were calculated for the following organs and tissues: thyroid, active bone narrow (head and whole body), bone (facial skeleton, cranium and whole body), skin (head and whole body) and crystalline. Based on the obtained results, it follows that the younger the patient and the larger the field area, the higher the dose in assessed organs and tissues. The variation of the source-skin distance does not change the conversion coefficients. On the other hand, the increase in the voltage applied to the X-ray tube causes an increase in the calculated conversion coefficients. (author)

  6. A method to test the performance of an energy-dispersive X-ray spectrometer (EDS).

    Science.gov (United States)

    Hodoroaba, Vasile-Dan; Procop, Mathias

    2014-10-01

    A test material for routine performance evaluation of energy-dispersive X-ray spectrometers (EDS) is presented. It consists of a synthetic, thick coating of C, Al, Mn, Cu, and Zr, in an elemental composition that provides interference-free characteristic X-ray lines of similar intensities at 10 kV scanning electron microscope voltage. The EDS energy resolution at the C-K, Mn-Lα, Cu-Lα, Al-K, Zr-Lα, and Mn-Kα lines, the calibration state of the energy scale, and the Mn-Lα/Mn-Kα intensity ratio as a measure for the low-energy detection efficiency are calculated by a dedicated software package from the 10 kV spectrum. Measurements at various input count rates and processor shaping times enable an estimation of the operation conditions for which the X-ray spectrum is not yet corrupted by pile-up events. Representative examples of EDS systems characterized with the test material and the related software are presented and discussed.

  7. Radiation ray discrimination method using photo-stimulated luminescence fluorescent material

    International Nuclear Information System (INIS)

    Atsumi, Yoshihiro; Takebe, Masahiro; Abe, Ken.

    1996-01-01

    An IP (imaging plate) using PSL (photo-stimulated luminescence fluorescent material) is formed by coating a photo-stimulated luminescence fluorescent material on a thin plastic plate. A predetermined colorants is added to the PSL material. A colorant which absorbs a light having a wavelength of about 600nm is preferred. After irradiating various kinds of radiation rays to the IP, and then irradiating a white light thereto for a predetermined period of time, lights at several kinds of wavelength specific to several kinds of radiation rays to be measured are successively irradiated to the IP. The ratios between the luminance intensity of the fluorescent light emitted from the IP in this case and that emitted when a light of one specific wavelength is irradiated are successively calculated. The light of the specific wavelength preferably has a wavelength of 600nm. With such procedures, the kinds of the several radiation rays which are irradiated to the IP can be discriminated. (I.N.)

  8. Provenance studies of archaeological ceramics from Mar-Takla (Ain-Minin, Syria) using radioisotope X-ray fluorescence method

    International Nuclear Information System (INIS)

    Bakraji, E.H.; Othman, I.; Karajou, J.

    2001-01-01

    The radioisotope X-ray fluorescence method was applied to studies of the provenance of the ceramics fragments originated from the Mar-Takla site in Syria. The samples were irradiated 1000s by a 109 Cd radioisotope source and 13 elements (Ca, Ti, Mn, Fe, Zn, Ga, As, Rb, Sr, Y, Zr and Pb) were determined in 35 samples. The data were subjected to two multivariate statistical methods, cluster and principal components analysis (PCA). It was shown from the combination of the statistical techniques and the determination of elemental composition of the samples that 94% of the ceramic samples analyzed can be considered to be manufactured using two sources of raw materials

  9. Provenance studies of archaeological ceramics from Mar-Takla (Ain-Minin, Syria) using radioisotope x-ray fluorescence method

    International Nuclear Information System (INIS)

    Bakraji, E. H.; Karajou, J.; Othman, I.

    2002-01-01

    The radioisotope x-ray fluorescence method was applied to provenance studies of ceramics fragments originated from the Mar-Takla site in Syria. 35 samples were analyzed, where each sample was irradiated 1000 s by sup 1 sup 0 sup 9 Cd radioisotope source and the elements (As, Ca, fe, Ga, Nb, Mn, Pb, Rb, Sr, Ti, Y, Zn, and Zr) were determined. The data were subjected to two multivariate statistical methods, cluster and principal component analysis (PCA). The study show that 94% of the samples can be considered to be manufactured using two sources of raw materials. (Authors)

  10. Mathematical methods in the problem of reconstruction of hadron interaction characteristics and primary cosmic ray spectra at superhigh energies

    International Nuclear Information System (INIS)

    Astaf'ev, V.A.

    1985-01-01

    The paper reviews the mathematical methods used for analyzing the experimental data obtained in investigations of cosmic rays of superhigh energies (10 14 -10 19 eV). The analysis is carried out on the basis of the direct problem solution, i.e. calculation of the characteristics of nuclear-electromagnetic cascade showers developed in the atmosphere with regard to the specific features of experimental devices. The analytical and numerical metods for solving equations describing shower development, as well as simulation of cascade processes by the Monte Carlo method are applied herein

  11. An X-ray fluorescence method for the determination of Ba, Sr, Mo and Bi in thorium oxide

    International Nuclear Information System (INIS)

    Dixit, R.M.; Deshpande, S.S.

    1988-01-01

    A simple and rapid X-ray fluorescence method for the determination of Ba, Sr, Mo and Bi in thoria is described. Thorium oxide samples are dry-mixed thoroughly with pure boric acid in the ratio of 9:1. One gram of mixture is pressed as a double layer over a primary boric acid pellet. The precision and accuracy of the method have been determined. The power limits of detection are found to be around 20 ppm for most analytes. (author). 5 tables

  12. Analysis of x-ray reflectivity data from low-contrast polymer bilayer systems using a Fourier method

    International Nuclear Information System (INIS)

    Seeck, O. H.; Kaendler, I. D.; Tolan, M.; Shin, K.; Rafailovich, M. H.; Sokolov, J.; Kolb, R.

    2000-01-01

    X-ray reflectivity data of polymer bilayer systems have been analyzed using a Fourier method which takes into account different limits of integration in q-space. It is demonstrated that the interfacial parameters can be determined with high accuracy although the difference in the electron density (the contrast) of the two polymers is extremely small. This method is not restricted to soft-matter thin films. It can be applied to any reflectivity data from low-contrast layer systems. (c) 2000 American Institute of Physics

  13. Study of a proposed method of uranium concentration determination using low-energy γ-ray spectroscopy

    International Nuclear Information System (INIS)

    Rossiter, K.G.; Tang, J.C.N.

    1980-01-01

    The problems associated with in-situ uranium assaying are discussed, especially in relation to the secular disequilibrium between the parent uranium and its radioactive daughters. A detailed study of the gamma-spectra of some natural uranium bearing ore and mineral samples was performed using a high resolution Ge(Li) detector. A method of spectroscopic analysis of the low energy gamma-rays of U-238 and its daughter Th-234, using a proportional counter and a series of Ross filters, was found to be feasible. The application of such a method to uranium assaying in natural ore bodies is discussed

  14. A comparison of properties between carboxylated acrylic rubbers prepared by γ-ray irradiation and chemical method

    International Nuclear Information System (INIS)

    Wang Weiwei; Chang Zhenqi; Wang Mozhen; Zhang Zhicheng; Lv Pin

    2006-01-01

    Acrylic rubbers (ACM) carboxylated by acrylic acid or itaconic acid were prepared by 60 Co γ-ray or chemical-initiator (K 2 S 2 O 8 ) induced emulsion copolymerization. The polymers were characterized by Fourier transform infrared spectroscopy (FT-IR). Acid value, molecular weight and polydispersity index (PDI) of the polymers were determined by non-aqueous titration method and gel permeation chromatography (GPC), respectively. Vulcanization and mechanical properties of the filled ACM were studied by rheometric measurement, gel fraction analysis, mechanical property tests and dynamic mechanical thermal analysis (DMTA). The results show that the ACMs prepared by γ-ray irradiation have lower acid value, higher molecular weight and narrower PDI than chemically prepared ACMs of the same compositions. The itaconic acid carboxylated ACM has better cure characteristics and mechanical properties than the acrylic acid carboxylated ACM. The itaconic acid carboxylated ACM prepared by γ-ray irradiation has higher gel fraction and better cure characteristics as well as mechanical properties than that prepared by chemical method. (authors)

  15. X-ray imaging using amorphous selenium: a photoinduced discharge readout method for digital mammography.

    Science.gov (United States)

    Rowlands, J A; Hunter, D M; Araj, N

    1991-01-01

    A new digital image readout method for electrostatic charge images on photoconductive plates is described. The method can be used to read out images on selenium plates similar to those used in xeromammography. The readout method, called the air-gap photoinduced discharge method (PID), discharges the latent image pixel by pixel and measures the charge. The PID readout method, like electrometer methods, is linear. However, the PID method permits much better resolution than scanning electrometers while maintaining quantum limited performance at high radiation exposure levels. Thus the air-gap PID method appears to be uniquely superior for high-resolution digital imaging tasks such as mammography.

  16. Study of imperfect natural diamonds with the application of the X-ray synchrotron radiation (the 'Laue-SR' method)

    CERN Document Server

    Rylov, G M; Sobolev, N V; Kulipanov, G N; Kondratyev, V I; Tolochko, B P; Sharafutdinov, M R

    2001-01-01

    The 'Laue-SR' method has been realised for fast gathering experimental data in the study of imperfect natural and synthesised diamonds which are hard to investigate with the conventional X-ray methods. Time to obtain a diffraction pattern with the use of the polychromatic SR is shorter by several orders; the resolution of the image of substructure defects of a crystal lattice (as compared to the conventional Laue method) is improved by an order and does not vanish even at large disorientation or other non-coherent disturbances of the crystal lattice. The 'Laue-SR' method is especially appropriate for the study of intact, sufficiently large diamond crystals (up to 5 mm), since the diamond has a small coefficient of the X-ray absorption and is practically transparent in the operational range of the SR waves, lambda=0.5-1.5 A. This method was shown to be applied successfully for an accelerated study of a large bulk of imperfect natural diamond crystals without any preliminary preparation and without their destru...

  17. Physical methods for studying minerals and solid materials: X-ray, electron and neutron diffraction; scanning and transmission electron microscopy; X-ray, electron and ion spectrometry

    International Nuclear Information System (INIS)

    Eberhart, J.-P.

    1976-01-01

    The following topics are discussed: theoretical aspects of radiation-matter interactions; production and measurement of radiations (X rays, electrons, neutrons); applications of radiation interactions to the study of crystalline materials. The following techniques are presented: X-ray and neutron diffraction, electron microscopy, electron diffraction, X-ray fluorescence analysis, electron probe microanalysis, surface analysis by electron emission spectrometry (ESCA and Auger electrons), scanning electron microscopy, secondary ion emission analysis [fr

  18. Simulation of the Interaction of X-rays with a Gas in an Ionization Chamber by the Monte Carlo Method

    International Nuclear Information System (INIS)

    Grau Carles, A.; Garcia Gomez-Tejedor, G.

    2001-01-01

    The final objective of any ionization chamber is the measurement of the energy amount or radiation dose absorbed by the gas into the chamber. The final value depends on the composition of the gas, its density and temperature, the ionization chamber geometry, and type and intensity of the radiation. We describe a Monte Carlo simulation method, which allows one to compute the dose absorbed by the gas for a X-ray beam. Verification of model has been carried out by simulating the attenuation of standard X-ray radiation through the half value layers established in the ISO 4037 report, while assuming a Weibull type energy distribution for the incident photons. (Author) 6 refs

  19. Measurement of gamma ray from fuel of high temperature engineering test reactor. Method of measurement and results

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Nozomu; Nojiri, Naoki; Takada, Eiji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2001-02-01

    To obtain information in the HTTR core directly, gamma ray from fuel blocks was measured when fuel blocks were discharged from the core and reloaded to the core. Gamma ray was measured using GM detector, CZT semiconductor detector installed in a door valve and area monitors installed in a stand pipe compartment. The measurement was carried out for 20 fuel blocks in 4 columns considering the symmetry of uranium enrichment distribution in the core. Relative axial distribution in each column obtained by the GM detector and CZT detector agreed with calculated results. However, calculation values showed higher values than measured values in upper region of the core, lower those in lower region of the core. The axial distributions were also evaluated by the area monitors. The measured values agreed with calculated values. It became clear that it was possible to obtain the data inside the core by this method. (author)

  20. X-ray absorption spectroscopy of ultramarine pigments: A new analytical method for the polysulfide radical anion S3- chromophore

    International Nuclear Information System (INIS)

    Fleet, Michael E.; Liu, Xi

    2010-01-01

    Blue and mauve ultramarine artists' pigments and their heat-treated products have been investigated by sulfur K-edge X-ray absorption. X-ray absorption near-edge structure spectra are dominated by features of reduced sulfur and sulfate species. There is also a pre-peak at about 2468.0 eV which reflects the presence of the unpaired electron on the polysulfide radical anion (S 3 - ). Pre-peak intensity is directly proportional to the depth of blue coloration, and provides a new, independent method for estimating the proportion of ultramarine cage sites occupied by the blue chromophore. The occupancy of the polysulfide radical anion S 3 - is estimated to be 33% in an intense ultramarine blue pigment, 22% in a dark blue ultramarine pigment, and 1% in deep royal blue lazurite from Afghanistan. The more efficient development of color in lazurite is attributed to extensive annealing of the mineral structure in the natural environment.

  1. Study of the analytical method based on charged particle excitation of elements and detection on the characteristic X-rays

    International Nuclear Information System (INIS)

    Poncet, Maryse; Engelmann, Charles

    1975-01-01

    Preliminary results obtained by bombarding thick or thin targets with protons of energies below 1.5 MeV are presented. In the former case, curves representing X-ray emission versus proton energy (between 0.4 and 1.4MeV) were determined for 12 elements (Al, Ti, V, Fe, Ni, Cu, Nb, Ag, Sn, W, Au, Pb). From these curves the variation in detection sensitivity with atomic number for a given energy was derived. For some elements (Cu, Ag, Sn, Pb), deposited in thin layers on a aluminium substrate, the X-ray emission was studied as a function of thickness at constant energy. The results show that the method may be used to determine elements of atomic number near 30, in thin layers at least 200μg.cm -2 thick, with a detection limit which could reach a few 10 -3 μg.cm -2 [fr

  2. Calculation of organ doses from environmental gamma rays using human phantoms and Monte Carlo methods. Pt. 1

    International Nuclear Information System (INIS)

    Saito, K.; Petoussi, N.; Zankl, M.; Veit, R.; Jacob, P.; Drexler, G.

    1990-01-01

    Organ doses from environmental γ-rays (U-238, Th-232, K-40) were calculated using Monte Carlo methods for three typical sources of a semi-infinite volume source in the air, an infinite plane source in the ground and a volume source in the ground. γ-ray fields in the natural environment were simulated rigourously without approximations or simplifications in the intermediate steps except for the disturbance of the radiation field by the human body which was neglected. Organ doses were calculated for four anthropomorphic phantoms representing a baby, a child, a female and a male adult. The dose of a fetus is given by the dose to the uterus of the adult female. Air kerma and dose conversion factors normalised to air kerma and to source intensity are given for monoenergetic sources and for the natural radionuclides. (orig./HP)

  3. Methods of X-ray CT image reconstruction from few projections

    International Nuclear Information System (INIS)

    Wang, H.

    2011-01-01

    To improve the safety (low dose) and the productivity (fast acquisition) of a X-ray CT system, we want to reconstruct a high quality image from a small number of projections. The classical reconstruction algorithms generally fail since the reconstruction procedure is unstable and suffers from artifacts. A new approach based on the recently developed 'Compressed Sensing' (CS) theory assumes that the unknown image is in some sense 'sparse' or 'compressible', and the reconstruction is formulated through a non linear optimization problem (TV/l1 minimization) by enhancing the sparsity. Using the pixel (or voxel in 3D) as basis, to apply the CS framework in CT one usually needs a 'sparsifying' transform, and combines it with the 'X-ray projector' which applies on the pixel image. In this thesis, we have adapted a 'CT-friendly' radial basis of Gaussian family called 'blob' to the CS-CT framework. The blob has better space-frequency localization properties than the pixel, and many operations, such as the X-ray transform, can be evaluated analytically and are highly parallelizable (on GPU platform). Compared to the classical Kaisser-Bessel blob, the new basis has a multi-scale structure: an image is the sum of dilated and translated radial Mexican hat functions. The typical medical objects are compressible under this basis, so the sparse representation system used in the ordinary CS algorithms is no more needed. 2D simulations show that the existing TV and l1 algorithms are more efficient and the reconstructions have better visual quality than the equivalent approach based on the pixel or wavelet basis. The new approach has also been validated on 2D experimental data, where we have observed that in general the number of projections can be reduced to about 50%, without compromising the image quality. (author) [fr

  4. Flux decay during thermonuclear X-ray bursts analysed with the dynamic power-law index method

    Science.gov (United States)

    Kuuttila, J.; Kajava, J. J. E.; Nättilä, J.; Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E.; Cumming, A.; Poutanen, J.

    2017-08-01

    The cooling of type-I X-ray bursts can be used to probe the nuclear burning conditions in neutron star envelopes. The flux decay of the bursts has been traditionally modelled with an exponential, even if theoretical considerations predict power-law-like decays. We have analysed a total of 540 type-I X-ray bursts from five low-mass X-ray binaries observed with the Rossi X-ray Timing Explorer. We grouped the bursts according to the source spectral state during which they were observed (hard or soft), flagging those bursts that showed signs of photospheric radius expansion (PRE). The decay phase of all the bursts were then fitted with a dynamic power-law index method. This method provides a new way of probing the chemical composition of the accreted material. Our results show that in the hydrogen-rich sources the power-law decay index is variable during the burst tails and that simple cooling models qualitatively describe the cooling of presumably helium-rich sources 4U 1728-34 and 3A 1820-303. The cooling in the hydrogen-rich sources 4U 1608-52, 4U 1636-536, and GS 1826-24, instead, is clearly different and depends on the spectral states and whether PRE occurred or not. Especially the hard state bursts behave differently than the models predict, exhibiting a peculiar rise in the cooling index at low burst fluxes, which suggests that the cooling in the tail is much faster than expected. Our results indicate that the drivers of the bursting behaviour are not only the accretion rate and chemical composition of the accreted material, but also the cooling that is somehow linked to the spectral states. The latter suggests that the properties of the burning layers deep in the neutron star envelope might be impacted differently depending on the spectral state.

  5. Heavy metals analysis in blood by the X-ray fluorescence method

    International Nuclear Information System (INIS)

    Perez Novara, Ana Ma.

    1988-05-01

    The analytical procedure for determination of heavy metals in blood is described. Blood was taken from active smelter workers, samples were stored in special flasks at 2 grades C. After freeze drying, dried samples was analyzed using X-ray fluorescence, sources excited: Pu-238 and Cd-109 was used. Br in Pb interferences were corrected. The agreement of the results with values in similar workers is satisfactory Median Pb level was 42.6 micro grams/100 ml (total blood), Cu was less 2.5 micro grams/g (dry blood) and Zn was 11 micro grams/g (dry blood). (author)

  6. Separation of substandard tin ores by x-ray fluorescence method

    International Nuclear Information System (INIS)

    Kotler, N.I.; Konovalov, V.M.; Kamenskij, Yu.V.; Neverov, A.D.; Ogorodnikov, Yu.V.

    1987-01-01

    Analysis of pure tin ores on X-ray fluorescence separation (XFS) is carried out. The volumes of lump sampling are substantiated; several variants of technical and economical efficiency of XFS application have been calculated. It is shown that at XFS of -400+25 mm classes conditional as to tin content intermediate product with high efficiency factor may be prepared. Separation of -25+10 mm class is unsuitable, as it doesn't allow to increase tin content to conditional, and the process efficiency is low

  7. Homogeneity characterisation of (U,Gd)O2 sintered pellets by X-ray diffraction powder analysis applying Rietveld method

    International Nuclear Information System (INIS)

    Leyva, Ana G.; Vega, Daniel R.; Trimarco, Veronica G.; Marchi, Daniel E.

    1999-01-01

    The (U,Gd)O 2 sintered pellets are fabricated by different methods. The homogeneity characterisation of Gd content seems to be necessary as a production control to qualify the process and the final product. The micrographic technique is the most common method used to analyse the homogeneity of these samples, this method requires time and expertise to obtain good results. In this paper, we propose an analysis of the X-ray diffraction powder patterns through the Rietveld method, in which the differences between the experimental data and the calculated from a crystalline structure model proposed are evaluated. This result allows to determine the cell parameters, that can be correlated with the Gd concentration, and the existence of other phases with different Gd ratio. (author)

  8. Correction factors for the NMi free-air ionization chamber for medium-energy x-rays calculated with the Monte Carlo method

    International Nuclear Information System (INIS)

    Grimbergen, T.W.M.; Dijk, E. van; Vries, W. de

    1998-01-01

    A new method is described for the determination of x-ray quality dependent correction factors for free-air ionization chambers. The method is based on weighting correction factors for mono-energetic photons, which are calculated using the Monte Carlo method, with measured air kerma spectra. With this method, correction factors for electron loss, scatter inside the chamber and transmission through the diaphragm and front wall have been calculated for the NMi free-air chamber for medium-energy x-rays for a wide range of x-ray qualities in use at NMi. The newly obtained correction factors were compared with the values in use at present, which are based on interpolation of experimental data for a specific set of x-ray qualities. For x-ray qualities which are similar to this specific set, the agreement between the correction factors determined with the new method and those based on the experimental data is better than 0.1%, except for heavily filtered x-rays generated at 250 kV. For x-ray qualities dissimilar to the specific set, differences up to 0.4% exist, which can be explained by uncertainties in the interpolation procedure of the experimental data. Since the new method does not depend on experimental data for a specific set of x-ray qualities, the new method allows for a more flexible use of the free-air chamber as a primary standard for air kerma for any x-ray quality in the medium-energy x-ray range. (author)

  9. Structure analysis of InN film using extended X-ray absorption fine structure method

    Energy Technology Data Exchange (ETDEWEB)

    Miyajima, T.; Kobayashi, T.; Hirata, S. [Core Technology Development Center, Core Technology and Network Company, Sony Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014 (Japan); Kudo, Y.; Liu, K.L. [Technology Solutions Center, Sony Corporation, 4-16-1 Okata, Atsugi, Kanagawa 243-0021 (Japan); Uruga, T.; Honma, T. [Japan Synchrotron Radiation Research Institute, Mikazuki-cho, Hyogo 679-5198 (Japan); Saito, Y.; Hori, M.; Nanishi, Y. [Department of Photonics, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan)

    2002-12-01

    We investigated the local atomic structure around In atoms of MBE-grown InN which has a direct bandgap energy of 0.8 eV, using extended X-ray absorption fine structure (EXAFS) oscillation of In K-edge. The signals from the first-nearest neighbor atoms (N) and second-nearest atoms (In) from In atoms were clearly observed and the atomic bond length of In-N and In-In was estimated to be d{sub In-N}=0.215 nm and d{sub In-In}=0.353 nm, respectively. The In-N bond length of d{sub In-In}=0.353 nm was closed to the a-axis lattice constant of a=0.3536 nm, which was determined using X-ray diffraction measurements. The obtained local atomic structure agreed with the calculated ideal structure. We conclude, therefore, that the InN film with a bandgap energy of 0.8 eV has a high structural symmetry in the range of a few A around In atoms. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  10. Structure analysis of InN film using extended X-ray absorption fine structure method

    International Nuclear Information System (INIS)

    Miyajima, T.; Kobayashi, T.; Hirata, S.; Kudo, Y.; Liu, K.L.; Uruga, T.; Honma, T.; Saito, Y.; Hori, M.; Nanishi, Y.

    2002-01-01

    We investigated the local atomic structure around In atoms of MBE-grown InN which has a direct bandgap energy of 0.8 eV, using extended X-ray absorption fine structure (EXAFS) oscillation of In K-edge. The signals from the first-nearest neighbor atoms (N) and second-nearest atoms (In) from In atoms were clearly observed and the atomic bond length of In-N and In-In was estimated to be d In-N =0.215 nm and d In-In =0.353 nm, respectively. The In-N bond length of d In-In =0.353 nm was closed to the a-axis lattice constant of a=0.3536 nm, which was determined using X-ray diffraction measurements. The obtained local atomic structure agreed with the calculated ideal structure. We conclude, therefore, that the InN film with a bandgap energy of 0.8 eV has a high structural symmetry in the range of a few A around In atoms. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  11. Method and apparatus for neutron induced gamma ray logging for lithology identificaion

    International Nuclear Information System (INIS)

    Oliver, D.W.; Culver, R.B.

    1979-01-01

    A pulsed neutron generator in a well logging instrument is pulsed at a clock frequency of 20 KHz. Inelastic scatter gamma rays are detected during a first time interval coinciding with the neutron source being on and capture gamma rays are measured during a second interval subsequent to the end of each neutron burst. Only a single detected pulse, assuming detection occurs, is transmitted during each of the two detection intervals. Sync pulses are generated in the well logging instrument scaled down to a frequency of 200 Hz for transmission to the earth's surface. At the earth's surface, the scaled-down sync pulses are applied to a phase-locked loop system for regenerating the sync pulses to the same frequency as that of the clock frequency used to pulse the neutron source and to open the detection gates in the borehole instrument. The regenerated sync pulses are used in the surface instrumentation to route the pulses occurring in the inelastic interval into one section of a multichannel analyzer memory and the pulses occurring in the capture interval into another section of the multichannel analyzer. The use of memory address decoders, subtractors and ratio circuits enables both a carbon/oxygen ratio and a silicon/calcium ratio to be struck, substantially independent of the chlorine content of the borehole and formation

  12. Burn up determination of IEAR-1 fuel elements by non destructive gamma ray spectrometry method

    International Nuclear Information System (INIS)

    Soares, A.J.

    1977-01-01

    Measurement of nuclear fuel burn up by non destructive gamma ray spectrometry is discussed, and results of such measurements, made at the Instituto de Energia Atomica (IEA), are given. Specifically, the burn up of an MTR (Material Testing Reactor) fuel element removed from the IEAR-1 swimming pool reactor in 1958 is evaluated from the measured Cs-137 activity, which gives a single 661,6 keV gamma ray. Due to the long decay time of the test element, no other fission decay product activity could be detected. Analysis of measurements, made with a 3'' x 3'' NaI(Tl) detector at 330 distinct points of the element, showed the total burn up to 3.3 +- -+ 0.8 mg. This is in agreement with a calculated value. As the maximum temperature of IEAR-1 fuel elements is of the order of 40 0 C, migration effects of Cs-137 was not considered, this being significant only at fuel temperature in excess of 1000 0 C [pt

  13. A new method for information retrieval in two-dimensional grating-based X-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Wang Zhi-Li; Gao Kun; Chen Jian; Ge Xin; Tian Yang-Chao; Wu Zi-Yu; Zhu Pei-Ping

    2012-01-01

    Grating-based X-ray phase contrast imaging has been demonstrated to be an extremely powerful phase-sensitive imaging technique. By using two-dimensional (2D) gratings, the observable contrast is extended to two refraction directions. Recently, we have developed a novel reverse-projection (RP) method, which is capable of retrieving the object information efficiently with one-dimensional (1D) grating-based phase contrast imaging. In this contribution, we present its extension to the 2D grating-based X-ray phase contrast imaging, named the two-dimensional reverse-projection (2D-RP) method, for information retrieval. The method takes into account the nonlinear contributions of two refraction directions and allows the retrieval of the absorption, the horizontal and the vertical refraction images. The obtained information can be used for the reconstruction of the three-dimensional phase gradient field, and for an improved phase map retrieval and reconstruction. Numerical experiments are carried out, and the results confirm the validity of the 2D-RP method

  14. Developments in gamma-ray spectrometry: systems, software, and methods-II. 4. High-Performance Digital Gamma-Ray Spectrometry

    International Nuclear Information System (INIS)

    Michael Momayezi

    2001-01-01

    This paper reviews recent advances in the field of digital spectrometry made by researchers at X-Ray Instrumentation Associates. All XIA spectrometers are based on a core architecture, which employs digitizing the input signal without shaping and applying all basic data processing in real time to the digital data stream coming out of the wave form digitizer. The real-time digital data processing includes filtering, triggering, pileup rejection, and even pulse shape analysis. In this paper we will describe some of those methods that go beyond emulating a conventional analog system in a digital environment. Rather we will concentrate mainly on methods that have no real equivalent in the analog world. In conventional spectrometers pulse pileup recognition is hardwired and serves a single purpose, namely to reject signals that occur too close to each other to allow for a precise measurement of their amplitude. For a digital device, which can also record wave forms, that would be an unfortunate limitation. The study of very short-lived radioactive isotopes is a case in point. If such an isotope is implanted into a detector in which it then decays by charged particle emission, the signature for the sought-after isotope is that of an implant pulse followed by one or more decay pulses from the isotope and its daughters. If the decay products can be absorbed in the same detector channel, as is the case for proton and alpha emitters in a Si-strip detector, then the isotope decay will show up as a pulse train coming from that detector channel. The difficulty usually is to find the few isotopes of interest amongst a huge background of long-lived or stable isotopes. With programmable pileup recognition logic it is possible to trigger specifically on pulse trains, rather than single pulses, thereby picking out very selectively the isotopes of interest. Analyzing the pulse shape of the incoming preamplifier signal proves to be very useful in many applications. The most obvious

  15. Study on the influence of X-ray tube spectral distribution on the analysis of bulk samples and thin films: Fundamental parameters method and theoretical coefficient algorithms

    International Nuclear Information System (INIS)

    Sitko, Rafal

    2008-01-01

    Knowledge of X-ray tube spectral distribution is necessary in theoretical methods of matrix correction, i.e. in both fundamental parameter (FP) methods and theoretical influence coefficient algorithms. Thus, the influence of X-ray tube distribution on the accuracy of the analysis of thin films and bulk samples is presented. The calculations are performed using experimental X-ray tube spectra taken from the literature and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al. (X-Ray Spectrom. 14 (1985) 125-135), Ebel (X-Ray Spectrom. 28 (1999) 255-266), and Finkelshtein and Pavlova (X-Ray Spectrom. 28 (1999) 27-32). In this study, Fe-Cr-Ni system is selected as an example and the calculations are performed for X-ray tubes commonly applied in X-ray fluorescence analysis (XRF), i.e., Cr, Mo, Rh and W. The influence of X-ray tube spectra on FP analysis is evaluated when quantification is performed using various types of calibration samples. FP analysis of bulk samples is performed using pure-element bulk standards and multielement bulk standards similar to the analyzed material, whereas for FP analysis of thin films, the bulk and thin pure-element standards are used. For the evaluation of the influence of X-ray tube spectra on XRF analysis performed by theoretical influence coefficient methods, two algorithms for bulk samples are selected, i.e. Claisse-Quintin (Can. Spectrosc. 12 (1967) 129-134) and COLA algorithms (G.R. Lachance, Paper Presented at the International Conference on Industrial Inorganic Elemental Analysis, Metz, France, June 3, 1981) and two algorithms (constant and linear coefficients) for thin films recently proposed by Sitko (X-Ray Spectrom. 37 (2008) 265-272)

  16. An overview of quantification methods in energy-dispersive X-ray ...

    Indian Academy of Sciences (India)

    methods for thin samples, samples with intermediate thickness and thick ... algorithms and quantification methods based on scattered primary radiation. ... technique for in situ characterization of materials such as contaminated soil, archaeo-.

  17. Application of the nudged elastic band method to the point-to-point radio wave ray tracing in IRI modeled ionosphere

    Science.gov (United States)

    Nosikov, I. A.; Klimenko, M. V.; Bessarab, P. F.; Zhbankov, G. A.

    2017-07-01

    Point-to-point ray tracing is an important problem in many fields of science. While direct variational methods where some trajectory is transformed to an optimal one are routinely used in calculations of pathways of seismic waves, chemical reactions, diffusion processes, etc., this approach is not widely known in ionospheric point-to-point ray tracing. We apply the Nudged Elastic Band (NEB) method to a radio wave propagation problem. In the NEB method, a chain of points which gives a discrete representation of the radio wave ray is adjusted iteratively to an optimal configuration satisfying the Fermat's principle, while the endpoints of the trajectory are kept fixed according to the boundary conditions. Transverse displacements define the radio ray trajectory, while springs between the points control their distribution along the ray. The method is applied to a study of point-to-point ionospheric ray tracing, where the propagation medium is obtained with the International Reference Ionosphere model taking into account traveling ionospheric disturbances. A 2-dimensional representation of the optical path functional is developed and used to gain insight into the fundamental difference between high and low rays. We conclude that high and low rays are minima and saddle points of the optical path functional, respectively.

  18. An X-ray fluorescence method for the determination of small quantities of elements collected on filters

    International Nuclear Information System (INIS)

    Bayon, A.; Diaz-Guerra, J.P.

    1981-01-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000 μg, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for the Ba determination, while As, Hg, Pb, Se and U are better determined with a molybdenum one. For the rest of the elements a tungsten target is prefered. The interferences between AsKαsub(1,2) - PbLαsub(1,2) and CrKαsub(1,2) - Vkβsub(1,3) lines are corrected by applyng specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different X-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (author)

  19. A rapid real-time PCR method to differentiate between mottled skate (Beringraja pulchra) and other skate and ray species.

    Science.gov (United States)

    Kim, Mi-Ra; Kwon, Kisung; Jung, Yoo-Kyung; Kang, Tae Sun

    2018-07-30

    Skates and rays are commercially important fish in South Korea, and among them, Beringraja pulchra has the highest economic value. However, the similar morphological traits among skates and rays are often exploited for seafood fraud. Here, we designed both Beringraja pulchra-specific and skate-universal primer sets, capable of detecting short sequences in the cytochrome oxidase subunit I gene, and developed highly sensitive and reliable quantitative real-time PCR (qPCR) assays to differentiate between Beringraja pulchra and other skate and ray species. AΔCq method based on differences in the amplification efficiency was developed, validated, and then used to confirm the presence of Beringraja pulchra in twenty-six commercial skate products. The averageΔCq value obtained for other skate species (18.94 ± 3.46) was significantly higher than that of Beringraja pulchra (1.18 ± 0.15). For on-site applications, we developed an ultra-fast qPCR assay, allowing for completion of the entire analytical procedure within 30 min. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. An X-ray fluorescence method for the determination of small quantities el elements collected on filters

    International Nuclear Information System (INIS)

    Diaz-Guerra, J.P.; Bayon, A.

    1981-01-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000μg, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for tho Ba determination, while As, Hg, Pb, Se and U are bottler determined with a molybdenum one. For the rest of the elements a tungsten target is preferred. The interferences between AsK α 1 ,2- PbL α 1 ,2 and CrK α 1 ,2-Vkβ 1 ,3 lines are corrected by applying specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different x-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (Author) 7 refs

  1. Comparison of in-situ gamma ray spectrometry measurements with conventional methods in determination natural and artificial nuclides in soil

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Doubal, A. W.

    2010-12-01

    Two nuclear analytical techniques (In-Situ Gamma ray spectrometry and laboratory gamma ray spectrometry) for determination of natural and artificial radionuclides in soil have been validated. The first technique depends on determination of radioactivity content of representative samples of the studied soil after laboratory preparation, while the second technique is based on direct determination of radioactivity content of soil using in-situ gamma-ray spectrometer. Analytical validation parameter such as detection limits, repeatability, reproducibility in addition to measurement uncertainties were estimated and compared for both techniques. Comparison results have shown that the determination of radioactivity in soil should apply the two techniques together where each of techniques is characterized by its low detection limit and uncertainty suitable for defined application of measurement. Radioactive isotopes in various locations were determined using the two methods by measuring 40 k, 238 U,and 137 Cs. The results showed that there are differences in attenuation factors due to soil moisture content differences; wet weight corrections should be applied when the two techniques are compared. (author)

  2. The measurement test of uranium in a uranium-contaminated waste by passive gamma-rays measurement method

    CERN Document Server

    Sukegawa, Y; Ohki, K; Suzuki, S; Yoshida, M

    2002-01-01

    This report is completed about the measurement test and the proofreading of passive gamma - rays measurement method for Non - destructive assay of uranium in a uranium-contaminated waste. The following are the results of the test. 1) The estimation of the amount of uranium by ionization survey meter is difficult for low intensity of gamma-rays emitted from uranium under about 50g. 2) The estimation of the amount of uranium in the waste by NaI detector is possible in case of only uranium, but the estimation from mixed spectrums with transmission source (60-cobalt) is difficult to confirm target peaks. 3) If daughter nuclides of uranium and thorium chain of uranium ore exist, measurement by NaI detector is affected by gamma-rays from the daughter nuclides seriously-As a result, the estimation of the amount of uranium is difficult. 4) The measurement of uranium in a uranium-contaminated waste by germanium detector is possible to estimate of uranium and other nuclides. 5) As to estimation of the amount of uranium...

  3. An empirical method for peak-to-total ratio computation of a gamma-ray detector

    International Nuclear Information System (INIS)

    Cesana, A.; Terrani, M.

    1989-01-01

    A simple expression for peak-to-total ratio evaluation of gamma-ray detectors in the energy range 0.3-10 MeV is proposed. The quantities one needs to know for the computation are: Detector dimensions and chemical composition, photon corss sections and an empirical energy dependent function which is valid for all the detector materials considered. This procedure seems able to produce peak-to-total values with an accuracy comparable with the most sophisticated Monte Carlo calculations. It has been tested using experimental peak-to-total values of Ge, NaI, CsI and BGO detectors but it is reasonable to suppose that it is valid for any detector material. (orig.)

  4. Discrete curved ray-tracing method for radiative transfer in an absorbing-emitting semitransparent slab with variable spatial refractive index

    International Nuclear Information System (INIS)

    Liu, L.H.

    2004-01-01

    A discrete curved ray-tracing method is developed to analyze the radiative transfer in one-dimensional absorbing-emitting semitransparent slab with variable spatial refractive index. The curved ray trajectory is locally treated as straight line and the complicated and time-consuming computation of ray trajectory is cut down. A problem of radiative equilibrium with linear variable spatial refractive index is taken as an example to examine the accuracy of the proposed method. The temperature distributions are determined by the proposed method and compared with the data in references, which are obtained by other different methods. The results show that the discrete curved ray-tracing method has a good accuracy in solving the radiative transfer in one-dimensional semitransparent slab with variable spatial refractive index

  5. Method for obtaining silver nanoparticle concentrations within a porous medium via synchrotron X-ray computed microtomography.

    Science.gov (United States)

    Molnar, Ian L; Willson, Clinton S; O'Carroll, Denis M; Rivers, Mark L; Gerhard, Jason I

    2014-01-21

    Attempts at understanding nanoparticle fate and transport in the subsurface environment are currently hindered by an inability to quantify nanoparticle behavior at the pore scale (within and between pores) within realistic pore networks. This paper is the first to present a method for high resolution quantification of silver nanoparticle (nAg) concentrations within porous media under controlled experimental conditions. This method makes it possible to extract silver nanoparticle concentrations within individual pores in static and quasi-dynamic (i.e., transport) systems. Quantification is achieved by employing absorption-edge synchrotron X-ray computed microtomography (SXCMT) and an extension of the Beer-Lambert law. Three-dimensional maps of X-ray mass linear attenuation are converted to SXCMT-determined nAg concentration and are found to closely match the concentrations determined by ICP analysis. In addition, factors affecting the quality of the SXCMT-determined results are investigated: 1) The acquisition of an additional above-edge data set reduced the standard deviation of SXCMT-determined concentrations; 2) X-ray refraction at the grain/water interface artificially depresses the SXCMT-determined concentrations within 18.1 μm of a grain surface; 3) By treating the approximately 20 × 10(6) voxels within each data set statistically (i.e., averaging), a high level of confidence in the SXCMT-determined mean concentrations can be obtained. This novel method provides the means to examine a wide range of properties related to nanoparticle transport in controlled laboratory porous medium experiments.

  6. A sensitive and quantitative biosensing method for the determination of {gamma}-ray emitting radionuclides in surface water

    Energy Technology Data Exchange (ETDEWEB)

    Wolterbeek, H.Th.; Meer, A.J.G.M. van der [Technische Univ. Delft (Netherlands). Interfacultair Reactor Inst.

    1996-11-01

    A quantitative and sensitive biosensing method has been developed for the determination of {gamma}-ray emitting radionuclides in surface water. The method is based on the concept that at equilibrium the specific radioactivity in the biosensor is equal to the specific radioactivity in water. The method consists of the measurement of both the radionuclide and the element in the biosensor and the determination of the element level in water. This three-way analysis eliminates problems such as unpredictable biosensor behaviour, effects of water elemental composition or further abiotic parameters: what remains is the generally high enrichment (bioaccumulation factor BCF) of elements and radionuclides in the biosensor material. Measurements were performed with floating water plants (Azolla filiculoides Lamk., Spirodela polyrhiza/Lemna sp.) and the fully submerged water plant Ceratophyllum demersum L., which were sampled from ditch water. Concentrations of elements and radionuclides were determined in both water and biosensor plants, using Neutron Activation Analysis (NAA), ICP-MS, and {gamma}-ray spectrometry, respectively. For the latter, both 1 litre samples (Marinelli-geometry) and 1 cm{sup 3} samples (well-type detectors) were applied in measurements. (author).

  7. A sensitive and quantitative biosensing method for the determination of γ-ray emitting radionuclides in surface water

    International Nuclear Information System (INIS)

    Wolterbeek, H.Th.; Meer, A.J.G.M. van der

    1996-01-01

    A quantitative and sensitive biosensing method has been developed for the determination of γ-ray emitting radionuclides in surface water. The method is based on the concept that at equilibrium the specific radioactivity in the biosensor is equal to the specific radioactivity in water. The method consists of the measurement of both the radionuclide and the element in the biosensor and the determination of the element level in water. This three-way analysis eliminates problems such as unpredictable biosensor behaviour, effects of water elemental composition or further abiotic parameters: what remains is the generally high enrichment (bioaccumulation factor BCF) of elements and radionuclides in the biosensor material. Measurements were performed with floating water plants (Azolla filiculoides Lamk., Spirodela polyrhiza/Lemna sp.) and the fully submerged water plant Ceratophyllum demersum L., which were sampled from ditch water. Concentrations of elements and radionuclides were determined in both water and biosensor plants, using Neutron Activation Analysis (NAA), ICP-MS, and γ-ray spectrometry, respectively. For the latter, both 1 litre samples (Marinelli-geometry) and 1 cm 3 samples (well-type detectors) were applied in measurements. (author)

  8. Standard test method for verifying the alignment of X-Ray diffraction instrumentation for residual stress measurement

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the preparation and use of a flat stress-free test specimen for the purpose of checking the systematic error caused by instrument misalignment or sample positioning in X-ray diffraction residual stress measurement, or both. 1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in polycrystalline samples employing measurement of a diffraction peak position in the high-back reflection region, and in which the θ, 2θ, and ψ rotation axes can be made to coincide (see Fig. 1). 1.3 This test method describes the use of iron powder which has been investigated in round-robin studies for the purpose of verifying the alignment of instrumentation intended for stress measurement in ferritic or martensitic steels. To verify instrument alignment prior to stress measurement in other metallic alloys and ceramics, powder having the same or lower diffraction angle as the material to be measured should be prepared in similar fashion...

  9. Measurements of the residual stresses in the welded steel columns based on the x-ray diffraction method, 2

    International Nuclear Information System (INIS)

    Kaneta, Kiyoshi; Nishizawa, Hidekazu; Arashiyama, Masaki.

    1982-01-01

    In order to evaluate the applicability of two kinds of techniques of the X-ray stress analysis, namely, the standard sin 2 psi method and the newly developed phi-sin 2 psi method, bending tests have been performed. The test results have proved that the values of the stresses measured by means of the mechanical devices and of those measured by the two kinds of the X-ray techniques coincide each other. Then, these two methods have been applied to measure the surface residual stresses of the box-typed, welded steel columns and the following conclusions have been drawn. 1. The principal stress of the surface residural stresses is, in most cases, oriented to the rolled directions at the center of the steel plates, and it tends to rotate in the neighborhood of the heat affected zones. 2. Tensile residual stresses of a large magnitude have been observed in the direction parallel to the beads of the weld, and the moderate compressive residual stresses can be detected in the direction normal to the beads. (author)

  10. A computer programme for use in the development of multi-element x-ray-fluorescence methods of analysis

    International Nuclear Information System (INIS)

    Wall, G.J.

    1985-01-01

    A computer programme (written in BASIC) is described for the evaluation of spectral-line intensities in X-ray-fluorescence spectrometry. The programme is designed to assist the analyst while he is developing new analytical methods, because it facilitates the selection of the following evaluation parameters: calculation models, spectral-line correction factors, calibration curves, calibration ranges, and point deletions. In addition, the programme enables the analyst to undertake routine calculations of data from multi-element analyses in which variable data-reduction parameters are used for each element

  11. Combination of ray-tracing and the method of moments for electromagnetic radiation analysis using reduced meshes

    Science.gov (United States)

    Delgado, Carlos; Cátedra, Manuel Felipe

    2018-05-01

    This work presents a technique that allows a very noticeable relaxation of the computational requirements for full-wave electromagnetic simulations based on the Method of Moments. A ray-tracing analysis of the geometry is performed in order to extract the critical points with significant contributions. These points are then used to generate a reduced mesh, considering the regions of the geometry that surround each critical point and taking into account the electrical path followed from the source. The electromagnetic analysis of the reduced mesh produces very accurate results, requiring a fraction of the resources that the conventional analysis would utilize.

  12. A new method of explosive detection based on dual-energy X-ray technology and forward-scattering

    International Nuclear Information System (INIS)

    Zhao Kun; Li Jianmin

    2004-01-01

    Based on dual-energy X-ray technology combined with forward-scattering, a brand new explosive detection method is presented. Dual-energy technology can give the information on the effective atomic number (Z eff ) of an irradiated component, while the intensity of the forward scattered photons can reveal the density information according to our research. Therefore, the existence of the explosive can be effectively identified by combining these two characteristic quantities. Compared with the earlier inspection approaches, the new one has a series of particular advantages, such as high detection rate, low false alarm rate, automatic alarm and so forth. The project is ongoing. (authors)

  13. Study of an X-ray fluorescence thin film method for the determination of uranium in low activity solutions

    International Nuclear Information System (INIS)

    Diaz-Guerra, J. P.

    1980-01-01

    The application of the X-ray fluorescence thin film technique to the uranium determination in nitric solutions for a concentration range from 1 g/l to 100 g/l and activity levels under 5 mCi/ml is studied. The most suited excitation and measurement conditions are also studied and the uranium matrix effect correction, which is performed through the double dilution, α U U interaction coefficient calculation and internal standard methods, is discussed. The specimen preparation is satisfactorily accomplished by using P.V.C. filters fixed on aluminium supports. (Author) 18 refs

  14. Development and applications of k0 based NAA and prompt gamma-ray NAA methods at BARC

    International Nuclear Information System (INIS)

    Acharya, R.; Nair, A.G.C.; Sudarshan, K.; Goswami, A.; Reddy, A.V.R.

    2008-01-01

    A summary of k 0 -based R and D work on neutron activation analysis (NAA), internal mono standard NAA (IM-NAA) and prompt gamma-ray NAA (PGNAA) is presented. The k 0 -based NAA was standardized by characterizing irradiation sites of research reactors, validated using reference materials and applied to samples of different origin. Recently IM-NAA method was developed, validated for small and large size samples and applied for the analysis of large size as well as non-standard geometry samples. Studies on PGNAA included characterization of neutron beam, determinations of detection efficiency and prompt k 0 -factors, and analytical applications. (author)

  15. Fast and simple method for determination of fatty acid methyl esters (FAME) in biodiesel blends using X-ray spectrometry.

    Science.gov (United States)

    Sitko, Rafal; Zawisza, Beata; Kowalewska, Zofia; Kocot, Karina; Polowniak, Marzena

    2011-09-30

    The determination of fatty acid methyl esters (FAME) in diesel fuel blends is an important aspect of production and blending process as well as quality control of distribution operations. In this study, energy-dispersive X-ray fluorescence spectrometer (EDXRF) is used for the first time for determination of FAME in biodiesel blends. The principle of the method is based on intensity difference of X-ray radiation scattered from hydrocarbons and from FAME. The experiment shows that coherent and incoherent radiation, commonly applied for evaluation of the average atomic number of the sample with light matrix, cannot be applied for FAME determination. However, the application of scattered continuous radiation gives excellent correlation between FAME concentration and intensity of scattered radiation. The best results are obtained if continuum is collected in the range of energy between 10.5 and 15.0 keV for rhodium X-ray tube, operated at 35 kV. Linear relationship between the FAME concentration and the inverse of scattered continuous radiation is obtained with the correlation coefficients of 0.999. Standard deviation of measurement is ca. 0.46% (v/v) of FAME and detection limit is 1.2% (v/v) for 600 s counting time and 50% dead-time loss using Si-PIN detector. The investigation shows that crucial issue in determination of FAME in biodiesel blends using EDXRF spectrometer is the precision of measurements resulting from the counting statistics. Therefore, much better results (0.20% (v/v) standard deviation and 0.52% (v/v) detection limit) can be expected if higher intensity of primary radiation is applied and X-ray spectrum is collected by silicon drift detector of high input count rate. For concentration of FAME from 10 to 100% (v/v), the differences between reference method (Fourier transform infrared spectrometry) and the proposed method usually do not exceed 1% (v/v) of FAME. The proposed method is fast, simple and enables FAME determination in wide range of

  16. Phase-based x-ray scattering—A possible method to detect cancer cells in a very early stage

    Energy Technology Data Exchange (ETDEWEB)

    Feye-Treimer, U., E-mail: feye-treimer@helmholtz-berlin.de; Treimer, W. [Department of Mathematics, Physics and Chemistry, University of Applied Sciences, D-13353 Berlin, Germany and Joint Department G-GTOMO, Helmholtz Zentrum fuer Materialien und Energie Berlin, D-14109 Berlin (Germany)

    2014-05-15

    Purpose: This theoretical work contains a detailed investigation of the potential and sensitivity of phase-based x-ray scattering for cancer detection in biopsies if cancer is in a very early stage of development. Methods: Cancer cells in their early stage of development differ from healthy ones mainly due to their faster growing cell nuclei and the enlargement of their densities. This growth is accompanied by an altered nucleus–plasma relation for the benefit of the cell nuclei, that changes the physical properties especially the index of refraction of the cell and the one of the cell nuclei. Interaction of radiation with matter is known to be highly sensitive to small changes of the index of refraction of matter; therefore a detection of such changes of volume and density of cell nuclei by means of high angular resolved phase-based scattering of x rays might provide a technique to distinguish malignant cells from healthy ones ifthe cell–cell nucleus system is considered as a coherent phase shifting object. Then one can observe from a thin biopsy which represents a monolayer of cells (no multiple scattering) that phase-based x-ray scattering curves from healthy cells differ from those of cancer cells in their early stage of development. Results: Detailed calculations of x-ray scattering patterns from healthy and cancer cell nuclei yield graphs and numbers with which one can distinguish healthy cells from cancer ones, taking into account that both kinds of cells occur in a tissue within a range of size and density. One important result is the role and the influence of the (lateral) coherence width of the radiation on the scattering curves and the sensitivity of phase-based scattering for cancer detection. A major result is that a larger coherence width yields a larger sensitivity for cancer detection. Further import results are calculated limits for critical sizes and densities of cell nuclei in order to attribute the investigated tissue to be healthy or

  17. A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Burion, Steve; Funk, Tobias; Speidel, Michael A.

    2013-01-01

    Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm 2 , calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising

  18. Study of Fe-Ni-Si-B alloy and films on its base by X-ray photospectroscopy method

    International Nuclear Information System (INIS)

    Kozlenko, V.G.; Parfenenok, M.A.; Pukhov, I.K.; Shaposhnikov, A.N.; Shirkov, A.V.

    1983-01-01

    By the method of X ray photoelectron spectroscopy the chemical composition of Fe-Ni-Si-B alloy and films on its base prepared by ion-plasma sputtering is investigated. The identity of chemical bonds in film samples and initial target is revealed, realized are in them mostly Fe-B, Ni-C, Si-Si interatomic bonds. It is shown that lono. films contact with atmosphere is the cause of difference of film composition in the near-surface region (up to 100 nm) from its main volume composition

  19. Study on radiation-induced defects in germanium monocrystals by the X-ray diffusive scattering method

    International Nuclear Information System (INIS)

    Malinenko, I.A.; Perelygina, E.A.; Chudinova, S.A.; Shivrin, O.N.

    1979-01-01

    The method of X-ray diffusion scattering was used to study the defective structure of germanium monocrystals exposed to 750 keV proton irradiation with 3.8x10 16 -4.6x10 17 cm -2 doses and subjected to the subsequent annealing at temperatures up to 450 deg C. Detected in the crystals were the complex radiation induced structure characterized with oriented vacancy complexes and results from the both effects: irradiation and annealing. Radiation defect sizes in the section (hhO) have been determined. With increasing the annealing temperature the structure reconstruction resulting in the complex dissociation is observed

  20. A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    Bennun, L.; Greaves, E.D.; Barros, H.; Diaz-Valdes, J.

    2009-01-01

    A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.