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

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.

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.

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.

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)

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.

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

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.

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.

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 ...

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

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.

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)

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)

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)

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

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

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.

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)

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

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

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)

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.

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.)

Calcitonin produces hypercalcemia in leopard sharks.

Science.gov (United States)

Glowacki, J; O'Sullivan, J; Miller, M; Wilkie, D W; Deftos, L J

1985-02-01

Calcitonin was detected by RIA in sera from four marine species, leopard sharks (Triakis semifasciata), horn sharks (Heterodontus francisci), thornback rays (Platyrhinoides triseriata), and kelp bass (Paralabrax clathratus). These animals have levels of calcitonin and calcium higher than freshwater and terrestrial species have. The administration of salmon calcitonin to bass (4 micrograms/kg BW) produced hypocalcemia and hypophosphatemia as has been reported for other bony vertebrates. In marked contrast, calcitonin produced a prompt hypercalcemia in sharks; the average was 9.8% increase in serum calcium in nine animals with no attendant change in phosphorus. These findings demonstrate that calcitonin can increase serum calcium in sharks. Because shark skeleton is composed of cartilage, this hypercalcemic effect of calcitonin does not require a bony skeleton.

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.

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)

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)

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)

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.

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.

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

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.

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.

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.

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

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

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

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

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

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.

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

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

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

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

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

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.

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)

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)

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

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

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)

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.

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.

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)

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.

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

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.

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)

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

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.)

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.

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.

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...

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

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.

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

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.)

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.)

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)

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

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)

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.

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.

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.

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.)

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.

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)

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.

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

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)

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.

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.

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

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.

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).

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.

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.

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

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)

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

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.

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.

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

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

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.)

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.

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.

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)

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.

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)

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.

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)

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

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.)

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.

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)

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

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.).

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.)

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)

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

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)

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

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

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

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...

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.

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)

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.

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.)

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)

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.)

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.

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

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.

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.

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)

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...

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.

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.)

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)

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)

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

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

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

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...

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.

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.

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

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

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.

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.

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.

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.

Evaluation of a X-ray imaging method in micro-fluidics: the case of T-shaped micro-channels filling up

International Nuclear Information System (INIS)

Vabre, A.; Legoupil, S.; Manach, E.; Gal, O.; Colin, St.; Geoffroy, S.; Gue, A.M.

2006-01-01

X-rays methods assessment in micro-fluidics: case of 'T' shaped microchannels filling. Fluid flows within 'T' or 'Y' shaped microchannels are deeply studied in order to develop adapted modeling approaches and experimental techniques. Our technological choice lies on the attenuation measurement of X-ray in matter. The main advantage of this non-intrusive technique is to be implemented on media opaque to visible light. Moreover, X-rays methods may achieve better spatial resolutions as compared to optical methods because of their much lower wavelength. In order to validate this X-ray method, measurements obtained by this technique are compared with direct measurements carried out on similar microchannels. Finally, experimental results are compared with a theoretical model. (author)

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

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)

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)

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)

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

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

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)

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)

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)

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)

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.)

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.

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)

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

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.

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)

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.)

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.

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.

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

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)

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)

Sample analysis using gamma ray induced fluorescent X-ray emission

Energy Technology Data Exchange (ETDEWEB)

Sood, B S; Allawadhi, K L; Gandhi, R; Batra, O P; Singh, N [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1983-01-01

A non-destructive method for the analysis of materials using gamma ray-induced fluorescent x-ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x-rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from /sup 203/Hg and /sup 241/Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical analysis.

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.

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.

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.

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.)

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

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.

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

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.

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

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)

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.

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)

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)

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)

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.

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

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.

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.

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.

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

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.)

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

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)

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

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.

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

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)

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

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.

A new measurement method of actual focal spot position of an x-ray tube using a high-precision carbon-interspaced grid

Science.gov (United States)

Lee, H. W.; Lim, H. W.; Jeon, D. H.; Park, C. K.; Cho, H. S.; Seo, C. W.; Lee, D. Y.; Kim, K. S.; Kim, G. A.; Park, S. Y.; Kang, S. Y.; Park, J. E.; Kim, W. S.; Woo, T. H.; Oh, J. E.

2018-06-01

This study investigated the effectiveness of a new method for measuring the actual focal spot position of a diagnostic x-ray tube using a high-precision antiscatter grid and a digital x-ray detector in which grid magnification, which is directly related to the focal spot position, was determined from the Fourier spectrum of the acquired x-ray grid’s image. A systematic experiment was performed to demonstrate the viability of the proposed measurement method. The hardware system used in the experiment consisted of an x-ray tube run at 50 kVp and 1 mA, a flat-panel detector with a pixel size of 49.5 µm, and a high-precision carbon-interspaced grid with a strip density of 200 lines/inch. The results indicated that the focal spot of the x-ray tube (Jupiter 5000, Oxford Instruments) used in the experiment was located approximately 31.10 mm inside from the exit flange, well agreed with the nominal value of 31.05 mm, which demonstrates the viability of the proposed measurement method. Thus, the proposed method can be utilized for system’s performance optimization in many x-ray imaging applications.

An experimental implementation of the 90 .deg. compton scattering inspection method for identifying explosive materials using dual energy x-ray

International Nuclear Information System (INIS)

Park, Ji Sung

2012-02-01

In order to obtain the physical properties of an inspection object using an X-ray source, the energy-resolving X-ray method, reflecting the characteristic of continuous energy, is a very useful tool. In this study, the effective atomic number (Z eff ) and normal density (ρ) obtained by the source weighting method on a dual energy X-ray inspection system are presented and demonstrated by experimental implementation. Two X-ray beams of the suggested method were designed using the XCOMP5r code. The filter design of a high energy X-ray source was fixed as 3.5 mm Sn at 150 kVp tube voltage, and the new high energy X-ray beam was named as IN150. The filter design of a low energy X-ray source was also fixed as 0.5 mm Sn at 90 kVp tube voltage, and the new beam was named as IN90. Benchmark calculations by MCNP simulation experiments were performed using four different materials, i.e., Polyethylene, Acetal, Urethane, and TNT. The results of the benchmark calculation showed that the new method can estimate the effective atomic number and the normal density of a scattered object accurately, even when the object was arbitrarily located in samples. Finally to verify the proposed new method, scattering experiments using various polymerized compounds were carried out. The effective attenuation coefficients (μ 1 , μ 2 ) of the experiment objects at the source energies E 1 and E 2 , were calculated using scattered spectra. The effective atomic number and the normal density were then calculated by using the ratio of μ 1 to μ 2 . As a result in case of all sample geometries, the relative differences between the calculation value and the reference value for the effective atomic numbers of each material were within 14 %, and the relative differences for the normal densities were within 12 %. This observation led us to the conclusion that the new 90 .deg. Compton scattering method for identifying explosive materials using a dual-energy X-ray is valid for calculating effective

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)

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

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

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...

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.

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.

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

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...

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)

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)

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.

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.

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

Material Discriminated X-Ray CT System by Using New X-Ray Imager with Energy Discriminate Function

Directory of Open Access Journals (Sweden)

Toru Aoki

2008-04-01

Full Text Available Material discriminated X-ray CT system has been constructed by using conventional X-ray tube (white X-ray source and photon-counting X-ray imager as an application with energy band detection. We have already reported material identify X-ray CT using K-shell edge method elsewhere. In this report the principle of material discrimination was adapted the separation of electron-density and atomic number from attenuation coefficient mapping in X-ray CT reconstructed image in two wavelength X-ray CT method using white X-ray source and energy discriminated X-ray imager by using two monochrome X-ray source method. The measurement phantom was prepared as four kinds material rods (Carbon(C, Iron(Fe, Copper(Cu, Titanium(Ti rods of 3mm-diameter inside an aluminum(Al rod of 20mm-diameter. We could observed material discriminated X-ray CT reconstructed image, however, the discrimination properties were not good than two monochrome X-ray CT method. This results was could be explained because X-ray scattering, beam-hardening and so on based on white X-ray source, which could not observe in two monochrome X-ray CT method. However, since our developed CdTe imager can be detect five energy-bands at the same time, we can use multi-band analysis to decrease the least square error margin. We will be able to obtain more high separation in atomic number mapping in X-ray CT reconstructed image by using this system.

Modern X-ray difraction. X-ray diffractometry for material scientists, physicists, and chemicists

International Nuclear Information System (INIS)

Spiess, L.; Schwarzer, R.; Behnken, H.; Teichert, G.

2005-01-01

The book yields a comprehensive survey over the applications of X-ray diffraction in fields like material techniques, metallurgy, electrotechniques, machine engineering, as well as micro- and nanotechniques. The necessary fundamental knowledge on X-ray diffraction are mediated foundedly and illustratively. Thereby new techniques and evaluation procedures are presented as well as well known methods. The content: Production and properties of X radiation, diffraction of X radiation, hardware for X-ray diffraction, methods of X-ray diffraction, lattice-constant determination, phase analysis, X-ray profile analysis, crystal structure analysis, X-ray radiographic stress analysis, X-ray radiographic texture analysis, crystal orientation determination, pecularities at thin films, small angle scattering

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

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)

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

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)

The application study on the prospecting for gold by car-borne gamma-ray spectrometric method in northern Hebei and other areas

International Nuclear Information System (INIS)

Ma Zhongxiang; Liu Tengyao; Zhang Peng; Lu Shili; Zhai Yugui; Ma Yanfang

1995-01-01

The prospecting method for gold by car-borne gamma-ray spectrometric survey is a new geophysical and geochemical technique in the search for concealed gold deposits which can be used to effectively predict the regional gold metallogenetic potential area. The method of car-borne gamma-ray spectrometric survey was adopted and 63416 data at gamma-ray spectrometric measuring sites from rock masses (or strata) in northern Hebei and other areas (49100 km 2 ) are obtained. On the basis of the size of geological bodies, the sliding filtering technique was applied to process the gamma-ray spectrometric data from regional geological bodies and maps showing the parameter distribution characteristics were plotted (11 sheets). In accordance with the thorough on the distribution characteristics of gamma-ray spectrometric parameters that reflect the regional geological environment of gold metallogenesis, a set of gamma-ray spectrometric combination parameters in correlation with regional gold metallogenesis has been established and the characteristic information of gamma-ray spectrometric parameters has been extracted. Combined with geological information, the gold metallogenetic geological environment in the working area was studied, and two potential areas were predicted. After verification, gold mineralization was encountered in some areas. The study results show that the car-borne gamma-ray spectrometric method used for regional gold prospecting is a rapid, economical and effective one

Precise material identification method based on a photon counting technique with correction of the beam hardening effect in X-ray spectra

International Nuclear Information System (INIS)

Kimoto, Natsumi; Hayashi, Hiroaki; Asahara, Takashi; Mihara, Yoshiki; Kanazawa, Yuki; Yamakawa, Tsutomu; Yamamoto, Shuichiro; Yamasaki, Masashi; Okada, Masahiro

2017-01-01

The aim of our study is to develop a novel material identification method based on a photon counting technique, in which the incident and penetrating X-ray spectra are analyzed. Dividing a 40 kV X-ray spectra into two energy regions, the corresponding linear attenuation coefficients are derived. We can identify the materials precisely using the relationship between atomic number and linear attenuation coefficient through the correction of the beam hardening effect of the X-ray spectra. - Highlights: • We propose a precise material identification method to be used as a photon counting system. • Beam hardening correction is important, even when the analysis is applied to the short energy regions in the X-ray spectrum. • Experiments using a single probe-type CdTe detector were performed, and Monte Carlo simulation was also carried out. • We described the applicability of our method for clinical diagnostic X-ray imaging in the near future.

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...

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.

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)

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.

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

X-ray holography

International Nuclear Information System (INIS)

Faigel, G.; Tegze, M.; Belakhovsky, M.; Marchesini, S.; Bortel, G.

2003-01-01

In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples

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.)

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)

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...

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.)

X-ray filter for x-ray powder diffraction

Science.gov (United States)

Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.; Dooryhee, Eric; Ghose, Sanjit

2018-01-23

Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and walls defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.

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

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

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)

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)

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)

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

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)

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

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

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

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.

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.

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

Method Validation for the Gamma-ray Spectrometric Determination of Natural Radioactive Nuclides in NORM Samples - Method Validation for the Gamma-ray Spectrometric Determination of Natural Radionuclides in raw materials and by-products

Energy Technology Data Exchange (ETDEWEB)

Ji, Young-Yong; Lim, Jong-Myoung; Jang, Mee; Kim, Chang-Jong; Chung, Kun Ho; Kang, Mun Ja; Choi, Geun-Sik [Environmental Radioactivity Assessment Team, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989, Yuseong, Daejeon, 305-353 (Korea, Republic of)

2014-07-01

It has established the 'Act on safety control of radioactive rays around living environment' in Korea, since 2011, to protect the public from natural occurring radioactive materials (NORM) and their by-products. The increasing concerns regarding the radioactivity of those materials therefore dictate many demands for the radioactive analysis for them. There are several methods to determine the concentration of natural radionuclides, such as {sup 235}U, {sup 238}U, {sup 226}Ra, {sup 232}Th, and so on, through a radiochemical analysis using an alpha spectrometer, mass spectrometer and liquid scintillation counter. However, gamma-ray spectroscopy still has an effect on the assessment of radioactive concentration for these nuclides and their progenies. To adapt a gamma spectrometer to the determination of natural radionuclides, the feasibility of their analysis methods should be first verified and validated with respect to accuracy and time and cost constraints. In general, one of the well-known processes in analyzing uranium with a gamma spectrometer is an indirect measurement using the secular equilibrium state with their progenies in a sample. This method, however, demands the time elapsed about 3 weeks to reach the equilibrium state between {sup 226}Ra and {sup 222}Rn and the sufficient integrity of a sample bottle to prevent the leakage of radon isotopes which is a form of noble gas. The simple and quick method is to directly measure a full energy absorption peak of 186.2 keV from {sup 226}Ra without the secular equilibrium state between {sup 226}Ra and {sup 222}Rn in the common sample bottle. However, this direct measurement also has difficulties about the interference with a full energy absorption peak of 185.7 keV from {sup 235}U. In this study, direct measurement with the interference correction technique, which uses several reference peaks for gamma-rays from {sup 235}U and {sup 234}Th, and indirect measurement, which means the identification of {sup

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...

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)

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.).

X-ray diagnostic in gas discharge

International Nuclear Information System (INIS)

Chen Suhe; Wang Dalun; Cui Gaoxian; Wang Mei; Fu Yibei; Zhang Xinwei; Zhang Wushou

1995-01-01

X rays were observed when the anomalous phenomenon in the metal loaded with deuterium studied by the gas-discharge method. Therefore the X-ray energy spectra were measured by the absorption method, the specific X-ray approach and the NaI scintillation counter, while X-ray intensity was estimated by using 7 Li thermoluminescent foils. The X-ray average energy measured by the absorption method is 27.6 +- 2.1 keV, which is fitted within the error extent to 26.0 +-2.4 keV monoenergetic X rays measured by the NaI scintillation counter

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...

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

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)

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)

The development and operation of a method for the remote determination of X-ray beam parameters used in dental radiography

International Nuclear Information System (INIS)

Hewitt, J.M.

1984-07-01

The method described is a part of the Dental Monitoring Service operated by the Board in the UK for the assessment of radiation protection in dental practice. This postal service, which provides a comprehensive survey of dental X-ray sets and radiographic procedures, is undertaken by means of a questionnaire, film cassettes for exposure to the X-ray set and a personal monitoring component to check operator doses. The film cassettes and the methods by which the X-ray beam parameters are obtained are described in detail. The cassettes use radiation monitoring film to realise, by means of measurements of relative transmission through selected copper filters, the extended dynamic range of exposure necessary for accurate indication of the operating kilovoltage and total beam filtration. The standard of the X-ray unit with regard to the relevant regulations and code of practice can then be assessed, and, from the values of radiation dose determined for chosen exposure times, exposure settings for optimum quality radiographs can be recommended where appropriate. Although designed primarily for dental X-ray units, use of the film cassette package may be extended, with suitable calibration, to general diagnostic X-ray survey measurements. (author)

Standard test method for nondestructive assay of special nuclear material in low density scrap and waste by segmented passive gamma-Ray scanning

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method covers the transmission-corrected nondestructive assay (NDA) of gamma-ray emitting special nuclear materials (SNMs), most commonly 235U, 239Pu, and 241Am, in low-density scrap or waste, packaged in cylindrical containers. The method can also be applied to NDA of other gamma-emitting nuclides including fission products. High-resolution gamma-ray spectroscopy is used to detect and measure the nuclides of interest and to measure and correct for gamma-ray attenuation in a series of horizontal segments (collimated gamma detector views) of the container. Corrections are also made for counting losses occasioned by signal processing limitations (1-3). 1.2 There are currently several systems in use or under development for determining the attenuation corrections for NDA of radioisotopic materials (4-8). A related technique, tomographic gamma-ray scanning (TGS), is not included in this test method (9, 10, 11). 1.2.1 This test method will cover two implementations of the Segmented Gamma Scanning ...

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.

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)

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

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

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.

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.

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.)

X-ray interferometric Fourier holography

International Nuclear Information System (INIS)

Balyan, M.K.

2016-01-01

The X-ray interferometric Fourier holography is proposed and theoretically investigated. Fourier The X-ray interferometric Young fringes and object image reconstruction are investigated. It is shown that the interference pattern of two slits formed on the exit surface of the crystal-analyzer (the third plate of the interferometer) is the X-ray interferometric Young fringes. An expression for X-ray interferometric Young fringes period is obtained. The subsequent reconstruction of the slit image as an object is performed by means of Fourier transform of the intensity distribution on the hologram. Three methods of reconstruction of the amplitude transmission complex function of the object are presented: analytical - approximate method, method of iteration and step by step method. As an example the X-ray Fourier interferometric hologram recording and the complex amplitude transmission function reconstruction for a beryllium circular wire are considered

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

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.

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...

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%.

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

Portable X-ray fluorescence analyzer of high sensitivity using X-ray tube excitation

International Nuclear Information System (INIS)

Vatai, E.; Ando, L.

1982-01-01

A review of the three main methods of X-ray fluorescence analysis and their problems is given. The attainable accuracy and effectiveness of each method are discussed. The main properties of portable X-ray analyzers required by the industry are described. The results and experiences of R and D activities in ATOMKI (Debrecen, Hungary) for developing portable X-ray analyzers are presented. The only way for increasing the accuracy and decreasing the measuring time is the application of X-ray tube excitation instead of radioactive sources. The new ATOMKI equipment presently under construction and patenting uses X-ray tube excitation; it will increase the accuracy of concentration determination by one order of magnitude. (D.Gy.)

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

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...

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

Benchtop phase-contrast X-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Gundogdu, O. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Nirgianaki, E.; Che Ismail, E.; Jenneson, P.M.; Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2007-12-15

Clinical radiography has traditionally been based on contrast obtained from absorption when X-rays pass through the body. The contrast obtained from traditional radiography can be rather poor, particularly when it comes to soft tissue. A wide range of media of interest in materials science, biology and medicine exhibit very weak absorption contrast, but they nevertheless produce significant phase shifts with X-rays. The use of phase information for imaging purposes is therefore an attractive prospect. Some of the X-ray phase-contrast imaging methods require highly monochromatic plane wave radiation and sophisticated X-ray optics. However, the propagation-based phase-contrast imaging method adapted in this paper is a relatively simple method to implement, essentially requiring only a microfocal X-ray tube and electronic detection. In this paper, we present imaging results obtained from two different benchtop X-ray sources employing the free space propagation method. X-ray phase-contrast imaging provides higher contrast in many samples, including biological tissues that have negligible absorption contrast.

Effects of X-ray tube parameters on thickness measure precision in X-ray profile gauge

International Nuclear Information System (INIS)

Miao Jichen; Wu Zhifang; Xing Guilai

2011-01-01

Instantaneous profile gauge technology has been widely used in metallurgy industry because it can on-line get the profile of steel strip. It has characters of high measure precision and wide measure range, but the X-ray tube parameters only can be set few different values during measurement. The relations of thickness measure precision and X-ray tube current, X-ray tube voltage were analyzed. The results show that the X-ray tube current affects the thickness measure precision and the X-ray tube voltage determines the thickness measure range. The method of estimating the X-ray current by thickness measure precision was provided in the end. This method is the base of X-ray source selection and X-ray source parameter's setting in the instantaneous profile gauge. (authors)

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

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

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)

Collimatorless imaging of gamma rays with help of gamma-ray tracking

CERN Document Server

Marel, J V D

2001-01-01

In many gamma-ray detector systems that are built for imaging purposes Compton scattered photons are suppressed as much as possible. However, the information from photons that scattered inside a detector system can be used to reconstruct the tracks of the photons with help of gamma-ray tracking. Estimates of the incident directions of the photons can be made and an image can be created. Examples of potential applications for this technique are the use as a gamma-camera in medical imaging (e.g. SPECT) or as a detector for PET. Due to the omission of collimators, much higher detection efficiencies can be achieved, reducing the doses required for an image. A gamma-ray tracking method, called backtracking, has been developed for nuclear spectroscopy. The method tracks gamma-rays originating from a point source in the center of a spherical detector system consisting of position-sensitive germanium detectors. This method can also be used as a tracking technique for imaging of an unknown source distribution. With he...

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

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

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

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

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.

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

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

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)

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.

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)

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

An algorithm to resolve γ-rays from charged cosmic rays with DAMPE

Science.gov (United States)

Xu, Zun-Lei; Duan, Kai-Kai; Shen, Zhao-Qiang; Lei, Shi-Jun; Dong, Tie-Kuang; Gargano, Fabio; Garrappa, Simone; Guo, Dong-Ya; Jiang, Wei; Li, Xiang; Liang, Yun-Feng; Mazziotta, Mario Nicola; Munoz Salinas, Maria Fernanda; Su, Meng; Vagelli, Valerio; Yuan, Qiang; Yue, Chuan; Zang, Jing-Jing; Zhang, Ya-Peng; Zhang, Yun-Long; Zimmer, Stephan

2018-03-01

The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, which was launched on 2015 December 17, is a new high energy cosmic ray and γ-ray satellite-borne observatory. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy γ-rays with accurate energy, angular and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays, it is challenging to identify γ-rays with sufficiently high efficiency, minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at ∼ 10GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.

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

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

Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

International Nuclear Information System (INIS)

Marciszko, Marianna; Baczmański, Andrzej; Braham, Chedly; Wróbel, Mirosław; Wroński, Sebastian; Cios, Grzegorz

2017-01-01

The presented study introduces the development of the multi-reflection grazing-incidence X-ray diffraction method (MGIXD) for residual stress determination. The proposed new methodology is aimed at obtaining more reliable experimental data and increasing the depth of non-destructive stress determination below the sample surface. To verify proposed method measurements were performed on a classical X-ray diffractometer (Cu Kα radiation) and using synchrotron radiation (three different wavelengths: λ = 1.2527 Å, λ = 1.5419 Å and λ = 1.7512 Å). The Al2017 alloy subjected to three different surface treatments was investigated in this study. The obtained results showed that the proposed development of MGIXD method, in which not only different incident angles but also different wavelengths of X-ray are used, can be successfully applied for residual stress determination, especially when stress gradients are present in the sample.

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.

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.

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)

Simulation of transmitted X-rays in a polycapillary X-ray lens

Energy Technology Data Exchange (ETDEWEB)

Peng, Shiqi [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Liu, Zhiguo, E-mail: liuzhiguo512@126.com [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi; Wang, Kai; Yi, Longtao; Yang, Kui; Chen, Man; Wang, Jinbang [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

2015-09-21

The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results.

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

Phase-contrast X-ray imaging using an X-ray interferometer for biological imaging

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi; Koyama, Ichiro [Tokyo Univ., Dept. of Applied Physics, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Inst. of Clinical Medicine, Tsukuba, Ibaraki (Japan); Yoneyama, Akio [Hitachi Ltd., Advanced Research Laboratory, Saitama (Japan)

2002-04-01

The potential of phase-contrast X-ray imaging using an X-ray interferometer is discussed comparing with other phase-contrast X-ray imaging methods, and its principle of contrast generation is presented including the case of phase-contrast X-ray computed tomography. The status of current instrumentation is described and perspectives for practical applications are discussed. (author)

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

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

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.

Spatiotemporal Monte Carlo transport methods in x-ray semiconductor detectors: application to pulse-height spectroscopy in a-Se.

Science.gov (United States)

Fang, Yuan; Badal, Andreu; Allec, Nicholas; Karim, Karim S; Badano, Aldo

2012-01-01

The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The charge transport routines include three-dimensional spatial and temporal models of electron-hole pair transport taking into account recombination and trapping. Many electron-hole pairs are created simultaneously in bursts from energy deposition events. Carrier transport processes include drift due to external field and Coulombic interactions, and diffusion due to Brownian motion. Pulse-height spectra (PHS) have been simulated with different transport conditions for a range of monoenergetic incident x-ray energies and mammography radiation beam qualities. Two methods for calculating Swank factors from simulated PHS are shown, one using the entire PHS distribution, and the other using the photopeak. The latter ignores contributions from Compton scattering and K-fluorescence. Comparisons differ by approximately 2% between experimental measurements and simulations. The a-Se x-ray detector PHS responses simulated in this work include three-dimensional spatial and temporal transport of electron-hole pairs. These PHS were used to calculate the Swank factor and compare it with experimental measurements. The Swank factor was shown to be a function of x-ray energy and applied electric field. Trapping and recombination models are all shown to affect the Swank factor.

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.

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)

X-ray beam generator

International Nuclear Information System (INIS)

Koller, T.J.; Randmer, J.A.

1977-01-01

A method of minimizing the preferential angular absorption of the divergent beam from an X-ray generator is described. The generator consists of an X-ray shielded housing with an X-ray transmissive window symmetrically placed in radial alignment with a focal spot area on a sloped target surface of an X-ray tube in the housing. The X-ray tube may be of the stationary anode type or of the rotating anode type. (U.K.)

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.

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.

Quantitative X-ray methods of amorphous content and crystallinity determination of SiO2, in Quartz and Opal mixture

International Nuclear Information System (INIS)

Ketabdari, M.R.; Ahmadi, K.; Esmaeilnia Shirvani, A.; Tofigh, A.

2001-01-01

X-ray diffraction technique is commonly used for qualitative analysis of minerals, and has also been successfully used for quantitative measurements. In this research, the matrix flushing and a new X-ray diffraction method have been used for the determination of crystallinity and amorphous content of Opal and Quartz mixture. The PCAPD is used to determine the quantitative analysis of these two minerals

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.

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

Duodenal X-ray diagnostics

International Nuclear Information System (INIS)

Scheppach, W.

1982-01-01

The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG) [de

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

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.)

Extending the methodology of X-ray crystallography to allow X-ray microscopy without X-ray optics

International Nuclear Information System (INIS)

Miao Jianwei; Kirz, Janos; Sayre, David; Charalambous, Pambos

2000-01-01

We demonstrate that the soft X-ray diffraction pattern from a micron-size noncrystalline specimen can be recorded and inverted to form a high-resolution image. The phase problem is overcome by oversampling the diffraction pattern. The image is obtained using an iterative algorithm. The technique provides a method for X-ray microscopy requiring no high-resolution X-ray optical elements or detectors. In the present work, a resolution of approximately 60 nm was obtained, but we believe that considerably higher resolution can be achieved

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

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)

Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?

Science.gov (United States)

Heppe, D H M; Taal, H R; Ernst, G D S; Van Den Akker, E L T; Lequin, M M H; Hokken-Koelega, A C S; Geelhoed, J J M; Jaddoe, V W V

2012-02-01

The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots. The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range. Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.

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

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

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...

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

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

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...

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.)

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

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...

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

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...

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)

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.

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.

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.

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.

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.

Comparison of the time behavior in the separation of light and heavy materials in X-ray backscattered method as a diagnostic tool in inspection

International Nuclear Information System (INIS)

Faezeh, Rahmani; Sepideh Sadat, Azimi; Esmaiel, Bayat; Vahid, Dost Mohammadi

2016-01-01

X-ray backscattered method based on Compton backscattering is used in the inspection field. In contrast to transmission method, source and detectors are positioned on one side of the target, so in the situation that transmission inspection is difficult, X-ray backscattered method can be provided suitable data in the inspection field. Also, detection of hidden explosives and narcotic materials are very difficult or impossible in transmission methods. High intensity backscattered beam from light materials (low-Z), such as explosives and narcotics, in comparison to the heavy materials (high-Z), made this method as the strong technique in inspection. X-ray and gamma photons scattered by the light material (such as PE and PTFE) as well as heavy material (such as Fe and Cu) were studied using MCNPX2.6 Monte Carlo code. The results showed that rise time of pulse from light materials are slower than that of from heavy materials due to multi scattering of low energy photons in the light ones, so time expansion would occur in signals from light elements. If measurement is possible, the difference in time behavior can be used as a novel method in complementary diagnostic tool beside the use of pulse height in X-ray backscattered method.

Development of x-ray laminography under an x-ray microscopic condition

International Nuclear Information System (INIS)

Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

2011-01-01

An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

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

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)

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

Atom-resolving x-ray holography

International Nuclear Information System (INIS)

Adams, B.; Hiort, T.; Materlik, G.; Nishino, Y.; Novikov, D. V.

2000-01-01

The current state of atomic resolution x-ray holography is discussed on the basis of theory and experimental results. X-ray holography is theoretically described in quantum theory. Presently-used experimental implementations are shown together with the data analysis used. Reconstructions of experimental and simulated holograms are compared for a Cu 3 Au crystal structure. Rigorous experimental realizations of pure direct and reciprocal x-ray holography methods are demonstrated, and future developments and applications of the method are suggested

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.

VPD residue search by monitoring scattered x-rays

International Nuclear Information System (INIS)

Mori, Y.; Yamagami, M.; Yamada, T.

2000-01-01

Recently, VPD-TXRF has come into wide use for semiconductor analysis. In VPD-TXRF technique, adjusting the mechanical measuring point to the center of dried residue is of importance for accurate determination. Until now, the following searching methods have been used: monitoring light scattering under bright illumination, using laser scattering particle mapper, applying internal standard as a marker. However, each method has individual disadvantage. For example, interference of Kβ line (ex. Sc-Kβ to Ti-Kα) occurs in the internal standard method. We propose a new searching method 'scattered x-ray search' which utilizes x-ray scattering form the dried residue as a marker. Since the line profile of x-ray scattering agrees with that of fluorescent x-rays, scattered x-ray can be used as an alternative marker instead of internal standard. According to our experimental results, this search method shows the same accuracy as internal standard method. The merits are as follows: 1) no need to add internal standard, 2) rapid search because of high intensity of scattered x-rays, 3) searching software for internal standard can be applied without any modification. In this method, diffraction of incident x-rays by substrate causes irregular change over the detected scattering x-rays. Therefore, this method works better under x-y controlled stage than r-Θ one. (author)

New challenges in ray tracing simulations of X-ray optics

International Nuclear Information System (INIS)

Río, M Sánchez del

2013-01-01

The construction of new synchrotron sources and the refurbishment and upgrade of existing ones has boosted in the last years the interest in X-ray optics simulations for beamline design and optimization. In the last years we conducted a full renewal of the well established SHADOW ray tracing code, ending with a modular version SHADOW3 interfaced to multiple programming languages (C, C++, IDL, Python). Some of the new features of SHADOW3 are presented. From the physics point of view, SHADOW3 has been upgraded for dealing with lens systems. X-ray partial coherence applications demand an extension of traditional ray tracing methods into a hybrid ray-tracing wave-optics approach. The software development is essential for fulfilling the requests of the ESRF Upgrade Programme, and some examples of calculations are also presented.

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.

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

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)

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.

Validation of a new background discrimination method for the TACTIC TeV γ-ray telescope with Markarian 421 data

International Nuclear Information System (INIS)

Sharma, Mradul; Nayak, J.; Koul, M.K.; Bose, S.; Mitra, Abhas; Dhar, V.K.; Tickoo, A.K.; Koul, R.

2015-01-01

This paper describes the validation of a new background discrimination method based on Random Forest technique by re-analysing the Markarian 421 (Mrk 421) observations performed by the TACTIC (TeV Atmospheric Cherenkov Telescope with Imaging Camera) γ-ray telescope. The Random Forest technique is a flexible multivariate method which combines Bagging and Random Split Selection to construct a large collection of decision trees and then combines them to construct a common classifier. Markarian 421 in a high state was observed by TACTIC during December 07, 2005–April 30, 2006 for 202 h. Previous analysis of this data led to a detection of flaring activity from the source at Energy >1TeV. Within this data set, a spell of 97 h revealed strong detection of a γ-ray signal with daily flux of >1 Crab unit on several days. Here we re-analyze this spell as well as the data from the entire observation period with the Random Forest method. Application of this method led to an improvement in the signal detection strength by ∼26% along with a ∼18% increase in detected γ rays compared to the conventional Dynamic Supercuts method. The resultant differential spectrum obtained is represented by a power law with an exponential cut off Γ=−2.51±0.10 and E 0 =4.71±2.20TeV. Such a spectrum is consistent with previously reported results and justifies the use of Random Forest method for analyzing data from atmospheric Cherenkov telescopes

Validation of a new background discrimination method for the TACTIC TeV γ-ray telescope with Markarian 421 data

Energy Technology Data Exchange (ETDEWEB)

Sharma, Mradul, E-mail: mradul@barc.gov.in [Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai (India); Nayak, J. [The Bayesian and Interdisciplinary Research Unit, Indian Statistical Institute, Kolkata (India); Koul, M.K. [Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai (India); Bose, S. [The Bayesian and Interdisciplinary Research Unit, Indian Statistical Institute, Kolkata (India); Mitra, Abhas; Dhar, V.K.; Tickoo, A.K.; Koul, R. [Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai (India)

2015-01-11

This paper describes the validation of a new background discrimination method based on Random Forest technique by re-analysing the Markarian 421 (Mrk 421) observations performed by the TACTIC (TeV Atmospheric Cherenkov Telescope with Imaging Camera) γ-ray telescope. The Random Forest technique is a flexible multivariate method which combines Bagging and Random Split Selection to construct a large collection of decision trees and then combines them to construct a common classifier. Markarian 421 in a high state was observed by TACTIC during December 07, 2005–April 30, 2006 for 202 h. Previous analysis of this data led to a detection of flaring activity from the source at Energy >1TeV. Within this data set, a spell of 97 h revealed strong detection of a γ-ray signal with daily flux of >1 Crab unit on several days. Here we re-analyze this spell as well as the data from the entire observation period with the Random Forest method. Application of this method led to an improvement in the signal detection strength by ∼26% along with a ∼18% increase in detected γ rays compared to the conventional Dynamic Supercuts method. The resultant differential spectrum obtained is represented by a power law with an exponential cut off Γ=−2.51±0.10 and E{sub 0}=4.71±2.20TeV. Such a spectrum is consistent with previously reported results and justifies the use of Random Forest method for analyzing data from atmospheric Cherenkov telescopes.

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...

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.

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

Preparation of specimens for analysis by: X-ray diffraction and X-ray fluorescence analysis

International Nuclear Information System (INIS)

Banos L, L.

2004-01-01

Specimen preparation is one of the most important requirements in the analysis of samples by X-ray Diffraction and X-ray Fluorescence. This statement is especially true for samples containing different types of materials. There are many forms of specimen suitable for X-ray analysis and the type of the sample as received will generally determine the method of pretreatment. It is convenient to refer to the material received for analysis as the sample, and that, which is actually analyzed as the specimen. The powder Diffraction method assumes that the particles in the specimen are ideally random orientation and that there are enough crystallites in the specimen to achieve a representative intensity distribution for these crystallites. X ray Fluorescence is essentially a comparative method of analysis, it is vital that all standards and unknowns be presented to the spectrometer in a reproducible and identical manner. (Author) 3 refs., 6 figs

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

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)

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)

X-ray metrology for ULSI structures

International Nuclear Information System (INIS)

Bowen, D. K.; Matney, K. M.; Wormington, M.

1998-01-01

Non-destructive X-ray metrological methods are discussed for application to both process development and process control of ULSI structures. X-ray methods can (a) detect the unacceptable levels of internal defects generated by RTA processes in large wafers, (b) accurately measure the thickness and roughness of layers between 1 and 1000 nm thick and (c) can monitor parameters such as crystallographic texture and the roughness of buried interfaces. In this paper we review transmission X-ray topography, thin film texture measurement, grazing-incidence X-ray reflectivity and high-resolution X-ray diffraction. We discuss in particular their suitability as on-line sensors for process control

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)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

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.

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

Reverse ray tracing for transformation optics.

Science.gov (United States)

Hu, Chia-Yu; Lin, Chun-Hung

2015-06-29

Ray tracing is an important technique for predicting optical system performance. In the field of transformation optics, the Hamiltonian equations of motion for ray tracing are well known. The numerical solutions to the Hamiltonian equations of motion are affected by the complexities of the inhomogeneous and anisotropic indices of the optical device. Based on our knowledge, no previous work has been conducted on ray tracing for transformation optics with extreme inhomogeneity and anisotropicity. In this study, we present the use of 3D reverse ray tracing in transformation optics. The reverse ray tracing is derived from Fermat's principle based on a sweeping method instead of finding the full solution to ordinary differential equations. The sweeping method is employed to obtain the eikonal function. The wave vectors are then obtained from the gradient of that eikonal function map in the transformed space to acquire the illuminance. Because only the rays in the points of interest have to be traced, the reverse ray tracing provides an efficient approach to investigate the illuminance of a system. This approach is useful in any form of transformation optics where the material property tensor is a symmetric positive definite matrix. The performance and analysis of three transformation optics with inhomogeneous and anisotropic indices are explored. The ray trajectories and illuminances in these demonstration cases are successfully solved by the proposed reverse ray tracing method.

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)

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.

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)

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...

[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.

Cosmic ray production curves below reworking zones

International Nuclear Information System (INIS)

Blanford, G.E.

1980-01-01

A method is presented for calculating cosmic ray production profiles below reworking zones. The method uses an input reworking depth determined from data such as signatures in the depth profile of ferromagnetic resonance intensity and input cosmic ray production profiles for an undisturbed surface. Reworking histories are simulated using Monte Carlo techniques, and depth profiles are used to determine cosmic ray exposure age limits with a specified probability. It is shown that the track density profiles predict cosmic ray exposure ages in lunar cores that are consistent with values determined by other methods. Results applied to neutron fluence and spallation rare gases eliminate the use of reworking depth as an adjustable parameter and give cosmic ray exposure ages that are compatible with each other

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

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)

X-ray diffractometric study on the near-surface layer structure in parallel glancing rays

International Nuclear Information System (INIS)

Shtypulyak, N.I.; Yakimov, I.I.; Litvintsev, V.V.

1988-01-01

X-ray diffraction method is suggested to use to investigate thin films and near-surface layers under the conditions of total external reflection (TER) and in the geometry of parallel glancing rays. Experimental realization of the method using the DRON-30 diffractometer is described. Calculation for the required width of the aperture of Soller slot system is presented. The described diffraction scheme is used to investigate thin film crystal structure at glancing angles in the range from TER up to 8-10 deg. The thickness of the investigated layer in this case changes from 2.5-8 nm up to 10 3 nm. The suggested diffraction method in parallel glancing rays is especially important when investigating the films with thickness lower than 1000-2000A

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)

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.

X-ray Absorption Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Yano, Junko; Yachandra, Vittal K.

2009-07-09

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

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...

Extended X-ray absorption fine structure and X-ray diffraction studies on supported Ni catalysts

International Nuclear Information System (INIS)

Aldea, N.; Marginean, P.; Yaning, Xie; Tiandou, Hu; Tao, Liu; Wu, Zhongua; ZhenYa, Dai

1999-01-01

In the first part of this paper, we present a study based on EXAFS spectroscopy. This method can yield structural information about the local environment around a specific atomic constituent in the amorphous materials, the location and chemical state of any catalytic atom on any support or point defect structures, in alloys and composites. EXAFS is a specific technique of the scattering of X-ray on materials. The present study is aimed toward elucidation of the local structure of Ni atoms and their interaction with oxide support. The second goal of the paper consists in X-ray diffraction on the same samples. X-ray diffraction method that is capable to determine average particle size, microstrains, probability of faults as well as particle size distribution function of supported Ni catalysts is presented. The method is based on the Fourier analysis of a single X-Ray diffraction profile. The results obtained on supported nickel catalysts, which are used in H/D isotopic exchange reactions are reported. The global structure is obtained with a new fitting method based on the Generalised Fermi Function facilities for approximation and Fourier transform of the experimental X-Ray line profiles. Both types of measurements were performed on Beijing Synchrotron Radiation Facilities (BSRF). (authors)

X-ray optics and X-ray microscopes: new challenges

International Nuclear Information System (INIS)

Susini, J.

2004-01-01

Soon after the discovery of X-rays in 1895 by W. Roentgen, it became rapidly clear that the methods traditionally used in the visible light regime, namely refraction, diffraction and reflection were difficult to apply for X-ray optics. The physical origins of these difficulties are closely linked to the very nature of interaction of X-rays with matter. The small deviation δ of the refractive index of condensed matter from unity makes it difficult to extend refraction-based optics from the optical spectral region to the X-ray region because the refraction angle is proportional to δ. Similarly it is very challenging to extend diffraction-based focusing techniques to X-rays because the diffraction angle scales inversely with wavelength. Finally, the use of reflection-based optics is also limited by the very small critical angle for total reflection. All those fundamental limitations prevented for almost one century, the development of X-ray microscopy whereas electron microscopy became a standard tool. In the past twenty years, interests for X-ray microscopy revived, mainly because of several major advances in X-ray sources and X-ray optics. X-ray microscopy techniques are now emerging as powerful and complementary tools for submicron investigations. Soft X-ray microscopes offer traditionally the possibility to form direct images of thick hydrated biological material in near-native environment, at a spatial resolution well beyond that achievable with visible light microscopy. Natural contrast is available in the soft X-ray region, in the so-called ''water-window'', due to the presence of absorption edges of the major constituents (C,N,O). Recent advances in manufacturing techniques have enlarged the accessible energy range of micro-focussing optics and offer new applications in a broad range of disciplines. X-ray microscopy in the 1 - 30 keV energy range is better suited for fluorescence to map trace elements, tomography for 3D imaging and micro-diffraction. The

X ray Production. Chapter 5

Energy Technology Data Exchange (ETDEWEB)

Nowotny, R. [Medical University of Vienna, Vienna (Austria)

2014-09-15

The differential absorption of X rays in tissues and organs, owing to their atomic composition, is the basis for the various imaging methods used in diagnostic radiology. The principles in the production of X rays have remained the same since their discovery. However, much refinement has gone into the design of X ray tubes to achieve the performance required for today’s radiological examinations. In this chapter, an outline of the principles of X ray production and a characterization of the radiation output of X ray tubes will be given. The basic processes producing X rays are dealt with in Section 1.4.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. ...

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

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

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

Residual stress analysis of a multi-layer thin film structure by destructive (curvature) and non-destructive (x-ray) methods

International Nuclear Information System (INIS)

Chen, P.C.; Oshida, Y.

1989-01-01

Multi-layer thin film which has structure of Cu/Cr/K/Cr/Cu prepared by sputtering process was analyzed for interfacial stresses for as-deposited conditions. This structure was also annealed at 150 degrees C, and 350 degrees C for around 15 min. in a vacuum and cooled slowly down for stress analyses. Equations for residual stress estimations for homogeneous material system using layer removal technique (stress relief) is now applied for inhomogeneous system (multi-layer structure). The results are compared with the data obtained from x-ray diffraction technique by using sin 2 Ψ - 2 θ method, for Cu layer. From the present analyses, the data obtained using layer removal seem to be qualitatively consistent with but not quantitatively in agreement with x-ray method

Analyses of the internal structure of the oscillating vibro-packed fuels by the micro focus X-rays CT method

International Nuclear Information System (INIS)

Mizuta, Yasutoshi

2003-02-01

The purpose of this study is to support the development of vibro-packed fuel technology at Japan Nuclear Cycle Development Institute. 3-dimensional (3-D) data was built from the multi-cross sectional images obtained by the micro focus X-rays CT method in the vibro-packed fuel models. The structural analyses were carried out about the obtained 3-D CT images. The packing-rate distribution and the density distribution were measured as well as the number distribution of particles, etc. Consequently, it is obtained that vibrate conditions and a vibrating state have strong correlation, and it is also shown that the 3-D analyses of the internal structure by the micro focus X-rays CT method are effective in performance evaluation of vibro-packed fuels. (author)

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)

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)

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)

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)

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)

X-ray spectroscopy and X-ray crystallography of metalloenzymes at XFELs

International Nuclear Information System (INIS)

Yano, Junko

2016-01-01

The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting crystallography data and X-ray emission spectra, using an energy dispersive spectrometer at ambient conditions. In addition, we have developed a way to collect metal L-edge data of dilute samples using soft X-rays at XFELs. The advantages and challenges of these methods will be described in this review. (author)

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.)

Cosmic ray: Studying the origin

International Nuclear Information System (INIS)

Szabelski, J.

1997-01-01

Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10 15 eV (since photons point to their places of origin), studies of the mass composition of cosmic rays (because it reflects source morphology), and studies of cosmic rays with energy above 1O 19 eV (for these are the highest energies observed in nature). (author)

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

Handbook on Mobile Gamma-ray Spectrometry

DEFF Research Database (Denmark)

Aage, Helle Karina; Korsbech, Uffe C C

2003-01-01

Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

Trajectory method in the theory of Laue diffraction of X rays in crystals: II. Effect of total reflection at bending deformation

International Nuclear Information System (INIS)

Kohn, V. G.

2008-01-01

The effect of total reflection (switching) of a spherical X-ray wave in the case of Laue diffraction in a crystal with bending deformation is analyzed by the trajectory method. Qualitative analytical description and computation of the spatial structure of the reflected beam for large and small distances between the spherical-wave source and the crystal are performed. The mechanism of much more efficient reflection of an X-ray beam by a deformed crystal in comparison with a perfect crystal is clearly demonstrated. It is also shown that the trajectory method is very convenient for description of the total reflection phenomenon.

Trajectory method in the theory of Laue diffraction of X rays in crystals: II. Effect of total reflection at bending deformation

International Nuclear Information System (INIS)

Kohn, V. G.

2008-01-01

The effect of total reflection (switching) of a spherical X-ray wave in the case of Laue diffraction in a crystal with bending deformation is analyzed by the trajectory method. Qualitative analytical description and computation of the spatial structure of the reflected beam for large and small distances between the spherical-wave source and the crystal are performed. The mechanism of much more efficient reflection of an X-ray beam by a deformed crystal in comparison with a perfect crystal is clearly demonstrated. It is also shown that the trajectory method is very convenient for description of the total reflection phenomenon

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).

Performance evaluation of X-ray CT using visible scintillation light

International Nuclear Information System (INIS)

Kodama, Kiyoyuki; Hamada, Minoru; Suzuki, Tamotsu; Hashimoto, Masatoshi; Hanada, Takashi; Ide, Tatsuya; Maruyama, Koichi

2004-01-01

We proposed a new method of performance evaluation for X-ray CT using visible scintillation light and examined its usefulness in this study. When we scanned a plastic scintillator disk in a gantry opening of the X-ray CT, we could observe visible scintillation light. The rotation of the light-emitting area of the disk corresponded to that of the X-ray tube. We were able to record the scintillation light by digital video camera. By analyzing the area of visible scintillation light, the rotation speed of the X-ray tube, angular spread of the X-ray beam, uniformity of the incident X-rays, and change in X-ray energy were measured. No other method is available to obtain the above parameters of X-ray CT during a single CT scan. In the measurements of the uniformity of incident X-rays and change of X-ray energy, our method showed good accuracy in detecting the attenuation caused by the couch between the X-ray tube and the plastic scintillator disc. The proposed method is inexpensive and easy-to-use. We conclude that the method is a useful tool for performance evaluation as well as a maintenance tool for X-ray CT. (author)