Journal articles: 'X-ray simulation method'

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Fu, Chao, Ao Dong Shen, and Li Min Luo. "A Fast Ray-Tracing Algorithm for X-Ray Imaging Simulation." Applied Mechanics and Materials 198-199 (September 2012): 1361–66. http://dx.doi.org/10.4028/www.scientific.net/amm.198-199.1361.

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X-ray radiography has more and more application value and X-ray simulation system has practical significance for improving the quality of X-ray imaging and replacing the expensive devices but it’s a time-consuming work. This paper proposes an improved fast ray-tracing method extended from Siddon’s and Zhao’s methods. For a 2D array, we compute level by level which has natural modes, by comparing the incident x-coordinate with the characteristic constant. In the case of 3D models, the volume data are back projected into 1D linked list and compute indices and lengths similarly like the case of 2D. Compared with Zhao’s method, the new method avoids skipping parametric planes and computing several starting voxels and ending voxels in one level. The time consumed in the new algorithm has reduced by 5/6 regarding the conventional Siddon’s algorithm.

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Xue Meng-Fan, Li Xiao-Ping, Sun Hai-Feng, Liu Bing, Fang Hai-Yan, and Shen Li-Rong. "A new simulation method of X-ray pulsar signals." Acta Physica Sinica 64, no. 21 (2015): 219701. http://dx.doi.org/10.7498/aps.64.219701.

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Kim, In, Sang-Wan Ryu, Byung-Doo Choe, Hee-Dae Kim, and Weon Guk Jeong. "Matrix method for the x-ray rocking curve simulation." Journal of Applied Physics 83, no. 7 (April 1998): 3932–34. http://dx.doi.org/10.1063/1.367143.

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Zhang, Hua, Luping Xu, Shibin Song, and Rong Jiao. "A fast method for X-ray pulsar signal simulation." Acta Astronautica 98 (May 2014): 189–200. http://dx.doi.org/10.1016/j.actaastro.2014.01.030.

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Lambert, Sébastien, and François Guillet. "Application of the X-ray tracing method to powder diffraction line profiles." Journal of Applied Crystallography 41, no. 1 (January 16, 2008): 153–60. http://dx.doi.org/10.1107/s0021889807055069.

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An X-ray tracing program was developed to simulate the instrument function of a high-resolution X-ray powder diffractometer. The optics of this laboratory instrument consist of a conventional X-ray tube, a single flat Ge monochromator, slits, the powder sample and finally a curved position-sensitive detector. Such a setup provides an interesting case study in order to assess X-ray tracing, which has seldom been used in the case of laboratory equipment. The simulation reported in this paper covers different aspects of optics simulation, ranging from straightforward kinematic diffraction to dynamic diffraction by single crystals or learned detector response function. The comparison between the simulation and the profiles measured using the NIST line profile standard SRM 660a LaB6shows a good agreement. This result provides the basis for discussing the opportunity of using X-ray tracing in diagram-refinement software.

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Gao, Bo, Brecht Laforce, Jelle Dhaene, Laszlo Vincze, Luc Van Hoorebeke, and Matthieu N. Boone. "An analytical simulation method for X-ray fluorescence computed tomography." Radiation Physics and Chemistry 170 (May 2020): 108622. http://dx.doi.org/10.1016/j.radphyschem.2019.108622.

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Cooper, V. N., J. M. Boone, and J. A. Seibert. "A lesion detectability simulation method for digital x-ray imaging." Medical Physics 27, no. 1 (January 2000): 66–74. http://dx.doi.org/10.1118/1.598872.

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Nazemi, Ehsan, Nathanaël Six, Domenico Iuso, Björn De Samber, Jan Sijbers, and Jan De Beenhouwer. "Monte-Carlo-Based Estimation of the X-ray Energy Spectrum for CT Artifact Reduction." Applied Sciences 11, no. 7 (April 1, 2021): 3145. http://dx.doi.org/10.3390/app11073145.

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Beam hardening and scattering effects can seriously degrade image quality in polychromatic X-ray CT imaging. In recent years, polychromatic image reconstruction techniques and scatter estimation using Monte Carlo simulation have been developed to compensate for beam hardening and scattering CT artifacts, respectively. Both techniques require knowledge of the X-ray tube energy spectrum. In this work, Monte Carlo simulations were used to calculate the X-ray energy spectrum of FleXCT, a novel prototype industrial micro-CT scanner, enabling beam hardening and scatter reduction for CT experiments. Both source and detector were completely modeled by Monte Carlo simulation. In order to validate the energy spectra obtained via Monte Carlo simulation, they were compared with energy spectra obtained via a second method. Here, energy spectra were calculated from empirical measurements using a step wedge sample, in combination with the Maximum Likelihood Expectation Maximization (MLEM) method. Good correlation was achieved between both approaches, confirming the correct modeling of the FleXCT system by Monte Carlo simulation. After validation of the modeled FleXCT system through comparing the X-ray spectra for different tube voltages inside the detector, we calculated the X-ray spectrum of the FleXCT X-ray tube, independent of the flat panel detector response, which is a prerequisite for beam hardening and scattering CT artifacts.

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Venkatakrishnan, S. V., Jeffrey Donatelli, Dinesh Kumar, Abhinav Sarje, Sunil K. Sinha, Xiaoye S. Li, and Alexander Hexemer. "A multi-slice simulation algorithm for grazing-incidence small-angle X-ray scattering." Journal of Applied Crystallography 49, no. 6 (October 14, 2016): 1876–84. http://dx.doi.org/10.1107/s1600576716013273.

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Grazing-incidence small-angle X-ray scattering (GISAXS) is an important technique in the characterization of samples at the nanometre scale. A key aspect of GISAXS data analysis is the accurate simulation of samples to match the measurement. The distorted-wave Born approximation (DWBA) is a widely used model for the simulation of GISAXS patterns. For certain classes of sample such as nanostructures embedded in thin films, where the electric field intensity variation is significant relative to the size of the structures, a multi-slice DWBA theory is more accurate than the conventional DWBA method. However, simulating complex structures in the multi-slice setting is challenging and the algorithms typically used are designed on a case-by-case basis depending on the structure to be simulated. In this paper, an accurate algorithm for GISAXS simulations based on the multi-slice DWBA theory is presented. In particular, fundamental properties of the Fourier transform have been utilized to develop an algorithm that accurately computes the average refractive index profile as a function of depth and the Fourier transform of the portion of the sample within a given slice, which are key quantities required for the multi-slice DWBA simulation. The results from this method are compared with the traditionally used approximations, demonstrating that the proposed algorithm can produce more accurate results. Furthermore, this algorithm is general with respect to the sample structure, and does not require any sample-specific approximations to perform the simulations.

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Bootsma, G. J., H. Nordström, M. Eriksson, and D. A. Jaffray. "Monte Carlo kilovoltage X-ray tube simulation: A statistical analysis and compact simulation method." Physica Medica 72 (April 2020): 80–87. http://dx.doi.org/10.1016/j.ejmp.2020.03.015.

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Canestrari, Niccolo, Oleg Chubar, and Ruben Reininger. "Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics." Journal of Synchrotron Radiation 21, no. 5 (August 6, 2014): 1110–21. http://dx.doi.org/10.1107/s1600577514013058.

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X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick–Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in theSynchrotron Radiation Workshop(SRW) computer code and extensively tested against the geometrical ray-tracing codeSHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between theSRWandSHADOWsimulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

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Song, Shuang, Jian Yang, Jingfan Fan, Weijian Cong, Danni Ai, Yitian Zhao, and Yongtian Wang. "Geometrical force constraint method for vessel and x-ray angiogram simulation." Journal of X-Ray Science and Technology 24, no. 1 (March 1, 2016): 87–106. http://dx.doi.org/10.3233/xst-160539.

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Fevola, Giovanni, Erik Bergbäck Knudsen, Tiago Ramos, Dina Carbone, and Jens Wenzel Andreasen. "A Monte Carlo ray-tracing simulation of coherent X-ray diffractive imaging." Journal of Synchrotron Radiation 27, no. 1 (January 1, 2020): 134–45. http://dx.doi.org/10.1107/s1600577519014425.

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Coherent diffractive imaging (CDI) experiments are adequately simulated assuming the thin sample approximation and using a Fresnel or Fraunhofer wavefront propagator to obtain the diffraction pattern. Although this method is used in wave-based or hybrid X-ray simulators, here the applicability and effectiveness of an alternative approach that is based solely on ray tracing of Huygens wavelets are investigated. It is shown that diffraction fringes of a grating-like source are accurately predicted and that diffraction patterns of a ptychography dataset from an experiment with realistic parameters can be sampled well enough to be retrieved by a standard phase-retrieval algorithm. Potentials and limits of this approach are highlighted. It is suggested that it could be applied to study imperfect or non-standard CDI configurations lacking a satisfactory theoretical formulation. The considerable computational effort required by this method is justified by the great flexibility provided for easy simulation of a large-parameter space.

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Koukou, V., N. Martini, C. Michail, P. Sotiropoulou, C. Fountzoula, N. Kalyvas, I. Kandarakis, G. Nikiforidis, and G. Fountos. "Dual Energy Method for Breast Imaging: A Simulation Study." Computational and Mathematical Methods in Medicine 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/574238.

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Dual energy methods can suppress the contrast between adipose and glandular tissues in the breast and therefore enhance the visibility of calcifications. In this study, a dual energy method based on analytical modeling was developed for the detection of minimum microcalcification thickness. To this aim, a modified radiographic X-ray unit was considered, in order to overcome the limited kVp range of mammographic units used in previous DE studies, combined with a high resolution CMOS sensor (pixel size of 22.5 μm) for improved resolution. Various filter materials were examined based on their K-absorption edge. Hydroxyapatite (HAp) was used to simulate microcalcifications. The contrast to noise ratio (CNRtc) of the subtracted images was calculated for both monoenergetic and polyenergetic X-ray beams. The optimum monoenergetic pair was 23/58 keV for the low and high energy, respectively, resulting in a minimum detectable microcalcification thickness of 100 μm. In the polyenergetic X-ray study, the optimal spectral combination was 40/70 kVp filtered with 100 μm cadmium and 1000 μm copper, respectively. In this case, the minimum detectable microcalcification thickness was 150 μm. The proposed dual energy method provides improved microcalcification detectability in breast imaging with mean glandular dose values within acceptable levels.

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Ouyang, Miang Zhao, Yue Gang Fu, Zhi Ying Liu, Jia Ke Wang, and Wen Jun He. "The Structural Design Method of Multi-Layer Parabolic Reflective Surface for X-Ray Focusing." Key Engineering Materials 552 (May 2013): 75–78. http://dx.doi.org/10.4028/www.scientific.net/kem.552.75.

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As an ultra-short electromagnetic waves, X-ray has a strong ability to penetrate with high-energy. The method for focusing visible spectral bands is not suitable for X-ray spectrum. At present, in X-ray astronomy, the X-ray focus mode which uses grazing incidence less than critical angle has been widely used. However, the small critical angle limits its effective aperture of the X-ray collection. This paper presents a multi-layer reflective structure working with grazing incidence and the surfaces coated multilayer high reflective for X-ray. It can guarantee the large effective entrance pupil and high energy collection. The 200mm diameter X-ray focusing device is designed as an example. It is found from simulation that a good focusing result is acquired.

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Shi, Xianbo, Ruben Reininger, Manuel Sanchez del Rio, and Lahsen Assoufid. "A hybrid method for X-ray optics simulation: combining geometric ray-tracing and wavefront propagation." Journal of Synchrotron Radiation 21, no. 4 (May 15, 2014): 669–78. http://dx.doi.org/10.1107/s160057751400650x.

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A new method for beamline simulation combining ray-tracing and wavefront propagation is described. The `Hybrid Method' computes diffraction effects when the beam is clipped by an aperture or mirror length and can also simulate the effect of figure errors in the optical elements when diffraction is present. The effect of different spatial frequencies of figure errors on the image is compared withSHADOWresults pointing to the limitations of the latter. The code has been benchmarked against the multi-electron version ofSRWin one dimension to show its validity in the case of fully, partially and non-coherent beams. The results demonstrate that the code is considerably faster than the multi-electron version ofSRWand is therefore a useful tool for beamline design and optimization.

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Peter, Silvia, Peter Modregger, Michael K. Fix, Werner Volken, Daniel Frei, Peter Manser, and Marco Stampanoni. "Combining Monte Carlo methods with coherent wave optics for the simulation of phase-sensitive X-ray imaging." Journal of Synchrotron Radiation 21, no. 3 (March 18, 2014): 613–22. http://dx.doi.org/10.1107/s1600577514000952.

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Phase-sensitive X-ray imaging shows a high sensitivity towards electron density variations, making it well suited for imaging of soft tissue matter. However, there are still open questions about the details of the image formation process. Here, a framework for numerical simulations of phase-sensitive X-ray imaging is presented, which takes both particle- and wave-like properties of X-rays into consideration. A split approach is presented where we combine a Monte Carlo method (MC) based sample part with a wave optics simulation based propagation part, leading to a framework that takes both particle- and wave-like properties into account. The framework can be adapted to different phase-sensitive imaging methods and has been validated through comparisons with experiments for grating interferometry and propagation-based imaging. The validation of the framework shows that the combination of wave optics and MC has been successfully implemented and yields good agreement between measurements and simulations. This demonstrates that the physical processes relevant for developing a deeper understanding of scattering in the context of phase-sensitive imaging are modelled in a sufficiently accurate manner. The framework can be used for the simulation of phase-sensitive X-ray imaging, for instance for the simulation of grating interferometry or propagation-based imaging.

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Holstad, Theodor Secanell, Trygve Magnus Ræder, Mads Carlsen, Erik Bergbäck Knudsen, Leora Dresselhaus-Marais, Kristoffer Haldrup, Hugh Simons, Martin Meedom Nielsen, and Henning Friis Poulsen. "X-ray free-electron laser based dark-field X-ray microscopy: a simulation-based study." Journal of Applied Crystallography 55, no. 1 (February 1, 2022): 112–21. http://dx.doi.org/10.1107/s1600576721012760.

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Dark-field X-ray microscopy (DFXM) is a nondestructive full-field imaging technique providing three-dimensional mapping of microstructure and local strain fields in deeply embedded crystalline elements. This is achieved by placing an objective lens in the diffracted beam, giving a magnified projection image. So far, the method has been applied with a time resolution of milliseconds to hours. In this work, the feasibility of DFXM at the picosecond time scale using an X-ray free-electron laser source and a pump–probe scheme is considered. Thermomechanical strain-wave simulations are combined with geometrical optics and wavefront propagation optics to simulate DFXM images of phonon dynamics in a diamond single crystal. Using the specifications of the XCS instrument at the Linac Coherent Light Source as an example results in simulated DFXM images clearly showing the propagation of a strain wave.

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Sidorova O. V., Aleshina L. A., and Fofanov A. D. "X-ray Study and Computer Simulation of the Structure of Amorphous-Crystalline Titanite." Physics of the Solid State 64, no. 2 (2022): 248. http://dx.doi.org/10.21883/pss.2022.02.53274.197.

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The structure of amorphous-crystalline titanite obtained by mechanical activation was studied by X-ray diffraction and simulation methods. The short-range order characteristics were calculated using Finbak-Warren's method. It was found that the coordination numbers of metal atoms decreased as the result of titanite grinding. The atomic configurations of short-range order of ground titanite were constructed by translation of titanite unit cell. The theoretical X-ray patterns were calculated using Debye's method and were compared with the experimental curves. The structure of ground titanite in the mill with centrifugal factor 40 g was described satisfactorily by the model of mechanical mixture of clusters containing 2016 atoms, disordered during the molecular dynamics with clusters containing 12096 atoms. The increase of grinding intensity led to the sharp decrease of sizes of small cluster. Keywords: amorphous-crystalline titanite, X-ray diffraction, computer simulation, mechanical activation, Debye's method.

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Yokhana, Viona S. K., Benedicta D. Arhatari, and Brian Abbey. "Materials Separation via the Matrix Method Employing Energy-Discriminating X-ray Detection." Applied Sciences 12, no. 6 (March 21, 2022): 3198. http://dx.doi.org/10.3390/app12063198.

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The majority of lab-based X-ray sources are polychromatic and are not easily tunable, which can make the 3D quantitative analysis of multi-component samples challenging. The lack of effective materials separation when using conventional X-ray tube sources has motivated the development of a number of potential solutions including the application of dual-energy X-ray computed tomography (CT) as well as the use of X-ray filters. Here, we demonstrate the simultaneous decomposition of two low-density materials via inversion of the linear attenuation matrices using data from the energy-discriminating PiXirad detector. A key application for this method is soft-tissue differentiation which is widely used in biological and medical imaging. We assess the effectiveness of this approach using both simulation and experiment noting that none of the materials investigated here incorporate any contrast enhancing agents. By exploiting the energy discriminating properties of the detector, narrow energy bands are created resulting in multiple quasi-monochromatic images being formed using a broadband polychromatic source. Optimization of the key parameters for materials separation is first demonstrated in simulation followed by experimental validation using a phantom test sample in 2D and a small-animal model in 3D.

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Duncumb, Peter, Ian R. Barkshire, and Peter J. Statham. "Improved X-ray Spectrum Simulation for Electron Microprobe Analysis." Microscopy and Microanalysis 7, no. 4 (July 2001): 341–55. http://dx.doi.org/10.1007/s10005-001-0010-6.

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AbstractThe accurate calculation of characteristic peak intensity is essential for interpreting X-ray spectra in electron microprobe analysis. Conventionally, the measured intensity from a standard of known composition is used as a reference to simplify the calculation. However, if no such standard is available, then all factors influencing X-ray generation and X-ray detection efficiency must be included. If the intensity and energy distribution of the background radiation can also be calculated, the investigator can simulate an entire spectrum from an assumed composition, gaining powerful benefits in setting up an experiment and in confirming the results. The study presented here demonstrates a fast method of spectrum simulation, suitable for energydispersive spectroscopy (EDS), and assesses the accuracy using 309 spectra from samples of known composition. These include K, L, and M lines from elements of atomic number 6–92, excited by beam energies in the range of 5–30 keV. The RMS error between 360 measured and calculated peak intensities was found to be 7.1%. Central to the method is the use of the ratio of peak intensity/total background intensity, which allows spectra to be compared from instruments of differing collection efficiency, thereby easing the collection of data over a wide range of conditions.

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Tamba, Tsubasa, Hirokazu Odaka, Aya Bamba, Hiroshi Murakami, Koji Mori, Kiyoshi Hayashida, Yukikatsu Terada, Tsunefumi Mizuno, and Masayoshi Nobukawa. "Simulation-based spectral analysis of X-ray CCD data affected by photon pile-up." Publications of the Astronomical Society of Japan 74, no. 2 (March 7, 2022): 364–83. http://dx.doi.org/10.1093/pasj/psab131.

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Abstract We have developed a simulation-based method of spectral analysis for pile-up-affected data of X-ray CCDs without any loss of photon statistics. As effects of the photon pile-up appear as complicated nonlinear detector responses, we employ a detailed simulation to calculate the important processes in an X-ray observation including physical interactions, detector signal generation, detector readout, and a series of data reduction processes. This simulation naturally reproduces X-ray-like and background-like events as results of X-ray photon merging in a single pixel or in a chunk of adjacent pixels, allowing us to construct a nonlinear spectral analysis framework that can treat pile-up-affected observation data. For validation, we have performed data analysis of Suzaku X-ray Imaging Spectrometer (XIS) observations using this framework with various parameters of the detector simulation, all of which are optimized for that instrument. We present three cases of different pile-up degrees: PKS 2155−304 (negligible pile-up), Aquila X-1 (moderate pile-up), and the Crab Nebula (strong pile-up); we show that the nonlinear analysis method produces results consistent with a conventional linear analysis for the negligible pile-up condition, and accurately corrects well-known pile-up effects such as spectral hardening and flux decrease for the pile-up cases. These corrected results are consistent with those obtained by a widely used core-exclusion method or by other observatories with much higher timing resolutions (without pile-up). Our framework is applicable to any types of CCDs used for X-ray astronomy, including future missions such as X-ray Imaging and Spectroscopy Mission (XRISM), by appropriate optimization of the simulation parameters.

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Jia, Chunjing. "A Wannier orbital based method for resonant inelastic x-ray scattering simulation." Journal of Physics: Conference Series 1290 (October 2019): 012014. http://dx.doi.org/10.1088/1742-6596/1290/1/012014.

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Liang, Hao, Yafeng Zhan, and Chaowei Duan. "A Bayesian Classifier for X-Ray Pulsars Recognition." International Journal of Aerospace Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/1746925.

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Recognition for X-ray pulsars is important for the problem of spacecraft’s attitude determination by X-ray Pulsar Navigation (XPNAV). By using the nonhomogeneous Poisson model of the received photons and the minimum recognition error criterion, a classifier based on the Bayesian theorem is proposed. For X-ray pulsars recognition with unknown Doppler frequency and initial phase, the features of every X-ray pulsar are extracted and the unknown parameters are estimated using the Maximum Likelihood (ML) method. Besides that, a method to recognize unknown X-ray pulsars or X-ray disturbances is proposed. Simulation results certificate the validity of the proposed Bayesian classifier.

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A. Yatsenko, Dmitriy, and Sergey V. Tsybulya. "Method of Simulation of Diffraction Pattern for Nanosize Crystalline Systems." Siberian Journal of Physics 3, no. 4 (December 1, 2008): 47–51. http://dx.doi.org/10.54362/1818-7919-2008-3-4-47-51.

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The original algorithm and the software for calculation of x-ray powder diffraction patterns from ensemble of nanocrystal particles are developed. Test calculations are carried out. Errors in definition of positions, integrated intensities and halfwidth of diffraction peaks are estimated.

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Li, Yao, Tong Su, Lizhi Sheng, Neng Xu, and Baosheng Zhao. "Simulation and experiment of X-ray communication in re-entry dusty plasma region." Modern Physics Letters B 34, no. 04 (December 20, 2019): 2050057. http://dx.doi.org/10.1142/s0217984920500578.

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Compared with the other wireless communication band, X-ray carrier has the merits of lower wavelength, higher frequency and photon energy, which could provide a novel method to solve the communication problems of re-entry blackout region. In this paper, transmission characteristics of X-ray carrier in the re-entry dusty plasma medium were analyzed first, simulation results indicate that dusty particles were more likely to impede the microwave signal than X-ray carrier. Then an alkali metal plasma source was designed to simulate the re-entry dusty plasma sheath for simplification. Transmission co-efficiency under different X-ray energy were tested, which pointed out that X-ray signal would obtain more than 79.4% transmission co-efficiency on condition of dynamic and dusty plasma medium. Finally, we give our proposal and potential capability of X-ray communication in the re-entry plasma condition.

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DOYAMA, MASAO, Y. KOGURE, T. NOZAKI, and Y. KATO. "TENSILE DEFORMATION OF COPPER SINGLE CRYSTALS BY SIMULATION USING X-RAY LANG METHOD AND MOLECULAR DYNAMICS." International Journal of Modern Physics B 16, no. 28n29 (November 20, 2002): 4431–35. http://dx.doi.org/10.1142/s0217979202015558.

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Simulations were performed to model the response of a copper rectangular parallelepiped single crystal with a notch to tensile deformation. Partial dislocations were created near the tip of the notch as we expected. It is hard to see where the dislocations were created by just looking at the displaced positions of atoms, but the creation of dislocations was easily observed by a simulation of X-ray Lang method. Before creation of dislocations, some indication was quite clearly shown. Laue patterns during tensile deformation were also simulated.

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He, T., R. P. Gardner, and K. Verghese. "NCSXRF: A General Geometry Monte Carlo Simulation Code for EDXRF Analysis." Advances in X-ray Analysis 35, B (1991): 727–36. http://dx.doi.org/10.1154/s037603080001291x.

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EDXRF analysis is conveniently split into two parts: (1) the determination of X-ray intensities and (2) the determination of elemental amounts from X-ray intensities. For the first, most EDXRF analysis has been done by some method of integrating the essentially Gaussian distribution of observed full energy pulse heights. This might be done, for example, by least-square fitting of Gaussian distributions superimposed on a straight line or a quadratic background. Recently more elaborate shapes of the energy peaks also have been considered (Kennedy, 1990). After the X-ray intensities have been determined, interelement effects between the analyte element and other elements must be corrected for in order to obtain the elemental amounts from X-ray intensities. This correction can be done either by an empirical correction procedure as in the influence coefficient method which requires measurements on a number of standard samples to determine the required coefficients, or by theoretical calculation as in the fundamental parameters method which does not require standard samples.

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Bionducci, M., F. Buffa, G. Licheri, and G. Navarra. "Testing the Reverse Monte Carlo Method Using Scattering Data from Amorphous Ni2Zr." Zeitschrift für Naturforschung A 47, no. 5 (May 1, 1992): 685–88. http://dx.doi.org/10.1515/zna-1992-0509.

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Abstract The reverse Monte Carlo simulation has been tested by modelling the partial distribution functions of amorphous Ni2Zr. Three runs of simulation involving experimental data from isotopic substitutions neutron scattering and X-ray anomalous scattering are presented

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Shim, Chi Hyun, Ki Moon Nam, Yong Woon Parc, and Dong Eon Kim. "Isolated terawatt sub-attosecond high-energy x-ray pulse generated by an x-ray free-electron laser." APL Photonics 7, no. 5 (May 1, 2022): 056105. http://dx.doi.org/10.1063/5.0067074.

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The endless quest for dynamics in natural phenomena has resulted in the generation and application of attosecond pulses to trace electron dynamics in atomic and molecular systems. The next challenge is to generate powerful pulses on the zeptosecond time scale, which is currently inaccessible. Through a simulation study, a new type of x-ray source that can generate an isolated terawatt sub-attosecond pulse at high-energy x rays by combining attosecond pulse technology with free-electron laser technology is proposed. The successful generation of a sub-attosecond pulse necessitates the consideration of nanometer-wide current-spikes, the sub-attosecond pulse amplification, and pulse duration and background noise control. The underlying interaction mechanism between a sub-attosecond pulse and a current-spike is closely investigated using the simulation results. The proposed method is expected to produce an isolated ∼700 zs pulse with a peak output of 2.9 TW at a photon energy of 247.5 keV.

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Demers, Hendrix, and Raynald Gauvin. "X-ray Microanalysis of a Coated Nonconductive Specimen: Monte Carlo Simulation." Microscopy and Microanalysis 10, no. 6 (December 2004): 776–82. http://dx.doi.org/10.1017/s1431927604040607.

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The microanalysis of nonconductive specimen in a scanning electron microscope is limited by charging effects. Using a charge density model for the electric field buildup in a nonconductive specimen irradiated by electrons, a Monte Carlo simulation method has been applied to alumina (Al2O3). The results show a change in the depth distribution for characteristic and bremsstrahlung X-ray, φ(ρz) curves, and ψ(ρz) curves (with absorption) for both elements' Kα lines. The influence of the electric field on the measured X-ray intensity is shown. The dependency of this influence by the three parameters, electron energy, X-ray energy, and charge density, is clarified.

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Kishimoto, Akihiko, Shinji Kuniyoshi, Naoto Saito, Takashi Soga, Kozo Mochiji, and Takeshi Kimura. "Minimization of X-Ray Mask Distortion by Two-Dimensional Finite Element Method Simulation." Japanese Journal of Applied Physics 29, Part 1, No. 10 (October 20, 1990): 2203–6. http://dx.doi.org/10.1143/jjap.29.2203.

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33

Carvalho, C. A. M., and Y. Epelboin. "Simulation of X-ray topographs: a new method to calculate the diffracted field." Acta Crystallographica Section A Foundations of Crystallography 49, no. 3 (May 1, 1993): 460–67. http://dx.doi.org/10.1107/s0108767392010717.

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34

Depaola, G. O., and F. Longo. "Measuring polarization in the X-ray range: New simulation method for gaseous detectors." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 566, no. 2 (October 2006): 590–97. http://dx.doi.org/10.1016/j.nima.2006.07.060.

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Liang, Kaichao, Li Zhang, and Yuxiang Xing. "Reciprocal-FDK reconstruction for x-ray diffraction computed tomography." Physics in Medicine & Biology 67, no. 9 (April 20, 2022): 095009. http://dx.doi.org/10.1088/1361-6560/ac5bf9.

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Abstract Objective. X-ray diffraction (XRD) technology uses x-ray small-angle scattering signal for material analysis, which is highly sensitive to material inter-molecular structure. To meet the high spatial resolution requirement in applications such as medical imaging, XRD computed tomography (XRDCT) has been proposed to provide XRD intensity with improved spatial resolution from point-wise XRD scan. In XRDCT, 2D spatial tomography corresponds to a 3D reconstruction problem with the third dimension being the XRD spectrum dimension, i.e. the momentum transfer dimension. Current works in the field have studied reconstruction methods for either angular-dispersive XRDCT or energy-dispersive XRDCT for small samples. The approximations used are only suitable for regions near the XRDCT iso-center. A new XRDCT reconstruction method is needed for more general imaging applications. Approach. We derive a new FDK-type reconstruction method (Reciprocal-FDK) for XRDCT without limitation on object size. By introducing a set of reciprocal variables, the XRDCT model is transformed into a classical cone-parallel CT model, which is an extension of a circular-trajectory cone-beam CT model, after which the FDK method is applied for XRDCT reconstruction. Main results. Both analytical simulation and Monte Carlo simulation experiments are conducted to validate the XRDCT reconstruction method. The results show that when compared to existing analytical reconstruction methods, there are improvements in the proposed Reciprocal-FDK method with regard to relative structure reconstruction and XRD pattern peak reconstruction. Since cone-parallel CT does not satisfy the data completeness condition, cone-angle effect affects the reconstruction accuracy of XRDCT. The property of cone-angle effect in XRDCT is also analyzed with ablation studies. Significance. We propose a general analytical reconstruction method for XRDCT without constraint on object size. Reciprocal-FDK provides a complete derivation and theoretical support for XRDCT reconstruction by analogy to the well-studied cone-parallel CT model. In addition, the intrinsic problem with the XRDCT data model and the corresponding reconstruction error are discussed for the first time.

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Condino, Sara, Giuseppe Turini, Virginia Mamone, Paolo Domenico Parchi, and Vincenzo Ferrari. "Hybrid Spine Simulator Prototype for X-ray Free Pedicle Screws Fixation Training." Applied Sciences 11, no. 3 (January 24, 2021): 1038. http://dx.doi.org/10.3390/app11031038.

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Simulation for surgical training is increasingly being considered a valuable addition to traditional teaching methods. 3D-printed physical simulators can be used for preoperative planning and rehearsal in spine surgery to improve surgical workflows and postoperative patient outcomes. This paper proposes an innovative strategy to build a hybrid simulation platform for training of pedicle screws fixation: the proposed method combines 3D-printed patient-specific spine models with augmented reality functionalities and virtual X-ray visualization, thus avoiding any exposure to harmful radiation during the simulation. Software functionalities are implemented by using a low-cost tracking strategy based on fiducial marker detection. Quantitative tests demonstrate the accuracy of the method to track the vertebral model and surgical tools, and to coherently visualize them in either the augmented reality or virtual fluoroscopic modalities. The obtained results encourage further research and clinical validation towards the use of the simulator as an effective tool for training in pedicle screws insertion in lumbar vertebrae.

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Gao, Kuo, Hong Yu, Tie Qiao Guo, Er Jun Pang, Tao Dong, and Zhi Wang Cheng. "The Insulation Sheath Detection Based on X-Ray." Applied Mechanics and Materials 696 (November 2014): 119–26. http://dx.doi.org/10.4028/www.scientific.net/amm.696.119.

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Because of its excellent electrical properties, the insulation sheath is widely used in outdoor power equipment terminal stop position. The performance of the insulation sheath will directly affect the normal operation of electrical equipment. For the insulation sheath detection rely mainly on traditional electrical insulation testing means. This article through using ANSYS finite element simulation software to simulate the hole type defects of the insulation sheath. Then combination of X-ray DR detection system with traditional electrical insulation testing method, testing of three insulation sheath, the test results are consistent with the simulation results. At the same time, this article illustrates the possibility and the reliability of X-ray DR detection system on the insulation sheath.

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Gao, Kuo, Hong Yu, Tie Qiao Guo, Er Jun Pang, Tao Dong, and Zhi Wang Cheng. "The Insulation Sheath Detection Based on X-Ray." Applied Mechanics and Materials 422 (September 2013): 62–69. http://dx.doi.org/10.4028/www.scientific.net/amm.422.62.

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Because of its excellent electrical properties, the insulation sheath is widely used in outdoor power equipment terminal stop position. The performance of the insulation sheath will directly affect the normal operation of electrical equipment. For the insulation sheath detection rely mainly on traditional electrical insulation testing means. This article through using ANSYS finite element simulation software to simulate the hole type defects of the insulation sheath. Then combination of X-ray DR detection system with traditional electrical insulation testing method, testing of three insulation sheath, the test results are consistent with the simulation results. At the same time, this article illustrates the possibility and the reliability of X-ray DR detection system on the insulation sheath.

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Zhang, Y. Y., M. X. Tang, Y. Cai, J. C. E, and S. N. Luo. "Deducing density and strength of nanocrystalline Ta and diamond under extreme conditions from X-ray diffraction." Journal of Synchrotron Radiation 26, no. 2 (January 21, 2019): 413–21. http://dx.doi.org/10.1107/s1600577518017216.

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In situ X-ray diffraction with advanced X-ray sources offers unique opportunities for investigating materials properties under extreme conditions such as shock-wave loading. Here, Singh's theory for deducing high-pressure density and strength from two-dimensional (2D) diffraction patterns is rigorously examined with large-scale molecular dynamics simulations of isothermal compression and shock-wave compression. Two representative solids are explored: nanocrystalline Ta and diamond. Analysis of simulated 2D X-ray diffraction patterns is compared against direct molecular dynamics simulation results. Singh's method is highly accurate for density measurement (within 1%) and reasonable for strength measurement (within 10%), and can be used for such measurements on nanocrystalline and polycrystalline solids under extreme conditions (e.g. in the megabar regime).

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Vetter, W. M., H. Tsuchida, I. Kamata, and M. Dudley. "Simulation of threading dislocation images in X-ray topographs of silicon carbide homo-epilayers." Journal of Applied Crystallography 38, no. 3 (May 13, 2005): 442–47. http://dx.doi.org/10.1107/s0021889805005819.

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Three types of dislocation are seen in homo-epilayers of SiC grown on 4H-SiC wafers with an 8° surface offcut: axial screw dislocations, basal plane dislocations propagated into the epilayer at an 8° inclination and threading edge dislocations. These types may be imaged by monochromatic synchrotron X-ray topography in the grazing-incidence reflection geometry using the 11\overline 28 reflection. Equations needed to apply the ray-tracing method of computer simulating X-ray topographic defect images in this experimental geometry were derived and used to simulate images of all three. Simulations for axial screw dislocations appear as white circles surrounded by narrow dark rings, and those for basal plane dislocations as linear white streaks, both consistent with experimental topographs. Simulations of the threading edge dislocations showed 4 µm wide white ovals with narrow arcs of dark contrast at their ends, inclined relative to the g vector of the topograph according to the sign of their Burgers vector. These images resembled the experimental topographs inasmuch as was possible at the maximum resolution of X-ray topographs.

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Zhang, Dapeng, Wei Zheng, Yidi Wang, and Lu Zhang. "X-Ray Pulsar Profile Recovery Based on Tracking-Differentiator." Mathematical Problems in Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/4238165.

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The profile recovery is an important work in X-ray pulsar-based navigation. It is a key step for the analysis on the pulsar signal’s characteristic and the computing of time of arrival (TOA). This paper makes an argument for an algorithm based on the tracking-differentiator (TD) to recover the profile from the low Signal-to-Noise Ratio (SNR) signals. In the method, a TD filter with cascade structure is designed which has very low phase delay and amplitude distortion. In the simulation experiment, two typical pulsars (PSR B0531+21 and PSR B1937+21) are used to verify the algorithm’s performance. The simulation results show that the method satisfies the application requirements in the aspects of SNR and profile fidelity. By processing the data collected by the Rossi X-Ray Timing Explorer (RXTE) satellite in space, similar results can also be achieved.

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Collonge, M., P. Busca, P. Fajardo, and M. Williams. "Monte Carlo simulations for XIDer, a novel digital integration X-ray detector for the next generation of synchrotron radiation sources." Journal of Instrumentation 17, no. 01 (January 1, 2022): C01037. http://dx.doi.org/10.1088/1748-0221/17/01/c01037.

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Abstract This work presents the first simulation results of the incremental digital integration readout, a charge-integrating front-end scheme with in-pixel digitisation and accumulation. This novel readout concept is at the core of the XIDer (X-ray Integrating Detector) project, which aims to design 2D pixelated X-ray detectors optimised for high energy scattering and diffraction applications for the next generation of synchrotron radiation sources such as the ESRF Extremely Brilliant Source (EBS). The digital integration readout and the XIDer detector open the possibilities for high-duty-cycle operation under very high photon flux, fast frame-rate and high dynamic range with single-photon sensitivity in the 30–100 keV energy range. The readout method allows for noise-free effective X-ray detection. The digital integration concept is currently under investigation to evaluate the impact of main critical design parameters to identify the strengths and weaknesses of the readout scheme and consequently to propose refinements in the final implementation. Simulations have been performed with a dedicated Monte Carlo simulation tool, X-DECIMO, a modular Python package designed to recreate the complete detection chain of X-ray detectors for synchrotron radiation experiments. Losses and non-linearities of the readout scheme are simulated and quantified. In addition to presenting simulation results for this novel readout scheme, this work underlines the potential of the approach and some of its limitations.

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Kshevetskii, S., P. Wojda, and V. Maximov. "A high-accuracy complex-phase method of simulating X-ray propagation through a multi-lens system." Journal of Synchrotron Radiation 23, no. 6 (October 10, 2016): 1305–14. http://dx.doi.org/10.1107/s1600577516013333.

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The propagation of X-ray waves through an optical system consisting of many X-ray refractive lenses is considered. For solving the problem for an electromagnetic wave, a finite-difference method is applied. The error of simulation is analytically estimated and investigated. It was found that a very detailed difference grid is required for reliable and accurate calculations of the propagation of X-ray waves through a multi-lens system. The reasons for using a very detailed difference grid are investigated. It was shown that the wave phase becomes a function, very quickly increasing with increasing distance from the optical axis, after the wave has passed through the multi-lens system. If the phase is a quickly increasing function of the coordinates perpendicular to the optical axis, then the electric field of the wave is a quickly oscillating function of these coordinates, and thus a very detailed difference grid becomes necessary to describe such a wavefield. To avoid this difficulty, an equation for the phase function is proposed as an alternative to the equation of the electric field. This allows reliable and accurate simulations to be carried out when using the multi-lens system. An equation for the phase function is derived and used for accurate simulations. The numerical error of the suggested method is estimated. It is shown that the equation for the phase function allows efficient simulations to be fulfilled for the multi-lens system.

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Vetter, William M., Hidekazu Tsuchida, Isaho Kamata, and Michael Dudley. "Simulation of Threading Edge Dislocation Images in X-Ray Topographs of Silicon Carbide Homo-Epilayers." Materials Science Forum 527-529 (October 2006): 411–14. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.411.

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Among the types of dislocation seen in homo-epilayers of SiC grown upon 4H-SiC wafers with an 8° surface offcut are basal plane dislocations propagated into the epilayer at an 8° inclination, and threading edge dislocations. These types may be imaged by monochromatic synchrotron x-ray topography in the grazing-incidence reflection geometry using the 11 2 8 reflection. Equations needed to apply the ray-tracing method of computer simulating x-ray topographic defect images in this experimental geometry were derived and used to simulate images of the threading edge dislocations. Simulations of the threading edge dislocations showed 4 μm wide white ovals with narrow arcs of dark contrast at their ends, inclined relative to the g-vector of the topograph according to the sign of their Burgers vector. These resembled the experimental topographs, inasmuch as was possible at the maximum resolution of x-ray topographs.

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Stanković, Srboljub J., R. D. Ilić, O. Ciraj-Bjelac, M. Kovačević, and David Davidović. "Characterization of Target Material for X-Ray Generator by Monte Carlo Method." Materials Science Forum 555 (September 2007): 137–40. http://dx.doi.org/10.4028/www.scientific.net/msf.555.137.

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The adequate choice of different target materials for X-ray generators is a very important subject of engineers’ practice and research. In the present work we analyze theoretically the transport of electrons through the anode material and the production of the corresponding bremsstrahlung radiation. In our analysis we simulate the particle transport with the help of the FOTELP code, which is based on the Monte Carlo simulation. Our main aim is to develop an efficient and handy method, which could be helpful in improving the design of the X-ray tube components and in reducing of the patient dose, while keeping the image quality. The obtained results are encouraging.

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Choi, Mina, Bahaa Ghammraoui, Andreu Badal, and Aldo Badano. "Monte Carlo X-ray transport simulation of small-angle X-ray scattering instruments using measured sample cross sections." Journal of Applied Crystallography 49, no. 1 (February 1, 2016): 188–94. http://dx.doi.org/10.1107/s1600576715023924.

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Small-angle X-ray scattering (SAXS) has recently been proposed as a novel noninvasivein vivomolecular imaging technique to characterize molecular interactions deep within the body using high-contrast probes. This article describes a detailed Monte Carlo X-ray transport simulation technique that utilizes user-provided cross sections to describe X-ray interaction in virtual samples and explore SAXS instrument design choices. The accuracy of the simulation code is validated with sample material cross sections derived from analytical models and empirical measurements of a homogeneous spherical gold nanoparticle (GNP) monomer, a dimer and heterogeneous mixtures of the two in aqueous solution. Analytical and measured scattering profiles from these samples were converted to cross sections using an absolute water standard. Our Monte Carlo estimates of the fraction of dimers from analytically derived and empirically derived cross sections are strongly correlated, with less than 1.5 and 16% error, respectively, to the expected concentration of monomer and dimer species. In addition, a variety of monoenergetic X-ray beams were simulated to investigate coherent scatteringversusradiation dose for a range of sample sizes. For GNP spheres in aqueous solution, the energy range that produces the most coherent scattering at the detector per deposited energy was between 31 and 49 keV for a sample thickness of 1 mm to 10 cm. The method described here for the detailed simulation of SAXS using measured and modeled cross sections will enable instrumentation optimization forin vivomolecular imaging applications.

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Sosa, C., V. Stoytschew, J. Leani, H. J. Sánchez, C. A. Pérez, and R. D. Perez. "Calibration Method for Confocal X-Ray Microanalysis with Polychromatic Excitation." Journal of Spectroscopy 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/368054.

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To apply the fundamental parameters method at the confocal setup the knowledge of the sensitivity of the spectrometer is required which depends on the characteristics of two X-ray lenses: one in the excitation channel and another in the detection channel. For the particular case of polychromatic excitation, the theory shows that the focalization properties of the excitation lens for all incident energies affect the X-ray fluorescence intensity. Therefore the traditional calibration method based on the measurement of standard samples becomes unstable since the number of required fitting parameters is too high. To reduce these parameters a previous characterization of the excitation lens by a simulation program was employed giving rise to a simplified confocal setup calibration. The developed calibration method was applied for a confocal spectrometer implemented in the Brazilian Synchrotron Radiation Source (LNLS) with white beam. The experimental parameters of the sensitivity were obtained from depth profile analysis of several pure thin films. The calibrated confocal setup was used to quantify reference standards in order to validate the calibration procedure. Our results for elemental concentrations show relative errors less than 15% for the quantitative analysis of a light matrix reference standard.

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Tao, Ya-Le, Zhen Jiao, Zheng-Tang Liu, Cheng-Lu Jiang, and Qi-Jun Liu. "Preparation of Niobium Aluminium Alloy Based on Shock Compression Method." Crystals 12, no. 3 (March 12, 2022): 381. http://dx.doi.org/10.3390/cryst12030381.

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A new method based on a light-gas gun has been proposed to synthesize Nb-Al alloys, and a recovery capsule has been investigated. The copper-coated sample is accessible after shock wave loading. In this paper, we successfully synthesize Nb-Al alloys, which are high-temperature structural materials. X-ray diffraction is employed to clarify the structural characteristics of compounds after impact, and the simulation of X-ray diffractions is employed to clarify the structure. In detail, tetragonal NbAl3 alloys certainly appeared in the recovery capsule; this alloy is considered to be best candidate.

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Wang, Dengwang, Yong Gao, Wei Chen, Jing Zhang, and Sheng Wang. "Equivalent Analysis of Thermo-Dynamic Blow-Off Impulse under X-ray Irradiation." Applied Sciences 11, no. 19 (September 23, 2021): 8853. http://dx.doi.org/10.3390/app11198853.

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X-ray thermodynamic effect is an important damage mode for spacecraft. Blow-off impulse as the main thermodynamic damage parameter has been widely studied by combining laboratory and numerical simulations. In this paper, most calculations and analyses have been carried out by using the self-developed software RAMA, including the equivalent calculation of blow-off impulse of monoenergetic and blackbody X-ray, and soft/hard blackbody X-ray irradiated at different incidence angles of LY-12 aluminium target. The results show that the characteristic mono-energetic X-ray can be exploited to simulate the blow-off impulse of the blackbody X-ray under certain conditions as a feasible equivalent method for the equal-flux and equal-impulse relations between mono-energetic and intense pulse blackbody of blow-off impulse. Moreover, the equivalent thermodynamic effect can be achieved between the point source radiation and parallel X-ray of X-ray. Furthermore, the cosine distribution of blow-off impulse is conducive to designing and calculating X-ray radiation load of hard aluminium corresponding to 1–5 keV blackbody spectrum. The mentioned results can be referenced for pulse X-ray simulation source and enhance the fidelity of the thermal-mechanical effect by electron beam. It is noteworthy that the study on the thermodynamic effects of intense pulsed X-ray is of high significance.

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Chen, Ming, Dimeng Xia, Dan Wang, Jingqi Han, and Zhu Liu. "An Analytical Method for Reducing Metal Artifacts in X-Ray CT Images." Mathematical Problems in Engineering 2019 (January 13, 2019): 1–7. http://dx.doi.org/10.1155/2019/2351878.

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Medical CT imaging often encounters metallic implants or some metal interventional therapy apparatus. These metallic objects can produce metal artifacts in reconstruction images, which severely degrade image quality. In this paper, we analyze the difference between polychromatic projection data and Radon transform data and develop an analytical method to reduce metal artifacts. Approximate features of metal artifacts can be obtained by a simplified energy spectrum function of x-ray beam. The developed method can reduce most artifacts, and preserve more original details. It does not require prior knowledge of x-ray energy spectrum and original projection data, avoiding iterative calculation and saving reconstruction time. Simulation experimental results show that the method can greatly remove metal artifacts.

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Journal articles on the topic 'X-ray simulation method'

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