Simulation of x-ray spectra generated by electron impact on solids

Acosta, E.; Llovet, Xavier; Coleoni, Enrique Andrés; Salvat, F.; Riveros, José A.

doi:10.1002/(sici)1097-4539(199903/04)28:2<121::aid-xrs305>3.0.co;2-a

Cited by 13 publications

(9 citation statements)

References 20 publications

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“…Remembering that electrons accelerated in the X‐ray tube do not constitute a perfect monochromatic beam and keeping in mind that no negligible considerations may be required to describe the interaction and attenuation along with corresponding secondary scattering effects due to the anode presence, it could be concluded that the obtained simulation results show an reasonable agreement with the simplified model based on relativistic electrodynamics. Although semi‐empirical models14, 25 and complex theoretical34–37 expressions may provide more suitable description of Bremsstrahlung angular distribution, it would require exhaustive theoretical considerations, which may be out of the present work scopes.…”

Section: Resultsmentioning

confidence: 99%

“…Remembering that electrons accelerated in the X-ray tube do not constitute a perfect monochromatic beam and keeping in mind that no negligible considerations may be required to describe the interaction and attenuation along with corresponding secondary scattering effects due to the anode presence, it could be concluded that the obtained simulation results show an reasonable agreement with the simplified model based on relativistic electrodynamics. Although semi-empirical models [14,25] and complex theoretical [34 -37] expressions may provide more suitable description of Bremsstrahlung angular distribution, it would require exhaustive theoretical considerations, which may be out of the present work scopes. Once the energy spectral composition and angular distribution are well characterized, it becomes straightforward to assess a twodimensional map characterizing the Bremsstrahlung emission with respect to energy composition and angular distribution simultaneously, which may constitute a suitable and convenient representation, as shown in Fig.…”

Section: X-ray Bremsstrahlung Spectra By Means Of the Monte Carlo Methodsmentioning

confidence: 99%

“…[17] On the other hand, Monte Carlo simulations have proved to be a very useful tool to obtain accurate description of the complete spectrum. [14,15,18] Since the first review articles on the use of Monte Carlo methods for radiation transport and successive applications, [19] where the principles of the Monte Carlo method were described, the number of publications regarding radiation transport particularly in the medical physics field using the simulation of the transport of radiation continues to increase. [20] With the rapid development of computer technology, the Monte Carlo technique, currently one of the most accurate methods for dose calculation is becoming even more practical for use in radiation transport applications.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, in the literature, X‐ray spectrum analytical models may be found13–15, successfully describing the continuum background, whereas characteristic peaks are usually somewhat harder to assess. Actually, interpolating methods, like XOP program and the XCOM16 toolkit, both based on spectral models using interpolating polynomials and experimental data extracted from measured conventional X‐ray tube spectra along with mass attenuation coefficients, provide suitable Bremsstrahlung description.…”

Section: Introductionmentioning

confidence: 99%

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X‐ray spectra by means of Monte Carlo simulations for imaging applications

Tirao¹,

Quintana²,

Malano³

et al. 2010

X-Ray Spectrometry

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X-ray tubes have a broad range of applications worldwide, including several techniques for atomic physics, like X-ray fluorescence, as well as for medical imaging, like computed tomography. The performances of X-ray imaging detectors have shown to be significantly sensitive to the incident beam spectrum. Therefore, an accurate knowledge of the X-ray beam becomes necessary for the emission source characterization and the whole imaging process comprehension. Direct measurements and suitable Monte Carlo simulations may be used to establish the X-ray spectra. Dedicated Monte Carlo simulation routines, based on the PENELOPE code, have been developed to determine the Bremsstrahlung X-ray spectra generated by conventional X-ray tubes. The simulated spectra have been validated by comparison with the corresponding experimental data showing an overall good agreement. The incorporation of a suitably designed virtual grid allowed to assess the angular distribution of Bremsstrahlung yield, showing a remarkable anisotropy. In addition, a dedicated program has been developed for virtual imaging, which enables to perform suitable X-ray absorption contrast images. Also, the developed program includes a user-friendly graphic interface to allow the upload of required input parameters, which include setup arrangement, beam characteristics, sample properties and image simulation parameters (spatial resolution, tracks per run, etc.). The software includes dedicated subroutines which handle the physical process from X-ray generation up to detector signal acquisition. The aim of the developed program is to perform virtual imaging by means of absorption contrast and using conventional X-ray sources, which may be a useful tool for the study the X-ray imaging techniques in several research fields as well as for educational purposes. The performed comparisons with experimental data have shown good agreement. The obtained results for X-ray imaging may constitute useful information for the comprehension and improvement of X-ray image quality, like absorption contrast optimization, detail visualization, definition and detectability.

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Section: Resultsmentioning

confidence: 99%

Section: X-ray Bremsstrahlung Spectra By Means Of the Monte Carlo Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

X‐ray spectra by means of Monte Carlo simulations for imaging applications

Tirao¹,

Quintana²,

Malano³

et al. 2010

X-Ray Spectrometry

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“…If the number of generated tracks is large enough, quantitative information on the transport process may be obtained by averaging over a statistically significant number of trajectories. In this work, the PENELOPE routine package (Salvat et al, 2009) has been chosen as it has proved to adequately describe EPMA experimental situations (Acosta et al, 1998;Salvat et al, 2006;Escuder et al, 2008Escuder et al, , 2010.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo Simulation of Characteristic Secondary Fluorescence in Electron Probe Microanalysis of Homogeneous Samples Using the Splitting Technique

Petaccia

Castellano

2015

Microsc Microanal

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Electron probe microanalysis (EPMA) is based on the comparison of characteristic intensities induced by monoenergetic electrons. When the electron beam ionizes inner atomic shells and these ionizations cause the emission of characteristic X-rays, secondary fluorescence can occur, originating from ionizations induced by X-ray photons produced by the primary electron interactions. As detectors are unable to distinguish the origin of these characteristic X-rays, Monte Carlo simulation of radiation transport becomes a determinant tool in the study of this fluorescence enhancement. In this work, characteristic secondary fluorescence enhancement in EPMA has been studied by using the splitting routines offered by PENELOPE 2008 as a variance reduction alternative. This approach is controlled by a single parameter NSPLIT, which represents the desired number of X-ray photon replicas. The dependence of the uncertainties associated with secondary intensities on NSPLIT was studied as a function of the accelerating voltage and the sample composition in a simple binary alloy in which this effect becomes relevant. The achieved efficiencies for the simulated secondary intensities bear a remarkable improvement when increasing the NSPLIT parameter; although in most cases an NSPLIT value of 100 is sufficient, some less likely enhancements may require stronger splitting in order to increase the efficiency associated with the simulation of secondary intensities.

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Electron transport in solids for quantitative surface analysis

Werner

2001

Surface & Interface Analysis

315

276

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The influence of electron transport on the signal generation process in electron beam techniques is reviewed. A survey of the fundamental physical quantities for the electron-solid interaction is presented and sources for these quantities in the literature as well as semi-empirical formulae are given. The theoretical approaches used to describe multiple scattering in solids are outlined. These include the partial intensity approach and the continuous slowing down approximation to describe multiple energy losses and the transport approximation to tackle multiple deflections. A detailed description of the Monte Carlo technique is presented because this constitutes an effective means to study transport processes. The different theoretical approaches are illustrated in a survey of applications. These include: quantitative description of the surface sensitivity in Auger and photoelectron spectroscopy; line shape analysis of electron spectra; extracting information on the compositional depth profile from the combined energy/angular distribution in an electron spectrum; quasi-elastic electron reflection; inelastic electron backscattering; depth distribution of production of x-rays caused by electron bombardment; and the surface sensitivity in total electron yield electron spectroscopy. These applications demonstrate that the outlined approaches have a broad field of application, not only for electrons with energies ranging from thermal to the relativistic energy range, but also for other microbeam analysis techniques.

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Simulation of x-ray spectra generated by electron impact on solids

Cited by 13 publications

References 20 publications

X‐ray spectra by means of Monte Carlo simulations for imaging applications

X‐ray spectra by means of Monte Carlo simulations for imaging applications

Monte Carlo Simulation of Characteristic Secondary Fluorescence in Electron Probe Microanalysis of Homogeneous Samples Using the Splitting Technique

Electron transport in solids for quantitative surface analysis

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