Antonio Leyva Fabelo - Academia.edu (original) (raw)

Papers by Antonio Leyva Fabelo

Research paper thumbnail of Efectos de la radiacion gamma del cobalto - 60 en los superconductores de altas temperaturas

Research paper thumbnail of Study of a GaAs:Cr-based Timepix detector using synchrotron facility

Journal of Instrumentation, Nov 10, 2017

High resistivity gallium arsenide compensated by chromium fabricated by Tomsk State University ha... more High resistivity gallium arsenide compensated by chromium fabricated by Tomsk State University has demonstrated a good suitability as a sensor material for hybrid pixel detectors used in X-ray imaging systems with photon energies up to 60 keV. The material is available with a thickness up to 1 mm and due to its Z number a high absorption efficiency in this energy region is provided. However, the performance of thick GaAs:Cr-based detectors in spectroscopic applications is limited by readout electronics with relatively small pixels due to the charge sharing effect. In this paper, we present the experimental investigation of the charge sharing effect contribution in the GaAs:Cr-based Timepix detector. By means of scanning the detector with a pencil photon beam generated by the synchrotron facility, the geometrical mapping of pixel sensitivity is obtained, as well as the energy resolution of a single pixel. The experimental results are supported by numerical simulations. The observed limitation of the GaAs:Cr-based Timepix detector for the high flux X-ray imaging is discussed.

Research paper thumbnail of Estudio del daño radiacional en detectores matriciales de CZT expuestos a los rayos gamma

DOAJ (DOAJ: Directory of Open Access Journals), Jul 1, 2008

Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la b... more Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la bahía de La Habana, Cuba. Se reportaron las concentraciones de 23 elementos (metales pesados y trazas), reportándose, por primera vez un grupo importante de elementos tierras raras (La, Ce, Nd, Sm, Eu, Tb, Yb y Lu). La normalización de los resultados a un metal de referencia demostró la presencia antropogénica de Sb, Ba, As, Cr y Zn producto de la descarga de residuales domésticos e industriales.

Research paper thumbnail of Characterization of GaAs:Cr-based Timepix detector using synchrotron radiation and charged particles

Journal of Instrumentation, Dec 23, 2016

The interest in the use of high resistivity gallium arsenide compensated by chromium (GaAs:Cr) fo... more The interest in the use of high resistivity gallium arsenide compensated by chromium (GaAs:Cr) for photon detection has been growing steadily due to its numerous advantages over silicon. At the same time, the prospects of this material as a sensor for pixel detectors in nuclear and high energy physics are much less studied. In this paper we report the results of characterization of the Timepix detectors hybridized with GaAs:Cr sensors of various thickness using synchrotron radiation and various charged particles, including alphas and heavy ions. The energy and spatial resolution have been determined. Interesting features of GaAs:Cr specific to the detector response to an extremely dense energy deposit by heavy ions have been observed for the first time. The long-term stability of the detector has been evaluated based on the measurements performed over one year. Possible limitation of GaAs:Cr as a sensor for high flux X-ray imaging is discussed.

Research paper thumbnail of Response of timepix detector with GaAs:Cr and Si sensor to heavy ions

Physics of Particles and Nuclei Letters, May 1, 2016

The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been s... more The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been studied at the cyclotron U-400M of the JINR Flerov Laboratory of Nuclear Reaction. Sensors produced from gallium arsenide compensated by chromium and from silicon are used for these measurements. While in Timepix detector with Si sensor the well-known so-called "volcano effect" observed, in Timepix detector with GaAs:Cr sensor such effect was completely absent. In the work the behavior of the Timepix detector with GaAs:Cr sensor under irradiation with heavy ions is described in comparison with the detector based on Si sensor. Also the possible reason for absence of "volcano" effect in GaAs:Cr detector is proposed.

Research paper thumbnail of Mathematical modelling of photon transport for the evaluation and optimization of an X-ray system for cultural heritage studies

Research paper thumbnail of Response of timepix detector with GaAs:Cr and Si sensor to heavy ions

Physics of Particles and Nuclei Letters, 2016

The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been s... more The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been studied at the cyclotron U-400M of the JINR Flerov Laboratory of Nuclear Reaction. Sensors produced from gallium arsenide compensated by chromium and from silicon are used for these measurements. While in Timepix detector with Si sensor the well-known so-called "volcano effect" observed, in Timepix detector with GaAs:Cr sensor such effect was completely absent. In the work the behavior of the Timepix detector with GaAs:Cr sensor under irradiation with heavy ions is described in comparison with the detector based on Si sensor. Also the possible reason for absence of "volcano" effect in GaAs:Cr detector is proposed.

Research paper thumbnail of Influence of hardness on the beta backscattering from carbon steels

Journal of Radioanalytical and Nuclear Chemistry, 1998

This paper shows the influence of hardness on the beta backscattering coefficient from heat treat... more This paper shows the influence of hardness on the beta backscattering coefficient from heat treated and plastic deformed carbon steel specimens. The observed effect cannot be explained as a change in the chemical composition of the sample (or effective atomic number). In order to explain the observed dependencies, it is necessary to take into account the structural defect and morphological

Research paper thumbnail of Simulación por Monte Carlo del transporte de las radiaciones en detectores dearseniuro de galio compensado con cromo

Nucleus, 2019

Some results obtained with the use of Monte Carlo mathematical simulation of radiation transport ... more Some results obtained with the use of Monte Carlo mathematical simulation of radiation transport in Timepix hybrid detectors based on chromium compensated gallium arsenide are presented in this contribution. The MCNPX, GEANT4, SRIM and MCCM code systems were used for this purpose. The in-depth profiles of the deposited energy by the incident photons within the sensor active volume, the shapes and dimensions of the generated charge carriers clouds for different incident energies and specific geometrical conditions were obtained and presented. The 22 Ne ions ranges in the target material for two different energies and the contributions of each energy loss channel were also determined. Finally, for a selected detector irradiated with photons of different energies, the displacement cross sections for each chemical element in the active material, as well as the number of displacements per atoms produced for each atomic species were calculated.

Research paper thumbnail of Study by Raman Spectroscopy of the Induced Radiation Damage in GaAs:Cr Exposed to 20 MeV Electron Beam

Revista Cubana de Física, Jul 14, 2021

Research paper thumbnail of Numeric Simulation of a new magnetic anisotropy sensor

Ingeniería Mecánica, Aug 1, 2013

Research paper thumbnail of Radiography imaging by 64/128 microstrip crystalline detector at different X-ray energies

Nucleus, 2006

This paper summarizes some results obtained in the study of position sensitive detectors develope... more This paper summarizes some results obtained in the study of position sensitive detectors developed for experiments of high energies physics with the objective of evaluating its possible application to obtain X-ray digital images. A crystalline silicon microstrip detector with 64/128 channels coupled to two RX64 chips was used to obtain radiographic images of different objects. The more relevant figures for spectrometry applications were measured and reported. Two-dimensional images were obtained by scanning the object with a collimated beam using different source-target-detector positioning and three sources of X-rays (6.4, 8.04 and 22.16 keV). The counts acquired by each strip correspond to a particular collimator position during the scan, thus serving to reconstruct the image of the exposed to X-ray object and to reveal its internal structure. The preliminary results obtained using in-house made mammography phantoms allow to infer that such kind of detectors could be successfully ...

Research paper thumbnail of Distribución de las vacancias generadas por la radiación gamma en los superconductores de YBCO

Research paper thumbnail of Imagenología radiográfica con detectores cristalinos de microbandas 64/128 y rayos X de diferentes energías

Nucleus, 2006

This paper summarizes some results obtained in the study of position sensitive detectors develope... more This paper summarizes some results obtained in the study of position sensitive detectors developed for experiments of high energies physics with the objective of evaluating its possible application to obtain X-ray digital images. A crystalline silicon microstrip detector with 64/128 channels coupled to two RX64 chips was used to obtain radiographic images of different objects. The more relevant figures for spectrometry applications were measured and reported. Two-dimensional images were obtained by scanning the object with a collimated beam using different source-target-detector positioning and three sources of X-rays (6.4, 8.04 and 22.16 keV). The counts acquired by each strip correspond to a particular collimator position during the scan, thus serving to reconstruct the image of the exposed to X-ray object and to reveal its internal structure. The preliminary results obtained using in-house made mammography phantoms allow to infer that such kind of detectors could be successfully ...

Research paper thumbnail of Estudio del efecto de compartición de cargas y la resolución energética del detector híbrido Timepix de arseniuro de galio compensado con cromo

Nucleus, 2019

Among the latest ionizing radiation detectors, those based on chromium compensated gallium arseni... more Among the latest ionizing radiation detectors, those based on chromium compensated gallium arsenide (GaAs:Cr) are ones of the most competitive for many applications due to their high Z and strong resistance to radiation damage. They have been used in high energy physics research, medical visualization and spatial technologies, geological prospecting, among other advanced fields. The object of this work is a 900 µm GaAs:Cr detector with Timepix readout technology. Some detector characteristics for three experimental conditions were measured and studied by using the X-rays from a synchrotron and an X-ray tube provided with different materials for obtaining the corresponding fluorescence photons. A complex function was used to decompose the differential spectra into the most important contributions involved. As an additional tool for the research, the mathematical modeling of the mobility of charge carriers generated by radiation within the active volume of the detector was used. The r...

Research paper thumbnail of Estudio del daño radiacional en detectores matriciales de CZT expuestos a los rayos gamma

Nucleus, 2009

Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la b... more Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la bahía de La Habana, Cuba. Se reportaron las concentraciones de 23 elementos (metales pesados y trazas), reportándose, por primera vez un grupo importante de elementos tierras raras (La, Ce, Nd, Sm, Eu, Tb, Yb y Lu). La normalización de los resultados a un metal de referencia demostró la presencia antropogénica de Sb, Ba, As, Cr y Zn producto de la descarga de residuales domésticos e industriales.

Research paper thumbnail of Electron and positron contributions to the displacement per atom profile in bulk multi-walled carbon nanotube material irradiated with gamma rays

Nucleus, 2013

Aporte de electrones y positrones al perfil de desplazamientos atómicos en materiales masivos de ... more Aporte de electrones y positrones al perfil de desplazamientos atómicos en materiales masivos de nanotubos de carbono de paredes múltiples irradiados con rayos gamma Resumen

Research paper thumbnail of Cálculo de la sección transversal de desplazamiento y la distribución de los dpa en detectores semiconductores de silicio amorfo hidrogenado en aplicaciones de imagenología digital médica

Nucleus, 2007

ABSTRACT In present paper the dependence of the displacement cross sections of the different spec... more ABSTRACT In present paper the dependence of the displacement cross sections of the different species of atoms in the a-Si:H structure, with the energy of the secondary electrons generated by the X-rays of the typical energies using in medical imaging applications, was calculated using the Mott-McKinley-Feshbach approach. It was verified that for electron energies higher than 1.52 keV it is possible the occurrence of hydrogen atoms displacements, while for the silicon atoms the threshold energy is 126 keV. These results were compared with those obtained for similar detectors but developed with crystalline silicon. With the use of the mathematical simulation of the radiation transport in the matter, the energy spectrum of the secondary electrons was calculated in order to estimate the number of atomic displacements, which take place in the semiconducting amorphous device in working regime. The spatial distribution of the dpa in the detectors volume, as well as its behavior with the depth in the work region are presented and discussed in the text.

Research paper thumbnail of Simulación y evaluación de la técnica de sustracción del borde de absorción en un sistema radiográfico espectrométrico destinado al estudio del patrimonio cultural

Nucleus, 2011

In this work the mathematical simulation of photon transport in the matter was used to evaluate t... more In this work the mathematical simulation of photon transport in the matter was used to evaluate the potentials of a new energy-resolved X-ray radiography system. The system is intended for investigations of cultural heritage object, mainly painting. The radiographic system uses polychromatic radiation from an X-ray tube and measures the spectrum transmitted through the object with an energy-dispersive X-ray detector on a pixel-by-pixel basis. Manipulation of the data-set obtained allows constructing images with enhanced contrast for certain elements. Here the use of the absorption edge subtraction technique was emphasized. The simulated results were in good agreement with the experimental data.

Research paper thumbnail of Estudio de la eficiencia cuántica de un detector de microbandas de silicio mediante la modelación matemática

Nucleus, 2011

The paper shows the results from the application of mathematical simulation to study the quantum ... more The paper shows the results from the application of mathematical simulation to study the quantum efficiency of a microstrips crystalline silicon detector, intended for medical imaging and the development of other applications such as authentication and dating of cultural heritage. The effects on the quantum efficiency of some parameters of the system, such as the detector-source geometry, X rays energy and detector dead zone thickness, were evaluated. The simulation results were compared with the theoretical prediction and experimental available data, resulting in a proper correspondence. It was concluded that the use of frontal confi guration for incident energies lower than 17 keV is more effi cient, however the use of the edge-on configuration for applications requiring the detection of energy above this value is recommended. It was also found that the reduction of the detector dead zone led to a considerable increase in quantum efficiency for any energy value in the interval fro...

Research paper thumbnail of Efectos de la radiacion gamma del cobalto - 60 en los superconductores de altas temperaturas

Research paper thumbnail of Study of a GaAs:Cr-based Timepix detector using synchrotron facility

Journal of Instrumentation, Nov 10, 2017

High resistivity gallium arsenide compensated by chromium fabricated by Tomsk State University ha... more High resistivity gallium arsenide compensated by chromium fabricated by Tomsk State University has demonstrated a good suitability as a sensor material for hybrid pixel detectors used in X-ray imaging systems with photon energies up to 60 keV. The material is available with a thickness up to 1 mm and due to its Z number a high absorption efficiency in this energy region is provided. However, the performance of thick GaAs:Cr-based detectors in spectroscopic applications is limited by readout electronics with relatively small pixels due to the charge sharing effect. In this paper, we present the experimental investigation of the charge sharing effect contribution in the GaAs:Cr-based Timepix detector. By means of scanning the detector with a pencil photon beam generated by the synchrotron facility, the geometrical mapping of pixel sensitivity is obtained, as well as the energy resolution of a single pixel. The experimental results are supported by numerical simulations. The observed limitation of the GaAs:Cr-based Timepix detector for the high flux X-ray imaging is discussed.

Research paper thumbnail of Estudio del daño radiacional en detectores matriciales de CZT expuestos a los rayos gamma

DOAJ (DOAJ: Directory of Open Access Journals), Jul 1, 2008

Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la b... more Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la bahía de La Habana, Cuba. Se reportaron las concentraciones de 23 elementos (metales pesados y trazas), reportándose, por primera vez un grupo importante de elementos tierras raras (La, Ce, Nd, Sm, Eu, Tb, Yb y Lu). La normalización de los resultados a un metal de referencia demostró la presencia antropogénica de Sb, Ba, As, Cr y Zn producto de la descarga de residuales domésticos e industriales.

Research paper thumbnail of Characterization of GaAs:Cr-based Timepix detector using synchrotron radiation and charged particles

Journal of Instrumentation, Dec 23, 2016

The interest in the use of high resistivity gallium arsenide compensated by chromium (GaAs:Cr) fo... more The interest in the use of high resistivity gallium arsenide compensated by chromium (GaAs:Cr) for photon detection has been growing steadily due to its numerous advantages over silicon. At the same time, the prospects of this material as a sensor for pixel detectors in nuclear and high energy physics are much less studied. In this paper we report the results of characterization of the Timepix detectors hybridized with GaAs:Cr sensors of various thickness using synchrotron radiation and various charged particles, including alphas and heavy ions. The energy and spatial resolution have been determined. Interesting features of GaAs:Cr specific to the detector response to an extremely dense energy deposit by heavy ions have been observed for the first time. The long-term stability of the detector has been evaluated based on the measurements performed over one year. Possible limitation of GaAs:Cr as a sensor for high flux X-ray imaging is discussed.

Research paper thumbnail of Response of timepix detector with GaAs:Cr and Si sensor to heavy ions

Physics of Particles and Nuclei Letters, May 1, 2016

The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been s... more The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been studied at the cyclotron U-400M of the JINR Flerov Laboratory of Nuclear Reaction. Sensors produced from gallium arsenide compensated by chromium and from silicon are used for these measurements. While in Timepix detector with Si sensor the well-known so-called "volcano effect" observed, in Timepix detector with GaAs:Cr sensor such effect was completely absent. In the work the behavior of the Timepix detector with GaAs:Cr sensor under irradiation with heavy ions is described in comparison with the detector based on Si sensor. Also the possible reason for absence of "volcano" effect in GaAs:Cr detector is proposed.

Research paper thumbnail of Mathematical modelling of photon transport for the evaluation and optimization of an X-ray system for cultural heritage studies

Research paper thumbnail of Response of timepix detector with GaAs:Cr and Si sensor to heavy ions

Physics of Particles and Nuclei Letters, 2016

The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been s... more The response of the Timepix detector to neon ions with kinetic energy 77 and 158.4 MeV has been studied at the cyclotron U-400M of the JINR Flerov Laboratory of Nuclear Reaction. Sensors produced from gallium arsenide compensated by chromium and from silicon are used for these measurements. While in Timepix detector with Si sensor the well-known so-called "volcano effect" observed, in Timepix detector with GaAs:Cr sensor such effect was completely absent. In the work the behavior of the Timepix detector with GaAs:Cr sensor under irradiation with heavy ions is described in comparison with the detector based on Si sensor. Also the possible reason for absence of "volcano" effect in GaAs:Cr detector is proposed.

Research paper thumbnail of Influence of hardness on the beta backscattering from carbon steels

Journal of Radioanalytical and Nuclear Chemistry, 1998

This paper shows the influence of hardness on the beta backscattering coefficient from heat treat... more This paper shows the influence of hardness on the beta backscattering coefficient from heat treated and plastic deformed carbon steel specimens. The observed effect cannot be explained as a change in the chemical composition of the sample (or effective atomic number). In order to explain the observed dependencies, it is necessary to take into account the structural defect and morphological

Research paper thumbnail of Simulación por Monte Carlo del transporte de las radiaciones en detectores dearseniuro de galio compensado con cromo

Nucleus, 2019

Some results obtained with the use of Monte Carlo mathematical simulation of radiation transport ... more Some results obtained with the use of Monte Carlo mathematical simulation of radiation transport in Timepix hybrid detectors based on chromium compensated gallium arsenide are presented in this contribution. The MCNPX, GEANT4, SRIM and MCCM code systems were used for this purpose. The in-depth profiles of the deposited energy by the incident photons within the sensor active volume, the shapes and dimensions of the generated charge carriers clouds for different incident energies and specific geometrical conditions were obtained and presented. The 22 Ne ions ranges in the target material for two different energies and the contributions of each energy loss channel were also determined. Finally, for a selected detector irradiated with photons of different energies, the displacement cross sections for each chemical element in the active material, as well as the number of displacements per atoms produced for each atomic species were calculated.

Research paper thumbnail of Study by Raman Spectroscopy of the Induced Radiation Damage in GaAs:Cr Exposed to 20 MeV Electron Beam

Revista Cubana de Física, Jul 14, 2021

Research paper thumbnail of Numeric Simulation of a new magnetic anisotropy sensor

Ingeniería Mecánica, Aug 1, 2013

Research paper thumbnail of Radiography imaging by 64/128 microstrip crystalline detector at different X-ray energies

Nucleus, 2006

This paper summarizes some results obtained in the study of position sensitive detectors develope... more This paper summarizes some results obtained in the study of position sensitive detectors developed for experiments of high energies physics with the objective of evaluating its possible application to obtain X-ray digital images. A crystalline silicon microstrip detector with 64/128 channels coupled to two RX64 chips was used to obtain radiographic images of different objects. The more relevant figures for spectrometry applications were measured and reported. Two-dimensional images were obtained by scanning the object with a collimated beam using different source-target-detector positioning and three sources of X-rays (6.4, 8.04 and 22.16 keV). The counts acquired by each strip correspond to a particular collimator position during the scan, thus serving to reconstruct the image of the exposed to X-ray object and to reveal its internal structure. The preliminary results obtained using in-house made mammography phantoms allow to infer that such kind of detectors could be successfully ...

Research paper thumbnail of Distribución de las vacancias generadas por la radiación gamma en los superconductores de YBCO

Research paper thumbnail of Imagenología radiográfica con detectores cristalinos de microbandas 64/128 y rayos X de diferentes energías

Nucleus, 2006

This paper summarizes some results obtained in the study of position sensitive detectors develope... more This paper summarizes some results obtained in the study of position sensitive detectors developed for experiments of high energies physics with the objective of evaluating its possible application to obtain X-ray digital images. A crystalline silicon microstrip detector with 64/128 channels coupled to two RX64 chips was used to obtain radiographic images of different objects. The more relevant figures for spectrometry applications were measured and reported. Two-dimensional images were obtained by scanning the object with a collimated beam using different source-target-detector positioning and three sources of X-rays (6.4, 8.04 and 22.16 keV). The counts acquired by each strip correspond to a particular collimator position during the scan, thus serving to reconstruct the image of the exposed to X-ray object and to reveal its internal structure. The preliminary results obtained using in-house made mammography phantoms allow to infer that such kind of detectors could be successfully ...

Research paper thumbnail of Estudio del efecto de compartición de cargas y la resolución energética del detector híbrido Timepix de arseniuro de galio compensado con cromo

Nucleus, 2019

Among the latest ionizing radiation detectors, those based on chromium compensated gallium arseni... more Among the latest ionizing radiation detectors, those based on chromium compensated gallium arsenide (GaAs:Cr) are ones of the most competitive for many applications due to their high Z and strong resistance to radiation damage. They have been used in high energy physics research, medical visualization and spatial technologies, geological prospecting, among other advanced fields. The object of this work is a 900 µm GaAs:Cr detector with Timepix readout technology. Some detector characteristics for three experimental conditions were measured and studied by using the X-rays from a synchrotron and an X-ray tube provided with different materials for obtaining the corresponding fluorescence photons. A complex function was used to decompose the differential spectra into the most important contributions involved. As an additional tool for the research, the mathematical modeling of the mobility of charge carriers generated by radiation within the active volume of the detector was used. The r...

Research paper thumbnail of Estudio del daño radiacional en detectores matriciales de CZT expuestos a los rayos gamma

Nucleus, 2009

Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la b... more Se realizó el análisis por activación neutrónica instrumental de sedimentos superficiales de la bahía de La Habana, Cuba. Se reportaron las concentraciones de 23 elementos (metales pesados y trazas), reportándose, por primera vez un grupo importante de elementos tierras raras (La, Ce, Nd, Sm, Eu, Tb, Yb y Lu). La normalización de los resultados a un metal de referencia demostró la presencia antropogénica de Sb, Ba, As, Cr y Zn producto de la descarga de residuales domésticos e industriales.

Research paper thumbnail of Electron and positron contributions to the displacement per atom profile in bulk multi-walled carbon nanotube material irradiated with gamma rays

Nucleus, 2013

Aporte de electrones y positrones al perfil de desplazamientos atómicos en materiales masivos de ... more Aporte de electrones y positrones al perfil de desplazamientos atómicos en materiales masivos de nanotubos de carbono de paredes múltiples irradiados con rayos gamma Resumen

Research paper thumbnail of Cálculo de la sección transversal de desplazamiento y la distribución de los dpa en detectores semiconductores de silicio amorfo hidrogenado en aplicaciones de imagenología digital médica

Nucleus, 2007

ABSTRACT In present paper the dependence of the displacement cross sections of the different spec... more ABSTRACT In present paper the dependence of the displacement cross sections of the different species of atoms in the a-Si:H structure, with the energy of the secondary electrons generated by the X-rays of the typical energies using in medical imaging applications, was calculated using the Mott-McKinley-Feshbach approach. It was verified that for electron energies higher than 1.52 keV it is possible the occurrence of hydrogen atoms displacements, while for the silicon atoms the threshold energy is 126 keV. These results were compared with those obtained for similar detectors but developed with crystalline silicon. With the use of the mathematical simulation of the radiation transport in the matter, the energy spectrum of the secondary electrons was calculated in order to estimate the number of atomic displacements, which take place in the semiconducting amorphous device in working regime. The spatial distribution of the dpa in the detectors volume, as well as its behavior with the depth in the work region are presented and discussed in the text.

Research paper thumbnail of Simulación y evaluación de la técnica de sustracción del borde de absorción en un sistema radiográfico espectrométrico destinado al estudio del patrimonio cultural

Nucleus, 2011

In this work the mathematical simulation of photon transport in the matter was used to evaluate t... more In this work the mathematical simulation of photon transport in the matter was used to evaluate the potentials of a new energy-resolved X-ray radiography system. The system is intended for investigations of cultural heritage object, mainly painting. The radiographic system uses polychromatic radiation from an X-ray tube and measures the spectrum transmitted through the object with an energy-dispersive X-ray detector on a pixel-by-pixel basis. Manipulation of the data-set obtained allows constructing images with enhanced contrast for certain elements. Here the use of the absorption edge subtraction technique was emphasized. The simulated results were in good agreement with the experimental data.

Research paper thumbnail of Estudio de la eficiencia cuántica de un detector de microbandas de silicio mediante la modelación matemática

Nucleus, 2011

The paper shows the results from the application of mathematical simulation to study the quantum ... more The paper shows the results from the application of mathematical simulation to study the quantum efficiency of a microstrips crystalline silicon detector, intended for medical imaging and the development of other applications such as authentication and dating of cultural heritage. The effects on the quantum efficiency of some parameters of the system, such as the detector-source geometry, X rays energy and detector dead zone thickness, were evaluated. The simulation results were compared with the theoretical prediction and experimental available data, resulting in a proper correspondence. It was concluded that the use of frontal confi guration for incident energies lower than 17 keV is more effi cient, however the use of the edge-on configuration for applications requiring the detection of energy above this value is recommended. It was also found that the reduction of the detector dead zone led to a considerable increase in quantum efficiency for any energy value in the interval fro...