Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit
Abstract. Imaging via ʸ backscattering techniques are suitable for non destructive and non invasive methods to determine the amount and distribution of matter in objects, and these are very advantageous techniques when the access to both sides of the sample, unlike in the transmission case, is not p...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2014 |
| País: | Colombia |
| Institución: | Universidad Nacional de Colombia |
| Repositorio: | Repositorio UN |
| Idioma: | español |
| OAI Identifier: | oai:repositorio.unal.edu.co:unal/75222 |
| Acceso en línea: | https://repositorio.unal.edu.co/handle/unal/75222 http://bdigital.unal.edu.co/39740/ |
| Access Level: | acceso abierto |
| Palabra clave: | 51 Matemáticas / Mathematics 53 Física / Physics 62 Ingeniería y operaciones afines / Engineering ʸ-backscattering Compton camera One-side imaging Geant4 Retrodisersión ʸ Imagenología por un costado Cámara compton |
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| dc.title.none.fl_str_mv |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| title |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| spellingShingle |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit Flechas García, David Camilo 51 Matemáticas / Mathematics 53 Física / Physics 62 Ingeniería y operaciones afines / Engineering ʸ-backscattering Compton camera One-side imaging Geant4 Retrodisersión ʸ Imagenología por un costado Cámara compton |
| title_short |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| title_full |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| title_fullStr |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| title_full_unstemmed |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| title_sort |
Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit |
| dc.creator.none.fl_str_mv |
Flechas García, David Camilo |
| author |
Flechas García, David Camilo |
| author_facet |
Flechas García, David Camilo |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Cristancho Mejía, Luis Fernando |
| dc.subject.none.fl_str_mv |
51 Matemáticas / Mathematics 53 Física / Physics 62 Ingeniería y operaciones afines / Engineering ʸ-backscattering Compton camera One-side imaging Geant4 Retrodisersión ʸ Imagenología por un costado Cámara compton |
| topic |
51 Matemáticas / Mathematics 53 Física / Physics 62 Ingeniería y operaciones afines / Engineering ʸ-backscattering Compton camera One-side imaging Geant4 Retrodisersión ʸ Imagenología por un costado Cámara compton |
| description |
Abstract. Imaging via ʸ backscattering techniques are suitable for non destructive and non invasive methods to determine the amount and distribution of matter in objects, and these are very advantageous techniques when the access to both sides of the sample, unlike in the transmission case, is not possible. A ʸ-backscattering device dubbed the Compton Camera, developed at GSI (Darmstadt, Germany), has been modified and studied at Grupo de Física Nuclear de la Universidad Nacional de Colombia (Bogotá, Colombia). The Compton Camera is based on the so called Gamma-ray Compton Backscattering (GCB) technique and it uses back-toback emission of two ʸ-rays, from positron annihilation, to construct a bi-dimensional image representing the density distribution of the sample in the field-of-view of the camera. The main objective of this work is to increase the understanding of the response of the Compton Camera, in particular its image-forming process, to strengthen the data analysis and to evaluate limitations of the actual device. In this work a state-of-the-art simulation of the camera is presented, using the Geant4 simulation toolkit. The simulation was validated through comparison with experimental results, also the contribution of single and multiple Compton scatterings to image-forming process was determined, time-of-flight of ʸ-rays before detection was quantifiled and some limitations of the technique were studied. In order to enhance the image quality some digital image processing methods were implemented, a theoretical model of backscattering intensity is presented, and possible improvements to the current experimental setup are suggested. The Compton Camera can be used with success to identify hidden objects behind metallic walls, to locate high density objects buried in sand and it is very useful on diagnosis of metallic surfaces. Furthermore, the camera can be used in the detection of anti-personnel landmines buried in farming soil. The simulated images and their comparison with the experimental ones suggest already methods to improve the present experimental setup aiming for the proposal of the next generation of the Compton Camera prototype. |
| publishDate |
2014 |
| dc.date.none.fl_str_mv |
2014 2019-07-03T19:20:17Z 2019-07-03T19:20:17Z |
| dc.type.none.fl_str_mv |
Trabajo de grado - Maestría info:eu-repo/semantics/masterThesis info:eu-repo/semantics/acceptedVersion http://purl.org/coar/resource_type/c_bdcc http://purl.org/coar/version/c_ab4af688f83e57aa Text http://purl.org/redcol/resource_type/TM |
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masterThesis |
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acceptedVersion |
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https://repositorio.unal.edu.co/handle/unal/75222 http://bdigital.unal.edu.co/39740/ |
| url |
https://repositorio.unal.edu.co/handle/unal/75222 http://bdigital.unal.edu.co/39740/ |
| dc.language.none.fl_str_mv |
spa |
| language |
spa |
| dc.relation.none.fl_str_mv |
Universidad Nacional de Colombia Sede Bogotá Facultad de Ciencias Departamento de Física Departamento de Física Flechas García, David Camilo (2014) Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit. Maestría thesis, Universidad Nacional de Colombia. |
| dc.rights.none.fl_str_mv |
Derechos reservados - Universidad Nacional de Colombia Atribución-NoComercial 4.0 Internacional http://creativecommons.org/licenses/by-nc/4.0/ info:eu-repo/semantics/openAccess |
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Derechos reservados - Universidad Nacional de Colombia Atribución-NoComercial 4.0 Internacional http://creativecommons.org/licenses/by-nc/4.0/ |
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openAccess |
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application/pdf application/pdf |
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reponame:Repositorio UN instname:Universidad Nacional de Colombia instacron:Universidad Nacional de Colombia |
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Universidad Nacional de Colombia |
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Universidad Nacional de Colombia |
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Universidad Nacional de Colombia |
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Repositorio UN |
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Repositorio UN |
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Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkitFlechas García, David Camilo51 Matemáticas / Mathematics53 Física / Physics62 Ingeniería y operaciones afines / Engineeringʸ-backscatteringCompton cameraOne-side imagingGeant4Retrodisersión ʸImagenología por un costadoCámara comptonAbstract. Imaging via ʸ backscattering techniques are suitable for non destructive and non invasive methods to determine the amount and distribution of matter in objects, and these are very advantageous techniques when the access to both sides of the sample, unlike in the transmission case, is not possible. A ʸ-backscattering device dubbed the Compton Camera, developed at GSI (Darmstadt, Germany), has been modified and studied at Grupo de Física Nuclear de la Universidad Nacional de Colombia (Bogotá, Colombia). The Compton Camera is based on the so called Gamma-ray Compton Backscattering (GCB) technique and it uses back-toback emission of two ʸ-rays, from positron annihilation, to construct a bi-dimensional image representing the density distribution of the sample in the field-of-view of the camera. The main objective of this work is to increase the understanding of the response of the Compton Camera, in particular its image-forming process, to strengthen the data analysis and to evaluate limitations of the actual device. In this work a state-of-the-art simulation of the camera is presented, using the Geant4 simulation toolkit. The simulation was validated through comparison with experimental results, also the contribution of single and multiple Compton scatterings to image-forming process was determined, time-of-flight of ʸ-rays before detection was quantifiled and some limitations of the technique were studied. In order to enhance the image quality some digital image processing methods were implemented, a theoretical model of backscattering intensity is presented, and possible improvements to the current experimental setup are suggested. The Compton Camera can be used with success to identify hidden objects behind metallic walls, to locate high density objects buried in sand and it is very useful on diagnosis of metallic surfaces. Furthermore, the camera can be used in the detection of anti-personnel landmines buried in farming soil. The simulated images and their comparison with the experimental ones suggest already methods to improve the present experimental setup aiming for the proposal of the next generation of the Compton Camera prototype.Las técnicas para generar imágenes por retrodispersión de rayos-ʸ son métodos no destructivos y no invasivos para determinar la cantidad y distribución de materia en los objetos, que además presentan una ventaja cuando no se puede tener acceso a ambos costados dela muestra de interes, a diferencia de las técnicas de transmisión. El dispositivo llamado La Cámara Compton, que usa la retrodispersión ʸ para generar imágenes, fue desarrollado en el GSI (Darmstadt, Germany), y ha sido modificado y estudiado en el Grupo de Física Nuclear de la Universidad Nacional de Colombia (BogotáColombia). La Cámara Compton se basa en la técnica conocida como Gamma-ray Compton Backscattering (GCB) y aprovecha la correlación espacial que existe entre los dos fotones generados en la aniquilación positrónica para construir una imagen bidimensional que representa la distribución de densidad, desde el punto de vista de la cámara, de la muestra bajo estudio. Con este trabajo se espera mejorar el entendimiento del funcionamiento de la Cámara Compton y, en particular, del proceso de formación de la imagen, fortalecer los métodos de análisis y evaluar las limitaciones del prototipo actual. En este trabajo se presenta una simulación muy completa de la cámara usando la herramienta computacional Geant4, la cual se validó a través de la comparación con resultados experimentales, así mismo se determinó la contribución de las dispersiones Compton simples y múltiples a la formación de las imágenes, se determinaron los tiempos de vuelo de los rayos ʸ desde la emisión hasta la detección, y se estudiaron algunas de las limitaciones de la técnica. Además, se implementaron algunos algoritmos de procesamiento digital de imágenes con el fin de mejorar la calidad de la imagen, se presenta un modelo para predecir el número de fotones retrodispersados, y finalmente se proponen algunas posibles mejoras al prototipo experimental actual. La Cámara Compton puede ser usada con éxito en la búsqueda de objetos ocultos detrás de paredes metálicas, en la localización de objetos de alta densidad enterrados en arena, y es muy útil para el estudio y diagnóstico de superfiies metálicas. Además, los resultados obtenidos sugieren que la cámara puede ser utilizada en la detección de minas antipersonales enterradas en tierra. Producto de la comparación entre los resultados simulados y los resultados experimentales se proponen mejoras al dispositivo experimental actual, que van a ser muy importantes para proponer la siguiente versión de la Cámara Compton.MaestríaCristancho Mejía, Luis Fernando2019-07-03T19:20:17Z2019-07-03T19:20:17Z2014Trabajo de grado - Maestríainfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/acceptedVersionhttp://purl.org/coar/resource_type/c_bdcchttp://purl.org/coar/version/c_ab4af688f83e57aaTexthttp://purl.org/redcol/resource_type/TMapplication/pdfapplication/pdfhttps://repositorio.unal.edu.co/handle/unal/75222http://bdigital.unal.edu.co/39740/spaUniversidad Nacional de Colombia Sede Bogotá Facultad de Ciencias Departamento de FísicaDepartamento de FísicaFlechas García, David Camilo (2014) Evaluation of the photographic capabilities of a Compton Camera device using the GEANT4 simulation toolkit. Maestría thesis, Universidad Nacional de Colombia.Derechos reservados - Universidad Nacional de ColombiaAtribución-NoComercial 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc/4.0/info:eu-repo/semantics/openAccessreponame:Repositorio UNinstname:Universidad Nacional de Colombiainstacron:Universidad Nacional de Colombia2024-07-05T04:40:53Z |
| score |
15,812429 |