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Tagged photons from 81 to 116 MeV were used to measure elastic Compton scat- tering cross sections from deuterium and carbon targets at the MAX-lab facility in Lund. Scattered gamma rays were detected in three very large NaI(Tl) crystals with sufficient energy resolution to isolate deuterium elastic yields at scattering angles of 60°, 90°, 120° and 150°. Calculations indicate that back-angle Compton scattering on deuterium in this energy range is sensitive to the electric and magnetic polarizabilities of the nucleon. Results of this research were obtained with improved beam tagging system conditions compared to previous elastic Compton scattering experiments from deuterium.

Neste trabalho foram realizadas medidas de espalhamento Compton em tecidos mamários normais e neoplásicos (benignos e malignos) em experimentos usando radiação síncrotron e tubo de raios X, com o objetivo de determinar as densidades eletrônicas destes tecidos. As energias e ângulos de espalhamento utilizados foram respectivamente 14,0 keV e 150º (x = 1,09 Å-1) para as medidas usando radiação síncrotron e 17,44 e 90º (x = 0,99Å-1) para as medidas usando um tubo de raios X. Os resultados de densidades eletrônicas obtidos foram comparados com dados experimentais e teóricos previamente publicados, mostrando considerável concordância entre eles (diferenças menores que 5%). Comparações estatísticas foram realizadas nas distribuições obtidas, verificando-se que os tecidos normais adiposos se diferenciam de todos outros tipos de tecidos investigados (P<0,001). Também se observou a tendência de as neoplasias malignas apresentarem maior densidade eletrônica que os tecidos normais fibrosos e neoplasias benignas, fato relacionado às características histológicas e metabólicas de seu crescimento. Os resultados obtidos sugerem que é possível utilizar esta técnica para caracterizar e diferenciar os tipos de tecidos, apontando a possibilidade de sua utilização como ferramenta complementar ao diagnóstico do câncer de mama. / In this work we have been measured Compton scattering from normal and neoplastic (benign and malignant) in experiments using synchrotron radiation and X-rays tube, in order to determine of electronic densities of these tissues. The energies and scattering angles used were respectively 14,0 keV and 150º (x = 1,09 Å-1) for the measurements using synchrotron radiation and 17,44 and 90º (x = 0,99Å-1) for the measurements using a X-ray tube. The results of electronic densities obtained were compared with experimental and theoretical data published previously, showing considerable agreement among them (differences smaller than 5%). Statistical comparisons were accomplished in the obtained distributions, showing that the adipose normal tissue differ of all other types of tissues (P<0.001). Moreover, our results show a tendency of the malignant neoplasias to have an elevated electronic density higher than the fibrous normal tissues and benign neoplasias, fact related to histological and metabolic characteristics of its growth. The obtained results suggest that it is possible to use this technique to characterize and to differentiate the breast tissues, pointing the possibility of its use as complementary tool to the diagnosis of the breast cancer.

Neste trabalho foram realizadas medidas de espalhamento elástico e inelástico em tecidos mamários normais e neoplásicos (benignos e malignos) usando uma energia de 17,44 keV (radiação K? ¬- Mo) e um ângulo de espalhamento de 90º (x = 0,99Å-1) com o objetivo de determinar as densidades eletrônicas (?e), número atômico efetivo (Zef) e largura a meia altura (LMA) do pico de espalhamento inelástico destes tecidos. Também foram estudadas por meio de simulações computacionais imagens obtidas por técnica de tomografia de espalhamento Compton. As metodologias experimentais foram verificadas através da análise de materiais de referência. Os valores de densidades eletrônicas e números atômicos efetivos obtidos foram comparados com dados experimentais e teóricos previamente publicados, mostrando uma boa concordância com estes (diferenças menores que 5%). Os valores de LMA obtidos indicam a possibilidade de uso deste parâmetro para obter informação sobre composição dos tecidos e se mostraram correlacionados com os valores de Zef. Os resultados também mostram que existem diferenças de ?e, Zef e LMA entre os grupos de tecidos, as quais estão associadas à composição e à histologia dos tecidos investigados. Por fim, os resultados do estudo técnica de imagem por espalhamento Compton permitiu avaliar a influência de diferentes fatores relacionados ao feixe de radiação, à geometria e à amostra, que determinam a qualidade das imagens obtidas. / In this work we have been measured elastic and inelastic scattering from normal and neoplastic (benign and malignant) breast tissues using a photon energy of 17.44 keV (K? radiation ¬- Mo) and a scattering angle of 90º in order to determine the electron densities (?e), effective atomic number (Zef) and full width at half maximum (FWHM) of inelastic peak of these tissues. Compton scattering imaging techniques was also studied using computational simulation. The experimental methods were checked by analyzing of standard reference materials. The values of electron densities and effective atomic numbers obtained were compared with theoretical and experimental data previously published, showing good agreement between them (differences smaller than 5%). The values of FWHM indicate the possibility of using the FWHM for obtain information about the composition of tissues showing correlation with the values of Zef. The results also show that there are differences of ?e, Zef and FWHM between groups of tissues which are associated with the composition and histology of the investigated tissues. Finally, the results of the study of the Compton scattering imaging technique allowed assessing the influence of various factors, related to the radiation beam, geometry sample, which determine the image quality.

Photon mass attenuation coefficients are indispensable input parameters for use in several disciplines. They are of value for medical diagnostics, radiation therapy, material science, etc. Currently, photon mass attenuation coefficients derived from model calculations are widely used. This project directly measured the photon mass attenuation coefficients of water and a number of water based solutions. These measurements were made using a High Purity Germanium (HPGe) detector allowing for increased resolution beyond traditional techniques. Four sources were used (\Ba, \Eu, \Cs, \Am) producing multiple photons of interest over the range of 40 keV to 1.4 MeV, allowed for simultaneous collection of data and a refining of uncertainties beyond past techniques. Direct measurements using a new liquid technique supported the validity of Bragg's additive law, allowing for the mass attenuation coefficient of a constituent element to be calculated from a set of independent measurements. This technique allows materials not easily directly measured to be determined without an overburdening increase in uncertainty. The same direct measurements showed a deviation from the currently relied upon National Institute of Standards and Technology (NIST) database - XCOM. Investigations of the deviation and surrounding references showed XCOM being at most accurate to 5 \% relative uncertainty.

Ultrashort, nearly monochromatic hard X-ray pulses enrich the understanding of the dynamics and function of matter, e.g., the motion of atomic structures associated with ultrafast phase transitions, structural dynamics and (bio)chemical reactions. Inverse Compton backscattering of intense laser pulses from relativistic electrons not only allows for the generation of bright X-ray pulses which can be used in a pumpprobe experiment, but also for the investigation of the electron beam dynamics at the interaction point. The focus of this PhD work lies on the detailed understanding of the kinematics during the interaction of the relativistic electron bunch and the laser pulse in order to quantify the influence of various experiment parameters on the emitted X-ray radiation. The experiment was conducted at the ELBE center for high power radiation sources using the ELBE superconducting linear accelerator and the DRACO Ti:sapphire laser system. The combination of both these state-of-the-art apparatuses guaranteed the control and stability of the interacting beam parameters throughout the measurement. The emitted X-ray spectra were detected with a pixelated detector of 1024 by 256 elements (each 26μm by 26μm) to achieve an unprecedented spatial and energy resolution for a full characterization of the emitted spectrum to reveal parameter influences and correlations of both interacting beams. In this work the influence of the electron beam energy, electron beam emittance, the laser bandwidth and the energy-anglecorrelation on the spectra of the backscattered X-rays is quantified. A rigorous statistical analysis comparing experimental data to ab-initio 3D simulations enabled, e.g., the extraction of the angular distribution of electrons with 1.5% accuracy and, in total, provides predictive capability for the future high brightness hard X-ray source PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) and potential all optical gamma-ray sources. The results will serve as a milestone and starting point for the scaling of the Xray flux based on available interaction parameters of an ultrashort bright X-ray source at the ELBE center for high power radiation sources. The knowledge of the spatial and spectral distribution of photons from an inverse Compton scattering source is essential in designing future experiments as well as for tailoring the X-ray spectral properties to an experimental need.

Neste trabalho foram realizadas medidas de espalhamento Compton em tecidos mamários normais e neoplásicos (benignos e malignos) em experimentos usando radiação síncrotron e tubo de raios X, com o objetivo de determinar as densidades eletrônicas destes tecidos. As energias e ângulos de espalhamento utilizados foram respectivamente 14,0 keV e 150º (x = 1,09 Å-1) para as medidas usando radiação síncrotron e 17,44 e 90º (x = 0,99Å-1) para as medidas usando um tubo de raios X. Os resultados de densidades eletrônicas obtidos foram comparados com dados experimentais e teóricos previamente publicados, mostrando considerável concordância entre eles (diferenças menores que 5%). Comparações estatísticas foram realizadas nas distribuições obtidas, verificando-se que os tecidos normais adiposos se diferenciam de todos outros tipos de tecidos investigados (P<0,001). Também se observou a tendência de as neoplasias malignas apresentarem maior densidade eletrônica que os tecidos normais fibrosos e neoplasias benignas, fato relacionado às características histológicas e metabólicas de seu crescimento. Os resultados obtidos sugerem que é possível utilizar esta técnica para caracterizar e diferenciar os tipos de tecidos, apontando a possibilidade de sua utilização como ferramenta complementar ao diagnóstico do câncer de mama. / In this work we have been measured Compton scattering from normal and neoplastic (benign and malignant) in experiments using synchrotron radiation and X-rays tube, in order to determine of electronic densities of these tissues. The energies and scattering angles used were respectively 14,0 keV and 150º (x = 1,09 Å-1) for the measurements using synchrotron radiation and 17,44 and 90º (x = 0,99Å-1) for the measurements using a X-ray tube. The results of electronic densities obtained were compared with experimental and theoretical data published previously, showing considerable agreement among them (differences smaller than 5%). Statistical comparisons were accomplished in the obtained distributions, showing that the adipose normal tissue differ of all other types of tissues (P<0.001). Moreover, our results show a tendency of the malignant neoplasias to have an elevated electronic density higher than the fibrous normal tissues and benign neoplasias, fact related to histological and metabolic characteristics of its growth. The obtained results suggest that it is possible to use this technique to characterize and to differentiate the breast tissues, pointing the possibility of its use as complementary tool to the diagnosis of the breast cancer.

Neste trabalho foram realizadas medidas de espalhamento elástico e inelástico em tecidos mamários normais e neoplásicos (benignos e malignos) usando uma energia de 17,44 keV (radiação K? ¬- Mo) e um ângulo de espalhamento de 90º (x = 0,99Å-1) com o objetivo de determinar as densidades eletrônicas (?e), número atômico efetivo (Zef) e largura a meia altura (LMA) do pico de espalhamento inelástico destes tecidos. Também foram estudadas por meio de simulações computacionais imagens obtidas por técnica de tomografia de espalhamento Compton. As metodologias experimentais foram verificadas através da análise de materiais de referência. Os valores de densidades eletrônicas e números atômicos efetivos obtidos foram comparados com dados experimentais e teóricos previamente publicados, mostrando uma boa concordância com estes (diferenças menores que 5%). Os valores de LMA obtidos indicam a possibilidade de uso deste parâmetro para obter informação sobre composição dos tecidos e se mostraram correlacionados com os valores de Zef. Os resultados também mostram que existem diferenças de ?e, Zef e LMA entre os grupos de tecidos, as quais estão associadas à composição e à histologia dos tecidos investigados. Por fim, os resultados do estudo técnica de imagem por espalhamento Compton permitiu avaliar a influência de diferentes fatores relacionados ao feixe de radiação, à geometria e à amostra, que determinam a qualidade das imagens obtidas. / In this work we have been measured elastic and inelastic scattering from normal and neoplastic (benign and malignant) breast tissues using a photon energy of 17.44 keV (K? radiation ¬- Mo) and a scattering angle of 90º in order to determine the electron densities (?e), effective atomic number (Zef) and full width at half maximum (FWHM) of inelastic peak of these tissues. Compton scattering imaging techniques was also studied using computational simulation. The experimental methods were checked by analyzing of standard reference materials. The values of electron densities and effective atomic numbers obtained were compared with theoretical and experimental data previously published, showing good agreement between them (differences smaller than 5%). The values of FWHM indicate the possibility of using the FWHM for obtain information about the composition of tissues showing correlation with the values of Zef. The results also show that there are differences of ?e, Zef and FWHM between groups of tissues which are associated with the composition and histology of the investigated tissues. Finally, the results of the study of the Compton scattering imaging technique allowed assessing the influence of various factors, related to the radiation beam, geometry sample, which determine the image quality.