abstract: Total dose sensing systems (or radiation detection systems) have many applications, ranging from survey monitors used to supervise the generated radioactive waste at nuclear power plants to personal dosimeters which measure the radiation dose accumulated in individuals. This dissertation work will present two different types of novel devices developed at Arizona State University for total dose sensing applications. The first detector technology is a mechanically flexible metal-chalcogenide glass (ChG) based system which is fabricated on low cost substrates and are intended as disposable total dose sensors. Compared to existing commercial technologies, these thin film radiation sensors are simpler in form and function, and cheaper to produce and operate. The sensors measure dose through resistance change and are suitable for applications such as reactor dosimetry, radiation chemistry, and clinical dosimetry. They are ideal for wearable devices due to the lightweight construction, inherent robustness to resist breaking when mechanically stressed, and ability to attach to non-flat objects. Moreover, their performance can be easily controlled by tuning design variables and changing incorporated materials. The second detector technology is a wireless dosimeter intended for remote total dose sensing. They are based on a capacitively loaded folded patch antenna resonating in the range of 3 GHz to 8 GHz for which the load capacitance varies as a function of total dose. The dosimeter does not need power to operate thus enabling its use and implementation in the field without requiring a battery for its read-out. As a result, the dosimeter is suitable for applications such as unattended detection systems destined for covert monitoring of merchandise crossing borders, where nuclear material tracking is a concern. The sensitive element can be any device exhibiting a known variation of capacitance with total ionizing dose. The sensitivity of the dosimeter is related to the capacitance variation of the radiation sensitive device as well as the high frequency system used for reading. Both technologies come with the advantage that they are easy to manufacture with reasonably low cost and sensing can be readily read-out. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017

A utilização de detectores de radiação é de imensa importância na área de dosimetria, pois permite a quantificação da dose absorvida no meio. Uma técnica interessante para esta finalidade é o uso de detectores por cintilação. Estudos recentes com cintiladores plásticos e líquidos demonstraram a viabilidade do uso de detecção de cintilação por uma câmera digital com sensor CCD ou CMOS. Desse modo, este trabalho tem como objetivo desenvolver um dosímetro cintilador de baixo custo para viabilidade de seu uso e, de um sistema de detecção de cintilação através de uma câmera digital, para que assim pudesse ser realizada sua caracterização dosimétrica. O sistema dosimétrico foi construído a partir de um cintilador líquido a base de antraceno. Dosimetricamente verificou-se uma linearidade de resposta para a dose de 0,1 a 25,53 Gy, para a taxa de dose de 6,66 Gy/min e uma pequena diminuição da sensibilidade do dosímetro quando aumentada a taxa de dose de irradiação. Com relação à dependência energética, foi verificado um aumento na sensibilidade do dosímetro de 10,8% ao se variar a energia de 100 a 160 kVp. Quando comparado a um cintilador comercial, apresentou uma intensidade de sinal reduzida e, em uma análise de reprodutibilidade, obteve-se uma variação máxima de 2% em relação a repetição de uma mesma medida. O cintilador líquido apresentou baixa estabilidade pré e pós-irradiação, com uma variação de cor e redução do sinal ao decorrer dos dias. Para medidas bidimensionais o sistema montado mostrou-se promissor, uma vez que em medidas de deposição de dose com a profundidade para várias energias de feixes, verificou-se o aumento da penetração da radiação com o aumento da energia do feixe e as medidas de penumbra de um feixe parcialmente blindado com 2 mmPb apresentaram um valor de 1,79 cm, considerando o tipo de tubo gerador e blindagem utilizada. Por toda a caracterização realizada o sistema dosimétrico mostrou-se aplicável para dosimetria, desde que operado considerando as características apresentadas. / The utilization of radiation detector is important in the dosimetric area, because it allow the quantification of absortion dose in the medium. An interesting tehnique for this finalitypurpose is the use of scintillation detector. Recent studies with plastic scintillators and liquid scintillators have demonstrated the feasibility of using scintillation detection by a digital camera with CCD or CMOS sensors. Thus, this study is the intent to develop a low-cost scintillation dosimeter for the feasibility of its use and detection scintillation system through by a digital camera, with the finality of dosimetric characterization. The dosimetric system was constructed from using liquid scintilator based anthracene. A linearity dose response between 0.1 to 25.53 Gy was found for the dose rate of 6.66 Gy/min and the dosimeter sensibility was decreased when the dose rate increased. When varied the energy from 100 to 160 kVp, was verified an increased of 10.8% in the dosimeter sensibility, due the energy dependence. When compared to a commercial dosimeter, it shows signal intensity decreased and, the study of reproducibility, a maximum variation of 2% was obtained in relation to the repetition of the same measure. The liquid scintillator presented low stability before and after irradiation, with a color variation and signal reduction over the days. For two-dimensional measurements the assembled system proved to be promising, since in dose deposition measurements with the depth for several beam energies, the penetration of the radiation was increased with the increase of the beam energy and the penumbra measurements of a narrow beam with 2mmPb presented a value of 1.79 cm, considering the type of generator tube and narrow used. Throughout the characterization carried out the dosimetric system proved to be applicable for dosimetry, if operated considering the characteristics presented.

Water is a major component of living organisms, which can be 70-85% of the weight of cells. For this reason, water is a main target of ionizing radiations and plays a central role in radiobiology. Heavy ions, electrons and photons interact with water molecules; mainly by ionization and excitation. Neutrons interact with water molecules by elastic interactions, which generate recoil ions that will create ionizations and excitations in water molecules. These fast events (~10[superscript -12] s) lead to the formation of Reactive Oxygen Species (ROS). The ROS, in particular the hydroxyl radical (¨OH), interact with neighbour molecules such as proteins, lipids and nucleic acids by chemical interaction. Microbeams can irradiate selectively either the external membrane, the cytoplasm and the cell nucleus. These studies have shown that cell survival is greatly reduced when the nucleus is irradiated, but that this is not the case when cytoplasm or cell membrane is irradiated. Thus, DNA is a very sensitive site to ionizing radiation and ROS. For this reason, DNA has long been considered the most important molecule to explain radiobiological effects such as cell death. However, this concept has been challenged recently by new experimental results that have shown that cells which have not been directly in contact with radiation are also affected. This is called the bystander effect. Further studies have shown that a group of cells and their environment reacts collectively to radiation. A hypothesis put forward to explain this radiobiological phenomenon is that a irradiated cell will secrete signalling molecules that will affect non-irradiated cells. The implicated phenomenon and molecules are poorly understood at this moment. The purpose of this work is to improve our comprehension of the phenomenon in the microsecond that follows the irradiation. To these ends, a new Monte-Carlo simulation program of water radiolysis by photons has been generated. For photons of energy <2 MeV, they interact with water mainly by Compton and photoelectric effects, which create energetic electrons in water. The created electrons are then followed by our existing programs to simulate the radiolysis of water by photons. Similarly, a new code has been built to simulate the neutrons interaction with water. This code simulates the elastic collisions of a neutron with water molecules and calculates the number and energy of recoil protons and oxygen ions. The main part of this Ph.D. work was the generation of a non-homogeneous Monte-Carlo Step-By-Step (SBS) simulation code of non-homogeneous radiation chemistry. This new program has been used successfully to simulate radiolysis of water by ions of various LET, pH, ion types ([superscript 1]H[superscript +], [superscript 4]He[superscript 2+], [superscript 12]C[superscript 6+]) and temperature. The program has also been used to simulate the dose-rate effect and the Fricke and Ceric dosimeters. More complex systems (glycine, polymer gels and HCN) have also been simulated.

This diploma thesis is focused on material printing of light dosimeters, especially printing of dosimeters for visible light and two types of UV radiation dosimeters. The aim of this work was to convert optimized systems from laboratory scale to pilot plant and to prepare individual systems for large-scale printing. The experimental part deals with the preparation and gradual scaling of compositions to a pilot scale, including optimization of individual components. Problems which were found during scaling up are discussed. A roll-to-roll material printer with slot-die technique was used to convert to a pilot scale. The prepared layers were exposed and their color changes was studied in detail. In addition to printing optimization, the thicknesses of the prepared layers and their resistance were determined, as well as tests of shelf life and reaction of dosimeters to ozone. According to the tests which were performed, guidelines for quality control of light dosimeters printing were compiled.

The thesis deals with the issue of operative dosimetry, to be specific, with personal dosimetry. The objective of the thesis is to compare several parameters, such as the dose, direction and energy dependence, in two types of electronic dosimeters made by the firm Siemens (type EPD1) and by the firm MGP Instruments (type DMC 2000XB). In the first section of my thesis the personal monitoring and related data such as quantities used to monitor external irradiation are introduced. In the next section the operative monitoring, focused mainly on electronic but also on thermoluminescent and radiophotoluminescent dosimetry, is described. The results of the irradiation (exposure) of electronic personal dosimeters of types EPD1 and DMC 2000XB are included in the thesis and the measured values are statistically processed. The dose, direction and energy dependence of both types of these dosimeters is evaluated and put into diagrams.

Neste trabalho foram estudadas as propriedades dosimétricas de aluminatos de cálcio e lítio sintetizados pela técnica sol-gel e codopados/dopados com os terras-raras európio e térbio. No aluminato de cálcio as caracterizações morfológicas apresentaram fase predominante do Ca12Al14O33 com grãos variando entre 150 - 270 &#956;m, sistema poroso de 200 - 290 nm. As incorporações dos dopantes foram observadas com a formação dos compostos de CaEuAl3O7 e CaTbAl3O7 para as calcinações em 1100 °C e apresentaram os melhores resultados luminescentes. A caracterização luminescente revelou alta intensidade LOE para a amostra codopada com 0,8 mol% de Eu,Tb e baixa intensidade TL-UV que não pode ser correlacionado com a LOE na faixa de doses estudadas (irradiações-? de 0,08 - 16 Gy). Foram reportados três picos na TL-VIS, 92, 216 e 310 °C para o aluminato puro e 92, 135 e 216 °C para o codopado. Usando a técnica de LOE, a mínima dose detectável (MDD) obtida foi de 16 mGy com a amostra codopada e o menor fading foi de 5% do pico de 216 °C para TL-Vis do puro. Pelos estudos de Tm-Tstop e deconvoluções (CGCD) foi possível ajustar as curvas TL-VIS com 6 picos de cinética de ordem geral e 4 componentes CW-LOE com 2.ª ordem. Pela LM-LOE foram obtidos elevados valores de seções de choque de fotoionização, o que justificou a alta sensibilidade óptica deste material. No aluminato de lítio (calcinação a 900 °C) a caracterização morfológica revelou grãos com dispersão de 25 - 70 µm, fase predominando de &#947;- LiAlO2. Após a incorporação dos dopantes de Tb houve a formação dos compostos Al2Tb4O9 e TbAlO3 e de estruturas longitudinais de ~500 nm nas superfícies dos grãos. As amostras apresentaram um sistema luminescente altamente complexo, com sobreposição de 6 picos na TL-VIS do aluminato puro (65, 100, 140, 203, 304 e 370 °C), 7 picos na TL-VIS do dopado (70, 100, 140, 184, 211, 295 e 340 °C). A MDD obtida foi de 5 mGy pela técnica LOE e de 2,2 mGy do pico de 211 °C da TL-VIS do aluminato de lítio dopado com Tb. O menor fading obtido foi 1,5 % do pico de 140 °C do aluminato puro na TL-VIS. Pelos estudos de Tm-Tstop e CGCD, as curvas TL-VIS foram ajustadas utilizando 9 picos e as de TL-UV com 8 e 7 picos para as amostras pura e dopada, respectivamente. Neste aluminato também foram observados fenômenos inéditos de ganho de luminescência de até 2 vezes a intensidade LOE inicial oriundos das transferências energéticas mediante estimulação térmica e óptica pós irradiação. Um modelo fenomenológico de bandas simplificado utilizando duas armadilhas profundas de competição está sendo proposto neste trabalho. O aluminato de lítio dopado apresentou elevada intensidade LOE e estabilidade térmica mesmo após 300 °C de tratamento térmico, entretanto, demonstrou alta sensibilidade à exposição óptica. As curvas de LM-LOE foram ajustadas com 4 componentes de elevadas seções de choque de fotoionização o que confere com a alta sensibilidade óptica reportada. / In this work dosimetric proprieties of calcium and lithium aluminates synthetized by solgel technique and codoped/doped with rare earth europium and terbium were studied. Morphological characterization showed Ca12Al14O33 (C12A7) as a predominant phase, with grains size distribution between 150 -270 &#956;m and a porous system between 200-290 nm for the sample calcined at 1100 °C. This calcination revealed the greatest luminescence results. The dopant incorporation phases, observed by XRD patterns, matches to CaEuAl3O7 and CaTbAl3O7 compounds. Luminescence characterization showed intense OSL signal when the samples were codoped with the concentration of 0,8 mol% of Eu,Tb. However, due to low TL-UV intensity, OSL signal could not be correlated with TL-UV glow curve of this aluminate. TL-VIS detection showed peaks at, 92, 216 and 310 °C for pure calcium aluminate and at 92, 135 and 216 °C for the codoped one. The lowest minimum detectable dose (MDD) obtained was 16 mGy in OSL detection from codoped calcium aluminate and the lowest fading was 5% from aluminate for 216 °C TL peak in VIS region. By Tm-Tstop studies and CGCD deconvolution TL-VIS glow curve could be fitted using 6 peaks, with general order kinetic, and CW-OSL decay curve was fitted with 4 components of second order. LMOSL experiments resulted in high photo-ionization cross-sections, which explains the optical response of this sample. For lithium aluminate, morphological characterization showed grains size dispersion between 25- 70 &#956;m, with predominant phase of &#947;-LiAlO2 for pure sample, as well Al2Tb4O9 and TbAlO3 for Tb to doped one. Furthermore, SEM images showed long and longitudinal structures (500 nm) emerging from grain surface after Tb doping process. Luminescence characterization showed intense OSL, TL-UV and TL-VIS signals for sample doped with 0,2 mol% and calcined at 900 °C, which comprehends a complex luminescence system, with overlapping of 6 peaks in TL-VIS for pure aluminate (65, 100, 140, 203, 304 and 370 °C), 7 peaks for TL-VIS of doped one (70, 100, 140, 184, 211, 295 and 340 °C). The MDD obtained was 5 mGy for OSL and 2,2 mGy for 211 °C for TL-VIS peak, both for 0,2 mol% of Tb. The lowest fading was 1,5% for pure lithium aluminate of the 140 °C TL-VIS peak . By Tm-Tstop studies and CGCD deconvolution, TL-VIS glow curves were fitted using 9 peaks and for TLUV region, 8 and 7 peaks for pure and doped samples, respectively. Strictly, lithium aluminate revealed several energetic transfers evolving two possible depth trap explain by a simplified model of luminescence bands. The energetic transfer increments the final luminescence of the sample up to 2 times the initial OSL signal. Besides, even after 300 °C of thermal treatment, OSL signal keep its intense luminescence. However, the samples are highly sensitize by optical stimulation. In LM-OSL deconvolution, 4 components with elevated photo-ionization cross-sections were determined and fitted the experimental curve, which explains the highly optical sensitization.

Desde a descoberta dos raios X por Wilhelm Conrad Roentgen em 1895, a medicina vem fazendo uso da radiação ionizante para o tratamento de alguns cânceres. No entanto, para que os tratamentos se façam com maior precisão, há a necessidade de um controle de qualidade adequado, que é da responsabilidade do físico médico de um serviço de radioterapia. Do aprimoramento do dosímetro químico Fricke em 2000 [BERO et al, 2000], através da adição de alaranjado de xilenol e gelatina de origem animal 300 Bloom, alcançou-se um aumento da sensibilidade e estabilidade da substância química. Porém, o custo da importação da gelatina e de um espectrofotômetro para as medidas de absorção óptica na determinação da dose absorvida poderia dificultar a utilização desse dosímetro num serviço de radioterapia. O presente trabalho busca apresentar uma alternativa simples e barata para atender às situações apresentadas através da substituição da gelatina importada por uma nacional (atualmente em teste) constituindo o novo dosímetro FXGB, que permitiu uma caracterização prévia de feixes de fótons (1,25 MeV) e elétrons (5, 7 e 10 MeV), além da determinação de parâmetros físicos para elétrons como fator e perfil de campo e porcentagem de dose profunda. As medidas foram realizadas com um protótipo leitor portátil (RADIARE III) desenvolvido [FELIPE, 2001] e otimizado [ZAIAS, 2006] em nosso grupo de pesquisa. Dessas medidas foi comprovado que o novo dosímetro é adequado para ser utilizado em medidas de dose absorvida na radioterapia para fótons e elétrons. / Since the X rays discovery for Wilhelm Conrad Roentgen in 1895, the medicine started to use the ionizing radiation for some cancers treatments. However, to obtain higher precision in the treatments is necessary an adequate quality control, which is a medical physicist responsibility in the service. This work was developed to assist the medical physicist on the quality control through an simple, inexpensive and commercially accessible dosimetry. From the chemical dosimetry Fricke improvement in 2000 [BERO et al, 2000], through the orange xilenol and 300 Bloom gelatin addition, it was shown a sensibility and chemicalstability improvement. However, the high cost and difficulty to import the gelatin and necessity to utilize an spectrophotometer to determine the absorbed dose lead us to find another new gelatin adequate for the measurements. The new FXGB dosimeter was characterized for photons (1,25 MeV) and electrons (5, 7 and 10 MeV) and applied for some electrons beam physical determination as: field factor, field profile and depth dose percentage (PDD). From the obtained results, the FXGB dosimetric system (FXGB gel + prototype RADIARE III) show a promising option to assist the quality control in an radiotherapy service.

O gel radiocrômico Turnbull Blue (TBG) é sensível a raios gamma e x. Este composto tem sido utilizado em dosimetria de radiações ionizantes devido à sua capacidade de simular tecido biológico quando exposto à radiação de alta energia. Após sua irradiação, o TBG sofre uma mudança de cor: o aspecto amarelo torna-se azul devido à formação do corante Turnbull Blue. Essa alteração de cor produz uma larga banda de absorção na faixa espectral do visível, com pico localizado em 690 nm. A intensidade desta banda é proporcional à dose de radiação absorvida. Entretanto, o comportamento do TBG, quando exposto a radiações menos energéticas, como luz visível e ultravioleta, ainda não é conhecido. Considerando as recomendações de organizações internacionais sobre os riscos do uso de tais radiações, esta pesquisa teve como objetivo caracterizar a resposta do TBG, quando irradiado por diferentes fontes ultravioletas e visíveis, tais como lâmpadas fluorescentes, LEDs e um simulador solar. O tempo entre a exposição do gel e a leitura de sua resposta foi estudado, assim como a influência da utilização de fontes com diferentes irradiâncias e diferentes temperaturas de irradiação. Um espectrômetro, operando na faixa espectral de 350 nm a 900 nm, foi utilizado para mensurar a mudança de cor no gel. Os resultados mostraram que o gel possui diferentes sensibilidades de acordo com a faixa espectral entregue pela fonte: a radiação UVC produziu a alteração de cor mais intensa, seguida pela UVB, UVA e visível, respectivamente. A temperatura de irradiação e a irradiância da fonte tiveram influência considerável na mudança de cor do TBG. Os resultados mostraram que é possível usar o gel TBG como um dosímetro de radiação óptica, desde que fatores de correção relacionados à irradiância da fonte e temperatura de irradiação sejam levados em consideração. / The radiochromic gel Turnbull Blue (TBG) is sensitive to gamma and x-rays. This compound has been utilized in ionizing radiation dosimetry, since it acts as biological tissue simulator when exposed to high-energy radiation. Subsequently to its radiation, TBG shows a color shift: the original yellow aspect becomes blue due to the production of the colorant Turnbull Blue. Such chromic shift yields a broad absorption band in the visible spectral range, with a peak located at 690 nm. The intensity of this band is proportional to the absorbed radiation dose. However, the behavior of TBG when exposed to less energetic radiation, e.g. ultraviolet and visible light, remains unclear. Considering the recommendations of international organizations regarding the risks of using such type of radiation, this research aimed to characterize the TBG response when irradiated by different ultraviolet and visible sources as well as to determine its sensitivity to the radiation in the UV-Visible spectral range. Furthermore, this investigation evaluated the viability of TBG as an optical dosimeter. During this study, the gel was exposed to different non-ionizing radiation sources, such as fluorescent lamps, LEDs and a sun simulator. The time between the gel exposition and the measurement of its response was studied, as well as the influence of different source irradiances and temperatures of irradiation. A spectrometer operating on the 350-900 nm spectral range has measured the gel color shift. The results showed different sensitivities according to the spectral range delivered by the source: UVC has produced the most intense change in color, followed by UVB, UVA and visible, respectively. The temperature of irradiation and the irradiance provided by the sources have shown considerable influence on the color shift. The results showed that it is possible to use the TBG gel as optical radiation dosimeter. The use of correction factors for temperature of irradiation and irradiance of the source are mandatory.

Neste trabalho foram estudadas as propriedades dosimétricas de aluminatos de cálcio e lítio sintetizados pela técnica sol-gel e codopados/dopados com os terras-raras európio e térbio. No aluminato de cálcio as caracterizações morfológicas apresentaram fase predominante do Ca12Al14O33 com grãos variando entre 150 - 270 &#956;m, sistema poroso de 200 - 290 nm. As incorporações dos dopantes foram observadas com a formação dos compostos de CaEuAl3O7 e CaTbAl3O7 para as calcinações em 1100 °C e apresentaram os melhores resultados luminescentes. A caracterização luminescente revelou alta intensidade LOE para a amostra codopada com 0,8 mol% de Eu,Tb e baixa intensidade TL-UV que não pode ser correlacionado com a LOE na faixa de doses estudadas (irradiações-? de 0,08 - 16 Gy). Foram reportados três picos na TL-VIS, 92, 216 e 310 °C para o aluminato puro e 92, 135 e 216 °C para o codopado. Usando a técnica de LOE, a mínima dose detectável (MDD) obtida foi de 16 mGy com a amostra codopada e o menor fading foi de 5% do pico de 216 °C para TL-Vis do puro. Pelos estudos de Tm-Tstop e deconvoluções (CGCD) foi possível ajustar as curvas TL-VIS com 6 picos de cinética de ordem geral e 4 componentes CW-LOE com 2.ª ordem. Pela LM-LOE foram obtidos elevados valores de seções de choque de fotoionização, o que justificou a alta sensibilidade óptica deste material. No aluminato de lítio (calcinação a 900 °C) a caracterização morfológica revelou grãos com dispersão de 25 - 70 µm, fase predominando de &#947;- LiAlO2. Após a incorporação dos dopantes de Tb houve a formação dos compostos Al2Tb4O9 e TbAlO3 e de estruturas longitudinais de ~500 nm nas superfícies dos grãos. As amostras apresentaram um sistema luminescente altamente complexo, com sobreposição de 6 picos na TL-VIS do aluminato puro (65, 100, 140, 203, 304 e 370 °C), 7 picos na TL-VIS do dopado (70, 100, 140, 184, 211, 295 e 340 °C). A MDD obtida foi de 5 mGy pela técnica LOE e de 2,2 mGy do pico de 211 °C da TL-VIS do aluminato de lítio dopado com Tb. O menor fading obtido foi 1,5 % do pico de 140 °C do aluminato puro na TL-VIS. Pelos estudos de Tm-Tstop e CGCD, as curvas TL-VIS foram ajustadas utilizando 9 picos e as de TL-UV com 8 e 7 picos para as amostras pura e dopada, respectivamente. Neste aluminato também foram observados fenômenos inéditos de ganho de luminescência de até 2 vezes a intensidade LOE inicial oriundos das transferências energéticas mediante estimulação térmica e óptica pós irradiação. Um modelo fenomenológico de bandas simplificado utilizando duas armadilhas profundas de competição está sendo proposto neste trabalho. O aluminato de lítio dopado apresentou elevada intensidade LOE e estabilidade térmica mesmo após 300 °C de tratamento térmico, entretanto, demonstrou alta sensibilidade à exposição óptica. As curvas de LM-LOE foram ajustadas com 4 componentes de elevadas seções de choque de fotoionização o que confere com a alta sensibilidade óptica reportada. / In this work dosimetric proprieties of calcium and lithium aluminates synthetized by solgel technique and codoped/doped with rare earth europium and terbium were studied. Morphological characterization showed Ca12Al14O33 (C12A7) as a predominant phase, with grains size distribution between 150 -270 &#956;m and a porous system between 200-290 nm for the sample calcined at 1100 °C. This calcination revealed the greatest luminescence results. The dopant incorporation phases, observed by XRD patterns, matches to CaEuAl3O7 and CaTbAl3O7 compounds. Luminescence characterization showed intense OSL signal when the samples were codoped with the concentration of 0,8 mol% of Eu,Tb. However, due to low TL-UV intensity, OSL signal could not be correlated with TL-UV glow curve of this aluminate. TL-VIS detection showed peaks at, 92, 216 and 310 °C for pure calcium aluminate and at 92, 135 and 216 °C for the codoped one. The lowest minimum detectable dose (MDD) obtained was 16 mGy in OSL detection from codoped calcium aluminate and the lowest fading was 5% from aluminate for 216 °C TL peak in VIS region. By Tm-Tstop studies and CGCD deconvolution TL-VIS glow curve could be fitted using 6 peaks, with general order kinetic, and CW-OSL decay curve was fitted with 4 components of second order. LMOSL experiments resulted in high photo-ionization cross-sections, which explains the optical response of this sample. For lithium aluminate, morphological characterization showed grains size dispersion between 25- 70 &#956;m, with predominant phase of &#947;-LiAlO2 for pure sample, as well Al2Tb4O9 and TbAlO3 for Tb to doped one. Furthermore, SEM images showed long and longitudinal structures (500 nm) emerging from grain surface after Tb doping process. Luminescence characterization showed intense OSL, TL-UV and TL-VIS signals for sample doped with 0,2 mol% and calcined at 900 °C, which comprehends a complex luminescence system, with overlapping of 6 peaks in TL-VIS for pure aluminate (65, 100, 140, 203, 304 and 370 °C), 7 peaks for TL-VIS of doped one (70, 100, 140, 184, 211, 295 and 340 °C). The MDD obtained was 5 mGy for OSL and 2,2 mGy for 211 °C for TL-VIS peak, both for 0,2 mol% of Tb. The lowest fading was 1,5% for pure lithium aluminate of the 140 °C TL-VIS peak . By Tm-Tstop studies and CGCD deconvolution, TL-VIS glow curves were fitted using 9 peaks and for TLUV region, 8 and 7 peaks for pure and doped samples, respectively. Strictly, lithium aluminate revealed several energetic transfers evolving two possible depth trap explain by a simplified model of luminescence bands. The energetic transfer increments the final luminescence of the sample up to 2 times the initial OSL signal. Besides, even after 300 °C of thermal treatment, OSL signal keep its intense luminescence. However, the samples are highly sensitize by optical stimulation. In LM-OSL deconvolution, 4 components with elevated photo-ionization cross-sections were determined and fitted the experimental curve, which explains the highly optical sensitization.

Made available in DSpace on 2016-04-27T18:11:54Z (GMT). No. of bitstreams: 1 Joana DArc Aparecida Salgado.pdf: 633670 bytes, checksum: 89b7c4535d7f94caddc5a7dde577a01c (MD5) Previous issue date: 2012-01-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Introduction: The musicians are part of a professional category under the risk of auditory issues and health complaints, due to electronically amplified music exposure. Objective: Measuring sound levels and identifying auditory and non-auditory complaints on pop-rock musicians groups. Method: 34 male pop-rock musicians, ages between 26 and 60 years old were evaluated. The subjects answered a questionnaire composed of health history, complaints related to hearing and information about music exposure. The noise dosimeter was applied on the musicians during a band concert on a nightclub in São Paulo. It was used a dosimeter type 1, properly calibrated, in which the microphone was positioned behind the musician s ear, 5 minutes before the beginning of the presentation. Results: The prevalence of auditory complaints, loud sound intolerance and the felling of occluded ears was 20,6%. From all, 50% of the sample reported the thought of being exposure to that sound can damage their hearing. The majority (27, 79,4%) of the musicians work in this area for further than 10 years. The highest sound level obtained on Lmax variation medium maximum levels, Lavg - average levels and Lmin - medium minimum levels in dB (A) were of 129,6; 119,1 and 94,5 (respectively). The values were further above the maximum level daily allowed, according to the occupational legislation. Conclusions: Dosimeter can be useful on levels investigation. Although, measures for musicians protection must be immediately taken, so that it can avoid deleterious effects on this population health / Introdução: Os músicos representam uma categoria profissional sob risco de problemas auditivos e queixas de saúde, em decorrência da exposição à música eletronicamente amplificada. Objetivo: Medir os níveis sonoros e identificar queixas auditivas e não auditivas em músicos de bandas de pop-rock. Método: Foram avaliados 34 músicos de pop-rock, do sexo masculino, com idades entre 26 e 60 anos. Os sujeitos responderam um questionário com dados sobre histórico de saúde, queixas relacionadas à audição e informações sobre exposição à música. Foi realizada a dosimetria de ruído no músico durante uma apresentação da banda em uma casa noturna de São Paulo. Para tanto foi utilizado um dosímetro do tipo 1, devidamente calibrado, cujo microfone foi posicionado próximo à orelha do músico, cinco minutos antes do início da apresentação. Resultados: A prevalência das queixas auditivas intolerância a som intenso e sente os ouvidos tampados foi de 20,6%. Do total, 50% da amostra relataram achar que o som ao qual está exposto afeta sua saúde. A maioria (27, 79,4%) dos músicos trabalha na profissão há mais de 10 anos. Os maiores níveis sonoros obtidos nas variáveis Lmax nível médio máximo, Lavg nível médio e Lmin nível médio mínimo em dB (A) foram de 129,6; 119,1 e 94,5 (respectivamente). E os menores foram de 105,9; 94,5 e 62,2 (respectivamente). Os valores estavam muito acima dos níveis máximos diários permitidos, segundo a Legislação Trabalhista. Conclusões: A dosimetria pode ser útil na investigação dos níveis. Entretanto, medidas de proteção aos músicos devem ser imediatamente adotadas com o objetivo de evitar os efeitos deletérios à saúde dessa população