As atividades específicas do 238U, 226Ra, 210Pb, 232Th e 40K, foram medidas, utilizando-se a técnica de espectrometria gama de alta resolução, em amostras de solo coletadas em três furos com 2,10 m de profundidade e feitos com trado manual. O material amostrado é um latossolo desenvolvido sobre rochas quartzo-feldspáticas. O local da amostragem, no terreno do Instituto de Botânica da Secretaria do Meio Ambiente do Estado de São Paulo, possui uma cobertura vegetal densa que, junto com a camada superficial de solo, não é perturbada desde, pelo menos, 1938. Os 0,60 m superior da camada de solo amostrada correspondem aos horizontes O e A, enquanto que os 1,50 m restantes correspondem ao horizonte B. As medidas de atividade específica do 210Pb foram corrigidas para compensar os efeitos da absorção da radiação gama com 46,5 keV pela matriz de solo. O procedimento de correção baseado na literatura disponível, foi adaptado com o desenvolvimento de equações apropriadas para representar a geometria de detecção em que as medidas foram realizadas. Os resultados mostram que as atividades específicas do 238U e do 226Ra variam pouco em função da profundidade. O perfil de atividades do 238U parece refletir a distribuição dos minerais de argila no perfil de solo, enquanto que o perfil de atividades do 226Ra apresenta um valor praticamente constante em todo o solo analisado. O perfil de atividades do 210Pb mostra um leve enriquecimento desse isótopo nos horizontes O e A em relação ao restante do perfil. Com a exceção dos horizontes mais superficiais, o 226Ra está em desequilíbrio radioativo com o 238U e o solo apresenta razões de atividade 226Ra/238U da ordem de 0,90. O 210Pb está em desequilíbrio radioativo com o 226Ra sendo que as razões de atividade 210Pb/226Ra variam em torno de 0,7 na maior parte do perfil. A atividade específica do 210Pb é inferior à atividade específica do 226Ra em valores que variam de 8 Bq/kg a 18 Bq/kg. A série do 232Th está em equilíbrio radioativo secular em todas as amostras analisadas. As atividades específicas mais baixas do 232Th são observadas nos horizontes O e A. O horizonte B é enriquecido em 232Th o que reflete a maior concentração de argilas nesse horizonte. O 40K está distribuído de forma irregular ao longo do perfil de solo analisado e apresenta atividades específicas variando desde valores abaixo do limite de detecção do laboratório até 37,8 Bq/kg. / The specific activities of 238U , 226Ra, 210Pb, 232Th and 40K were measured, and the 226Ra/238U and 210Pb/226Ra activity ratios were calculated for samples collected in a 2.10 m deep soil profile in a preserved area of the São Paulo Botanic Garden. The sampling site is covered by dense vegetation that, together with the upper soil layer, has not been disturbed since, al least, 1938. The upper 0.60 m of the soil profile corresponds to the O and A soil horizons, whereas the remaining 1.50 m of the profile corresponds to the B horizon. The 210Pb specific activity measurements were corrected for the attenuation of the 46.5 keV gamma radiation by the soil mineral matrix. The attenuation correction procedure is based on the available literature and was adapted to represent the detection geometry of the measurements. The results show that the uranium series is in radioactive disequilibrium in most of the sampled soil. The 226Ra/238U activity ratios vary around 0.9 whereas the 210Pb/226Ra activity ratios resulted in a mean value of 0.7. The unsupported 210Pb specific activities are between -8 Bq/kg and -18 Bq/kg. The 232Th series is in secular radioactive equilibrium in the whole sampled soil layer. The 232Th specific activity distribution seems to reflect the concentration of clay minerals in the soil horizon B. The 40K radionuclide is irregulary distributed in the whole sampled soil layer and it?s specific activities varying from below detection limit to about 37.8 Bq/kg.

As doses resultantes da contaminação ambiental por radônio e seus filhos em residências geram discussões entre pesquisadores sobre os reais danos biológicos que elas possam causar. De um lado as agências de proteção radiológica adotam o modelo proposto por vários pesquisadores de que qualquer dose, por menor que seja, pode produzir dano. Por outro lado, outros cientistas acham desnecessárias medidas restritivas pois os danos biológicos só seriam prováveis para doses bem mais altas que aquelas ocasionadas em exposições residenciais. Independente da relação entre dose e efeito, a disponibilidade de dados sobre concentrações em residências serve de base para que estudos epidemiológicos possam ser realizados, e uma melhor análise dos efeitos biológicos de baixas doses se efetive. O objetivo deste trabalho é contribuir para a dosimetria de radônio e filhos através da determinação da concentração média de radônio e dos filhos alfa emissores em residências da cidade de São Paulo. Foram efetuadas medidas separadas da concentração de 222Rn e da concentração total de emissores alfa no ar, também foram realizadas estimativas da dose gama durante o estudo. Com as concentrações medidas foi possível a estimativa da concentração de filhos de radônio (218Po e 214Po), os elementos que mais contribuem para a dose no corpo humano. Para a realização deste trabalho foram utilizados monitores passivos de 222Rn com detectores plásticos LR115 e CR39, e detectores termoluminescentes. Três métodos diferentes de medida da concentração em separado de 222Rn foram testados, sendo dois com LR115 e um com CR39. Os detectores plásticos foram analisados em um sistema semi-automático de análise de imagens. Foram realizadas duas exposições de aproximadamente seis meses (em 2003 e 2004) em residências da cidade São Paulo e um total de 170 residências foi monitorado. A média geométrica da concentração de 222Rn obtida na cidade foi 25 Bq.m-3. Valores entre 11 e 109 Bq.m-3 foram encontrados. O resultado verificado na cidade de São Paulo é menor que a média mundial, é aproximadamente 1/3 da concentração média encontrada na Europa e, é comparável a outros valores na América do Sul. Foi feita uma análise das concentrações obtidas de acordo com as características das residências e posição geográfica na cidade. Os resultados apontam que locais com maior ventilação, mais afastadas do solo e com piso de carpete ou madeira apresentam menores níveis de contaminação ambiental. Por outro lado, menor taxa de ventilação, localização em andares térreos e pisos de cimento ou cerâmica contribuem para o aumento das concentrações. Houve pequena variação das concentrações com relação à posição geográfica na cidade, sendo que as maiores concentrações foram encontradas no extremo sul da cidade nos distritos de Parelheiros e Grajaú. Não foi encontrada correlação entre a concentração total de emissores alfa e a taxa de dose gama. A média geométrica da concentração de filhos de radônio no ar resultou em 77 Bq.m-3. O valor encontrado para a contribuição dos filhos de radônio na concentração total de emissores alfa é muito significativo, aproximadamente 70% do total, maior que o verificado em estudo similar. Também não foi encontrada forte correlação entre a concentração de 222Rn e a de filhos no ar, o que indica a necessidade da determinação das duas componentes para uma dosimetria mais adequada. / There are several discussions among scientists about the actual biological effects that doses due to radon and progeny contamination in residences can cause. Radiation rotection agencies adopted the model proposed by various scientists, that any dose, with no threshold, might produce biological damage. On the other hand, other scientists believe that very restrict laws are excessive, because damages would be possible only for doses higher than those received in dwellings. Regardless of the dose-effect relation, data about radon concentration in residences are important and are a base for epidemiological studies that improve the knowledge about biological effects of low doses. The aim of this work is to contribute to radon and daughters dosimetry by the assessment of radon and progeny (alpha emitters) concentration in dwellings of the city of São Paulo. Radon concentration was measured separately from total alpha emission concentration in air. Also, gamma doses were evaluated during this study. With the measured concentrations it was possible to estimate the concentration of radon progeny (218Po and 214Po), the radionuclides which most contribute to the human dose. Monitoring was carried out using time-integrated passive 222Rn monitors with LR115 and CR39 plastic detectors, and thermoluminescent detectors. Three methods of radon concentration measurements were tested, two based on LR115 and the third with CR39. Plastic detectors were analyzed with a semi-automatic image analysis system. Two exposures were made during approximately six months (in 2003 and 2004) in dwellings in the city of São Paulo. 170 residences were monitored. Results show a geometric mean of 25 Bq.m-3 for 222Rn concentration. Values ranged from 11 to 109 Bq.m-3. The result is lower than the world average, it is approximately 1/3 of the average concentration in the Europe, and it is comparable to other results in South America. An analysis of radon and progeny concentrations in relation to residence characteristics and geographic position was made. Results point that places with good ventilation, second floor constructions and carpet or wood floor covering present lower concentrations. On the other hand, low ventilation rate, ground floor construction, and cement or ceramics covering contribute to higher radon and progeny concentration. There was low variation of levels with the geographic position in the city, and the higher concentrations were found in the south of the city, in Parelheiros and Grajaú districts. No correlation was found between total alpha emission concentration and gamma dose rate. Results of progeny concentration in the air show geometric mean of 77 Bq.m-3. The contribution of radon daughters to the total alpha emission oncentration is very significant, approximately 70%, higher than the value found in a similar work. No strong correlation was found between 222Rn concentration and progeny concentration in the air, indicating that the determination of both the concentrations is necessary for a more adequate dosimetry.

Os radionuclídeos naturais de origem primordial, ou terrestres, são encontrados em quantidades variadas em todo meio ambiente. Nas residências, um importante incremento de dose (INDOOR), é devido aos materiais de construção, que contribuem tanto com a dose externa gama, proveniente das séries do 238U, 235U e 232Th e do radionuclídeo isolado 40K, quanto com a dose interna que é devida principalmente à inalação do 222Rn. Uma vez que rochas graníticas são amplamente utilizadas como materiais de construção, tanto estruturais como de revestimento, estas podem tornar-se uma importante fonte de dose, dependendo das concentrações de radioatividade que apresentem, e da forma e quantidade que são aplicadas nas construções. Neste trabalho foi gerado um banco de dados para rochas graníticas do escudo cristalino paranaense (principalmente da Região Metropolitana de Curitiba, RMC), que são utilizadas na construção civil avaliando em termos de proteção radiológica o incremento da dose, externa e interna, causada pela utilização destes materiais. Também foram estudadas as possíveis correlações entre a concentração de atividade de 226Ra, taxa de exalação de 222Rn, densidade, porosidade e composição química (teor de óxidos constituintes) nestas amostras. A dose externa foi avaliada por meio da técnica de espectrometria gama com detector de germânio hiperpuro, onde as concentrações de atividade dos radionuclídeos 226Ra, 232Th e 40K são os parâmetros utilizados em modelos dosimétricos (Índices Dosimétricos), os quais estabelecem limites máximos permitidos de acordo com forma, quantidade e aplicação do material de construção. Para o cálculo da dose efetiva anual externa foi adotado o modelo de sala com dimensões 4 m x 5 m x 2,8 m e todas as paredes são revestidas internamente com granitos de espessura de 2 cm e considerando o tempo de exposição anual de 7000 h, conforme sugerido pela Comissão Européia de Proteção Radiológica para materiais de revestimento interno supercial. A exposição interna foi avaliada a partir da concentração de radônio no ar da sala modelo, simulada a partir do valor da taxa de exalação supercial de 222Rn. A taxa de exalação foi determinada pela técnica de detecção passiva utilizando detectores sólidos de traços nucleares (CR-39) por meio da técnica do recipiente selado, considerando taxa de ventilação de 0,5 h-1 e tempo de exposição anual de 7000 h . Os resultados destes estudos mostram que o incremento da dose efetiva anual externa variou de (62 ± 3) μSv.a-1 a (138 ± 1) μSv.a-1 e o incremento da dose efetiva anual interna variou de (0,39 ± 0,04) μSv.a-1 a (70 ± 4) μSv.a-1. Estes valores estão abaixo do limite máximo de 1 mSv.a-1 sugerido pela Comissão Européia de Proteção Radiológica, portanto os granitos avaliados neste trabalho podem ser utilizados sem implicações radiológicas desde que obedecido o cenário descrito. Os valores obtidos para a contribuição devida à dose interna variaram de 1 % a 78 % dos valores obtidos para a respectiva dose externa, mostrando que a contribuição do radônio varia fortemente com o tipo da rocha. Os resultados das correlações entre taxa de exalação supercial de 222Rn, concentração de atividade de 226Ra, densidade, porosidade e principais óxidos componentes das amostras, mostraram que, em termos de inuência na fração de emanação do radônio, o parâmetro mais importante é a densidade, devido a baixa porosidade e a semelhança em termos de composição química entre as amostras. / Primordial, or terrestrial natural radionuclides, are found in dierent amounts in the environment. In dwellings, an important dose increment is due to building materials, which contribute for both the external gamma dose from the radionuclides of the 238U, 235U and 232Th series and the natural 40K and the internal dose, due mainly to 222Rn inhalation. Once granitic rocks are widely used both as construction materials or structural flooring, those rocks can become an important dose source, depending on the content of concentrations of radioactivity, and the construction application. In this work, a database for granitic rocks of the crystalline shield of Paraná (mainly in the Metropolitan Region of Curitiba, RMC), used in civil construction, was generated, evaluating in terms of radiological protection the external and internal dose increments, caused by the use of these materials. Also, possible correlations between the 226Ra activity concentration, the 222Rn exhalation rate, density, porosity and chemical composition (oxide content) in these samples had been studied. The external dose was assessed by gamma-ray spectrometry with High-Purity Germanium detectors, where the activity concentration of the radionuclides 232Th, 226Ra and 40K are the parameters used in dosimetric models (Dosimetric Indexes), which established limits in accordance with the form, amount and application of material of construction. For the calculation of the annual eective external dose it was assumed a room model with dimensions of 4 m x 5 m x 2.8 m and all walls internally covered with 2 cm thickness of granite and an annual exposure time of 7000 h as suggested by the European Commission of Radiological Protection for internal supercial coating materials. The internal exposure was assessed from the radon concentration in the air of the room model, simulated from the supercial exhalation rate of 222Rn. The exhalation rate was determined by the passive detection technique with the Solid State Nuclear Track Detectors (CR-39) and the sealed can technique, assuming a ventilation rate of 0.5 h-1 and an annual exposure time of 7000 h. The results for this studies show that the annual eective dose ranged from (62 ± 3) μSv.y1 to (138 ± 1) μSv.y-1 and the internal annual eective dose ranged from (0,39 ± 0,04) μSv.y-1 to (70 ± 4) μSv.y-1. These values are below the maximum limit of 1 mSv.y-1 suggested by the European Commission of Radiological Protection, meaning that the granitic rocks evaluated can be used without radiological implications since the considered scenario is obeyed. The values obtained for the contribution due to the internal dose ranged from 1 % to 78 % of the values obtained for the respective external dose showing the radon contribution varies strongly with the rock type. The results of the correlations between 222Rn supercial exhalation rate, 226Ra activity concentration, density, porosity and major oxides of the samples, showed that, in terms of inuence in the emanation fraction of radon, the most important parameter is the density, due to low porosity and similarity in terms of chemical composition amid the studied samples.

<p> </p><p>Radioactive waste has been accumulated at CERN as unavoidable consequence of the use of particle accelerators. The elimination of this waste towards the final repositories in France and Switzerland requires the determination of the radionuclide inventory. In order to calculate the residual induced radioactivity in the waste, it is necessary to determine the spectra of secondary particles which are responsible for the material activation. In complex irradiation environments like in an accelerator tunnel it is expected that the secondary particle spectra vary with the characteristics of the machine components in a given section of tunnel. In order to obtain the production rates of the radionuclides of interest the spectra of secondary particles are to be folded with the appropriate cross sections. Though technically feasible, it would be impractical to calculate the particle spectra in every area of any machine and for all possible beam loss mechanisms. Moreover, a fraction of the waste has unknown radiological history, which makes it impossible to associate an item of waste to a precise area of the machine. Therefore it is useful to try to calculate “representative spectra”, which shall apply to a relatively large part of the accelerator complex at CERN. This thesis is dedicated to the calculation of representative spectra in the arcs of the 450 GeV proton synchrotron, SPS, at CERN. The calculations have been performed using the Monte Carlo code FLUKA. Extensive simulations have been done to assess the dependence of proton, neutron and pion spectra on beam energy, size of the nearby machine component and position with respect to the beam-loss point. The results obtained suggest that it is possible to define one single set of representative spectra for all the arcs of the SPS accelerator, with a minor error associated with the use of these. </p><p> </p>

<p>The aim of this study was to test whether one could use the same methods as used for sampling heavy metals and apply them to radioactive elements. Furthermore a sampling protocol was developed, the first of its kind, for the sampling of radioactive elements in fractured rock aquifers. This was achieved by initially examining local as well as international manuals and methods. The aforementioned was done in conjunction with a literature review of the movement of radioactive elements in these fractured rock aquifers. Beaufort West was utilised as a study area and the geology, hydrogeology and topography was outlined. Background radioactivity was generally acceptable except for two samples which were anomalously high. Taking cognisance of the methods used, as well as those previously applied in the area and abroad, a sampling protocol for radioactive elements in fractured rock aquifers was developed and attached as an appendix. In conclusion it was suggested that multiple methods be tested on one well in order to check whether similar results would occur. This would thus determine the best applicable methods. Also it was proposed that a new method, called DGT sampling, be applied in order to gain a time weighted average of the heavy metals and radioactive elements in groundwater. It could also be clearly seen, by comparing historical data and the current data, that the methods used for sampling heavy metal can be applied to radioactivity.</p>

The prompt production of &chi / c quarkonia is studied in proton-proton collisions at 7 TeV, using data collected by CMS in 2011 corresponding to an integrated luminosity of 4.6 fb &minus / 1. The &chi / c mesons are reconstructed through their radiative decays to J/&psi / and photon with J/&psi / &rarr / &mu / +&mu / &minus / . The photons are reconstructed through their conversion in electron-positron pairs in the tracking detector which gives a mass resolution sufficient for resolving these states. The ratio of the prompt production cross sections for the &chi / c1 and &chi / c2 states, &sigma / (&chi / c2)/&sigma / (&chi / c1), has been determined as a function of the J/&psi / transverse momentum between 7 and 25 GeV/c.

Radioactive waste has been accumulated at CERN as unavoidable consequence of the use of particle accelerators. The elimination of this waste towards the final repositories in France and Switzerland requires the determination of the radionuclide inventory. In order to calculate the residual induced radioactivity in the waste, it is necessary to determine the spectra of secondary particles which are responsible for the material activation. In complex irradiation environments like in an accelerator tunnel it is expected that the secondary particle spectra vary with the characteristics of the machine components in a given section of tunnel. In order to obtain the production rates of the radionuclides of interest the spectra of secondary particles are to be folded with the appropriate cross sections. Though technically feasible, it would be impractical to calculate the particle spectra in every area of any machine and for all possible beam loss mechanisms. Moreover, a fraction of the waste has unknown radiological history, which makes it impossible to associate an item of waste to a precise area of the machine. Therefore it is useful to try to calculate “representative spectra”, which shall apply to a relatively large part of the accelerator complex at CERN. This thesis is dedicated to the calculation of representative spectra in the arcs of the 450 GeV proton synchrotron, SPS, at CERN. The calculations have been performed using the Monte Carlo code FLUKA. Extensive simulations have been done to assess the dependence of proton, neutron and pion spectra on beam energy, size of the nearby machine component and position with respect to the beam-loss point. The results obtained suggest that it is possible to define one single set of representative spectra for all the arcs of the SPS accelerator, with a minor error associated with the use of these.

Scherk-Schwarz reductions are a generalization of Kaluza-Klein reductions in which the higher dimensional fields are allowed to have a dependence on the compactiifed coordinates. This is possible only if the higher dimensional theory has a global symmetry and the dependence is dictated by this symmetry. In this thesis we consider generalised Scherk Schwarz reductions of supergravity and superstring theories with twists by electromagnetic dualities that are symmetries of the equations of motion but not of the action, such as the S-duality of $D=4, N=4$ super-Yang-Mills coupled to supergravity. The reduction cannot be done on the action itself, but must be done either on the field equations or on a duality invariant form of the action, such as one in the doubled formalism in which potentials are introduced for both electric and magnetic fields. The resulting theory in odd dimensions has massive form fields satisfying a self-duality condition $dA sim m*A$. We apply these methods to theories in $D=4,6,8$, and obtain new gauged supergravity theories with massive form fields, with Chern-Simons like couplings and with a scalar potential in $D=3,5,7$.

A delayed-coincidence spectrometer system was developed to measure nuclear lifetimes in the picosecond region by the centroid-shift method. liming signals were derived from two plastic scintillators. A specially constructed NaI(Tl) detector was used to detect the gamma-rays which were Corrpton-scattered from one of the plastic scintillators. Energy identification was achieved by sumning the signals from the plastic detector and the NaI(Tl) detector to give the full energy photopeaks. In order to test the effectiveness of the system, the mean lives of the first excited states of Ni60 and Ba134 were measured. The 1.0-psec mean life in Ni60 could not be measured with the present system. The gamma-gamma and beta-gamma coincidence experiments gave the mean life of the first excited state of Ba134 as 6.1 ±0.8 psec and 4.8 ±0.6 psec, respectively. It is concluded that the shortest mean life that can reliably be measured by the present system is about 5 psec.Ball State UniversityMuncie, IN 47306

Radiative Decays of the phi-meson to the scalar mesons f0(980) and a0(980) are investigated within the framework of charged kaon loop model for both point-like scalar mesons and for scalar mesons with extended structure. Then, the radiative phi-meson decay into neutral K-meson is studied via a two step mechanism in which the scalar mesons couple the final state to the phi-meson through the charged kaon loop. The branching ratio of this decay is calculated and it is shown that this reaction will not provide a significant background to the measurements of phi-meson into neutral K-meson states decay for testing CP violation.