Nuclear Detectors
Mostrando 13-24 de 30 artigos, teses e dissertações.
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13. Investigation of ultra-high sensitivity klystron cavity transducers for broadband resonant-mass gravitational wave detectors.
We show that, with a suitable choice of the parameters of the gravitational wave detector Mario Schenberg, with technological accessible parameters (using state-of-art electronics), its sensitivity curve can be improved over the current project curve to become competitive with interferometric detectors in a frequency band of ~1500 Hz, in the region from 1000
Publicado em: 2008
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14. 66Ga como padrão de calibração de raios de altas energias para detectores HPGe / Ga66 as a standard for high energy gamma rays
This work involves the study of the peak efficiency and response function of HPGe detectors for gamma rays in the energy range of 2 to 5 MeV, somewhat above the energy range of the available calibration sources for gamma spectroscopy. It is part of a high energy (up to 20MeV) -ray project to obtain intensity of rays from photo nuclear reactions produced with
Publicado em: 2008
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15. AvaliaÃÃo dos parÃmetros dosimÃtricos em feixes de FÃtons de Radioterapia usando fototransistor SMT
One of the biggest challenges in radiotherapy dosimetry is to certify that the prescribed dose is given to the patient. For this, it is necessary to use small detectors to evaluate the beam parameters. Current dosimetry is realized with detectors that highlight problems: high cost, difficulty in handling, absence of real time readout, complex and delayed obt
Publicado em: 2008
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16. Measurement of conversion coeficients between air kerma and personal dose equivalent and backscatter factors for diagnostic x-ray beams / Determinação experimental dos coeficientes de conversão de Kerma no ar para o equivalente de dose pessoal, Hp(d), e fatores de retroespalhamento em feixes de raios-x diagnostico
Em proteção radiológica dois conjuntos de grandezas são importantes, as de proteção e as operacionais. Ambas podem ser relacionadas a partir de coeficientes de conversão com grandezas físicas básicas como o kerma. Para feixes de radiação utilizados em radiodiagnóstico nas qualidades da Comissão Internacional de Eletrotécnica (IEC), os coeficien
Publicado em: 2008
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17. Digital system to characterize solid state nuclear track detectors
A digital system to characterize solid state nuclear track detectors(SSNTD) has been developed. It was used in the study of two detectors and its performance evaluated by comparing the obtained results with those determined by using an analog system, already in use for such purpose. The comparison of the results together with the feasibility and rapidness in
Brazilian Journal of Physics. Publicado em: 2007-06
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18. Avaliação da exposição ocupacional ao 222Rn no galpão da salvaguardas do IPEN / ASSESSMENT OF 222Rn OCCUPATIONAL EXPOSURE AT IPEN NUCLEAR MATERIALS STORAGE SITE
In this study it was assessed the occupational exposure to 222Rn at ipen nuclear materials storage site through the committed effective dose received by workers exposed to this radionuclide. The radiation dose was calculated through the radon concentrations at nuclear materials storage site. Radon concentrations were determined by passive detection method wi
Publicado em: 2007
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19. Fator S astrofisico para a reação de captura 4He(t,g)7Li pela investigação da reação de transferência elástica no sistema 7Li + 4He / Astrophysical S factor for the 4He(t,g)7Li capture reaction by the investigation of the elastic-transfer reaction in the 7Li + 4He system
The normalization coefficient for the non-resonant part of the 3H(alpha,gama)7Li capture reaction (or alternately, the astrophysical S-factor) was obtained with the indirect method ANC (Asymptotic Normalization Coefficients). In this method the spectroscopic factor (or alternately, the ANC) is extracted from the investigation of a peripheral transfer reactio
Publicado em: 2007
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20. Desenvolvimento de cristais baseados em iodeto de Césio para aplicação como detectores de radiação / Development of crystals based in cesium iodide for application as radiation detectors
Cintiladores inorgânicos com tempo de decaimento de luminescência rápido, densidade alta e boa produção de luz têm sido objeto de estudos para aplicações em física nuclear, física de energias altas, tomografia nuclear e outros campos da ciência e da engenharia. Cristais de cintilação baseados em iodeto de césio (Csl) são materiais que apresent
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/06/2006
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21. Espectrometria de nÃutrons com sistema de esferas de Bonner utilizando detectores passivos termoluminescentes
NÃutrons sÃo partÃculas sem carga que podem ser removidos do nÃcleo atÃmico por algum processo de rearranjo nuclear, e assim, apresentar um espectro em energia compreendido desde baixa energia (En <2x10-7 eV) atà alta energia (En >100 MeV). Sabe-se no entanto que, a energia dos nÃutrons pode variar significativamente dentro de um mesmo ambiente, o que
Publicado em: 2006
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22. Development of a tomographic system for online dose measurements in BNCT (Boron Neutron Capture Therapy)
Within our activities on accelerator-based boron neutron capture therapy (BNCT) carried out at the Tandar Laboratory (Comisión Nacional de Energía Atómica, Argentina) we present here the study and design of a tomographic imaging system for the measurement of the spatial distribution of the absorbed dose during a BNCT session. The 10B (n,alpha) 7Li boron n
Brazilian Journal of Physics. Publicado em: 2005-09
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23. Influence of the solar and density perturbations on the neutrino parameters
There are reasons to believe that the solar matter density fluctuates around an equilibrium profile. One of these reasons is a resonance between the Alfvén waves and the g-modes inside the Sun that creates spikes in the density profile. The neutrinos are created in the solar core and passing through these spikes feel them as a noisy perturbation, whose corr
Brazilian Journal of Physics. Publicado em: 2004-12
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24. The advanced gamma ray tracking array AGATA
New accelerator facilities for radioactive-ion beams and high-intensity stable beams will start operation in a few years. Although these beams will provide interesting opportunities for exploring unknown territories of the nuclear landscape, the experimental conditions will be very challenging and, indeed, the nuclear structure community has realized that a
Brazilian Journal of Physics. Publicado em: 2004-09