Made available in DSpace on 2014-10-09T12:25:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:17Z (GMT). No. of bitstreams: 1 01000.pdf: 4057835 bytes, checksum: 0b012d0fbd5d28f8059716382ad5d9a5 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

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Made available in DSpace on 2014-10-09T12:25:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:17Z (GMT). No. of bitstreams: 1 01000.pdf: 4057835 bytes, checksum: 0b012d0fbd5d28f8059716382ad5d9a5 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

Made available in DSpace on 2014-10-09T12:32:43Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:03Z (GMT). No. of bitstreams: 1 03366.pdf: 1008030 bytes, checksum: 3c4f25e5172a0780c985f8c0dd3059a8 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

X-ray sensors are essential to many applications which are not limited to diagnostics and imaging technologies. Such sensors are extensively used in industry, medicine, research and space technology for applications such as safety, security, quality control, imaging and treatment. Depending on the effect of the radiation on the matter employed in the sensor, different types of X-ray sensors are fabricated. However, available techniques of X-ray detection have been under development due to specific shortcomings such as finite life time, low sensitivity, and post-processing requirements. This thesis is focused on design, fabrication and characterization of novel radiation sensors based on bio/nanomaterials. Bacteriorhodopsin (BR), a proton pump protein in the cell membrane of Halobacterium Salinarum, has been used to fabricate a sensor to measure dose and dose rate of X-ray beam in the kilovoltage and megavoltage energy range. The mass attenuation coefficients, effective atomic numbers and electron densities of BR and its comprising amino acids have been calculated for 1 keV-100 GeV photons to better understand the interaction of BR with X-ray photons. A theoretical formulation for calculating the change in the conductivity of nanoparticles under radiation is also provided. In particular, the dependence of radiation induced conductivity to irradiated particle size is given. In addition to that, an X-ray sensor based on thin film of bismuth sulfide has been fabricated using laser micromachining and chemical deposition techniques. This sensor has been characterized under a diagnostic X-ray machine with kilovoltage energy beam.

Made available in DSpace on 2014-10-09T12:29:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:47Z (GMT). No. of bitstreams: 1 01019.pdf: 1131567 bytes, checksum: 5ceeb9fd424e71ebd5852fcae5867465 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:24:13Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:12Z (GMT). No. of bitstreams: 1 01038.pdf: 2373326 bytes, checksum: 6700d091a3c179334b03259e2a632223 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

Made available in DSpace on 2014-10-09T12:29:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:47Z (GMT). No. of bitstreams: 1 01019.pdf: 1131567 bytes, checksum: 5ceeb9fd424e71ebd5852fcae5867465 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:24:13Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:12Z (GMT). No. of bitstreams: 1 01038.pdf: 2373326 bytes, checksum: 6700d091a3c179334b03259e2a632223 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP

The Thermal Radiation Group, a laboratory in the department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently working towards the development of a new technology for cavity-based radiometers. The radiometer consists of a 256-element linear-array thermopile detector mounted on the wall of a mirrored wedge-shaped cavity. The objective of this research is to provide analytical and experimental characterization of the proposed radiometer. A dynamic end-to-end opto-electrothermal model is developed to simulate the performance of the radiometer. Experimental results for prototype thermopile detectors are included. Also presented is the concept of the discrete Green's function to characterize the optical scattering of radiant energy in the cavity, along with a data-processing algorithm to correct for the scattering. Finally, a parametric study of the sensitivity of the discrete Green's function to uncertainties in the surface properties of the cavity is presented. / Master of Science