BIANCA GERALDO
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Resumo IPEN-doc 30976 Determination of Ni-63 on filters cartridges of water purification system of IPEN Research Reactor IEA-R12023 - SILVA, DEREK; GERALDO, BIANCA; VICENTE, ROBERTO; MARUMO, JULIO T.The Nuclear and Energy Research Institute (IPEN - CNEN/SP), has an open pool-type reactor that generates radioactive waste from the purification system of the cooling water, as resins, charcoal and filter cartridges. These wastes must be properly characterized before their treatment. The objective of this work is to describe one step of the characterization which is the radiochemical analysis of Ni-63 present in the filter cartridges. Ni-93 is one of the main radionuclides present. Based on the chemical recovery results obtained, it is possible to state that the method is valid for the determination of 63 Ni.Resumo IPEN-doc 27082 Radiochemical methodology applied to determination of gamma emitting radionuclides in waste samples from IEA-R1 reactor2017 - GERALDO, BIANCA; VICENTE, ROBERTO; GOES, MARCOS M.; MARUMO, JULIO T.Resumo IPEN-doc 24575 Eletronic response of photodiode coupled to a boron thin film2017 - COSTA, P.; COSTA, F.E.; RAELE, M.P.; ZAHN, G.; GERALDO, B.; VIEIRA JUNIOR, N.D.; SAMAD, R.E.; GENEZINI, F.A.A portable thermal neutron detector is proposed using a silicon photodiode coupled to a boron thin film. The aim of this work was to verify the effect in the electronic response of this specific photodiode due to boron deposition, since the direct deposition of boron in the semiconductor surface could affect its electrical properties specifically the p-type layer that affects directly the depletion region of the semiconductor reducing the neutron detector efficiency count. Three boron depositions with different thickness were performed in the photodiode (S3590-09) surface by pulsed laser deposition and the photodiode was characterized, before and after the deposition process, using a radioactive americium source. Energy spectra were used to verify the electronic response of the photodiode, due to the fact that it is possible to relate it to the photopeak pulse height and resolution. Spectra from the photodiode without and with boron film deposition were compared and a standard photodiode (S3590-04) that had the electronic signal conserved was used as reference to the pulse height for electronics adjustments. The photopeak energy resolution for the photodiode without boron layer was 10.26%. For the photodiode with boron deposition at different thicknesses, the resolution was: 7.64% (0.14 m), 7.30% (0.44 m) and 6.80% (0.63 m). From these results it is possible to evaluate that there was not any degradation in the silicon photodiode.