LUCIANA CAMINHA AFONSO
7 resultados
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Artigo IPEN-doc 11035 Estabilidade de camaras de ionizacao especiais para utilizacao em programas de controle da qualidade em radioterapia e radiodiagnostico2004 - AFONSO, L.C.; COSTA, A.M.; CALDAS, L.V.E.Artigo IPEN-doc 10645 Estabelecimento de campos padroes de radiacao X de energias medias no IPEN, nivel radioprotecao2005 - AFONSO, L.C.; CALDAS, L.V.E.Artigo IPEN-doc 12124 Evaluation of an ionization chamber response at small distances during dosimetry of gamma radiation beams2007 - AFONSO, LUCIANA C.; POTIENS, MARIA da P.A.; CALDAS, LINDA V.E.Artigo IPEN-doc 14347 Use of a standard ionization chamber at different distances in diagnostic radiology beams2009 - YOSHIZUMI, M.T.; AFONSO, L.C.; CALDAS, L.V.E.A secondary standard ionization chamber was calibrated, by a primary standard laboratory, at a determined distance. However, in the routine procedures of a calibration laboratory, sometimes the radiation detector cannot be positioned exactly at the calibration distance, for any reason. In this work, the response of a secondary standard ionization chamber was tested to verify the possibility of its use at different distances than at the calibration distance, using the same calibration factor.Artigo IPEN-doc 13447 Study of the influence of scattered radiation at a gamma irradiator2008 - AFONSO, LUCIANA C.; CALDAS, LINDA V.E.The Calibration Laboratory of IPEN offers calibration services for portable radiation monitors using a Buchler gamma irradiator with 137Cs and 60Co radioactive sources. The beam dosimetry measurements are taken periodically between the source-instrument distances of 1m and 4m. The ISO 4037 standard (International Organization for Standardization) states that the air kerma rate due to scattered radiation shall not exceed 5% of that due to direct radiation. To verify if the facility was in accordance to the requirements, the evaluation of the scattered radiation was performed in this work. The air kerma rates were measured on the beam axis at various distances from the source up to 5.5m, and the radiation attenuation curve was obtained. The air kerma rates were proportional within 5% of deviation to the inverse square law from the source centre to the detector centre, as required by the ISO 4037 standard.Artigo IPEN-doc 13383 Comparison between filters with different purities for the HVL determination of X-ray beams2008 - AFONSO, LUCIANA C.; PEREIRA, MARCO A.G.; COSTA, PAULO R.; CALDAS, LINDA V.E.Artigo IPEN-doc 13365 Characteristics of a tandem system of ionization chambers in X-ray beams mammography level2008 - AFONSO, L.C.; VIVOLO, V.; CALDAS, L.V.E.