REGINA BECK TICIANELLI
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Artigo IPEN-doc 25771 Evaluation of the uncertainty associated with sample holders in NAA measurements in LAN/IPEN2019 - ZAHN, G.S.; TICIANELLI, R.B.; SAIKI, M.; GENEZINI, F.A.In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spec-trometry in NAA measurements. This material is very practical, but its chemical composition may be troublesome, as it presents large amounts of elements with intermediate atomic number, with attenuation factors for low-energy gamma-rays that must not be neglected. In this study, count rates obtained using different sample holders were compared. To accomplish that, an Am-241 source, with 59-keV gamma emission, was used so that low-energy gamma attenuation differences can be determined. Moreover, in order to study the energy dependence of these differences, a Ho-166m source was also used. From these results, it was possible to analyze the experimental error associated to the variations between sample holders, with the aim of introducing an addictive term to the uncertainty analysis of comparative Neu-tron Activation Analysis results.Artigo IPEN-doc 23827 Long-term performance assessment of HPGE detectors used in the neutron activation analysis laboratory of IPEN-CNEN/SP (Brazil)2017 - ZAHN, G.S.; GENEZINI, F.A.; TICIANELLI, R.B.; SAIKI, M.In this work, verification data for 11 HPGe detectors from two different manufacturers and three different intrinsic configurations were analyzed in respect to the stability of both the efficiency and resolution for the 122 keV peak from 57Co and the 1332 keV peak from 60Co. The results allow a discussion about the stability of these parameters over time (in some cases, almost 15 years), their sensitivity to imminent detector failures and their performance after a failure has been corrected; moreover, the results show a clear correlation between the manufacturer or configuration and the long-term performance of the detector.Artigo IPEN-doc 20822 Can robust statistics aid in the analysis of NAA results?2015 - ZAHN, GUILHERME S.; GENEZINI, FREDERICO A.; SECCO, MARCELLO; TICIANELLI, REGINA B.; FIGUEIREDO, ANA M.G.Artigo IPEN-doc 17288 Metals and semi-metals in street soils of São Paulo city, Brazil2012 - RIBEIRO, ANDREZA P.; FIGUEIREDO, ANA M.G.; TICIANELLI, REGINA B.; NAMMOURA NETO, GEORGES M.; SILVA, NATALIA C.; KAKAZU, MAURICIO H.; ZAHN, GUILHERME