REGINA BECK TICIANELLI

REGINA BECK TICIANELLI

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Análise dos radionuclídeos encontrados na água do reator IEA-R1
2022 - ZAHN, GUILHERME S.; TICIANELLI, REGINA B.; SILVA, PAULO S.C. da; GENEZINI, FREDERICO A.
O reator IEA-R1 é do tipo piscina aberta, construído nos anos 1950. Nos últimos anos, ele opera a 4,5MW por oito horas às segundas, terças e quartas. Em todo dia de operação, duas amostras da água do reator são retiradas, uma antes de o reator ser ligado pela manhã e outra em torno das 16h, próximo ao final as operação. Essas amostras são contadas em um detector HPGe por 1500 s para verificar possíveis problemas com os elementos combustíveis, entre outros. Neste trabalho, os resultados obtidos nessas análises ao longo de alguns meses de 2019 são discutidos em termos dos radionuclídeos encontrados, bem como da dependência da sua atividade com o tempo.
Radionuclide analysis of the IEA-R1 pool water
2019 - TICIANELLI, REGINA B.; ZAHN, GUILHERME S.; SILVA, PAULO S.C. da; GENEZINI, FREDERICO A.
IEA-R1 is a 5MW pool-type research reactor built in the late 1950's. In the last years, it operates at 4.5MW for 8h on Mondays, Tuesdays and Wednesdays. In every day of operation, a sample is taken from the pool water both before starting the reactor and at the end of the day and analyzed in an HPGe detector, in order to verify for possible problems with the fuel elements or other issues. In this work, the results obtained in these analyses spanning for some months are discussed regarding the radionuclides frequently identi ed and the dependence of their activities with time.
Evaluation of the uncertainty associated with sample holders in NAA measurements in LAN/IPEN
2019 - 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.
Evaluation of the uncertainty associated with sample holders in NAA measurements in LAN/IPEN
2017 - ZAHN, GUILHERME S.; TICIANELLI, REGINA B.; SAIKI, MITIKO; GENEZINI, FREDERICO A.
In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spectrometry 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 Neutron Activation Analysis results.
Long-term performance assessment of hpge detectors used in the neutron activation analysis (LAN) of IPEN-CNEN/SP (Brazil)
2016 - ZAHN, GUILHERME S.; GENEZINI, FREDERICO A.; TICIANELLI, REGINA B.; SAIKI, MITIKO
In nuclear spectroscopy measurements, the performance of the radiation detectors employed is a key issue in the final results; moreover, in comparative measurements, the results depend on the stability of the detector between measurements, so that the detector’s efficiency can be effectively ruled out of the equation. Due to the relevance of the detectors' performances, LAN-IPEN have been performing daily verification measurements in its operational detectors since 1999; this verification consists in the measurement of composite 57+60Co sources, in which the position, resolution and CPS (counts per second) for the 122 keV peak of 57Co and the 1332 keV peak of 60Co are registered, along with the date and time of the measurement. In this work, verification data for 11 HPGe detectors from two different makers and three different intrinsic configurations were analyzed in respect to the efficiency stability (determined by the arbitrary efficiency calculated by correcting the CPS for the isotope's decay) and resolution for both peaks, as well as the ratio between the efficiencies for 122 keV and 1332 keV. The results allow a discussion about the stability of these parameters over time (in some cases, more than 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 maker or configuration and the long-term performance of the detector.
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.
Uncertainty analysis in comparative NAA applied to geological and biological matrices
2015 - ZAHN, GUILHERME S.; TICIANELLI, REGINA B.; LANGE, CAMILA N.; FAVARO, DEBORAH I.T.; FIGUEIREDO, ANA M.G.
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.
Long-term performance assessment of HPGE detectors used in the neutron activation analysis (LAN) of IPEN-CNEN/SP (Brazil)
2014 - ZAHN, GUILHERME S.; GENEZINI, FREDERICO A.; TICIANELLI, REGINA B.; SAIKI, MITIKO
Enhancing NAA results by using robust statistics
2014 - ZAHN, GUILHERME S.; GENEZINI, FREDERICO A.; SECCO, MARCELLO; TICIANELLI, REGINA B.; FIGUEIREDO, ANA M.G.