MARINA FALLONE KOSKINAS

MARINA FALLONE KOSKINAS

(Fonte: Lattes)

Resumo

Graduate at Física from Pontifícia Universidade Católica de São Paulo (1972), master's at Nuclear Engineering from Universidade de São Paulo (1978) and ph.d. at Nuclear Engineering from Universidade de São Paulo (1988). Has experience in Nuclear Engineering, focusing on Instrumentation for Measure and Control of Radiation, acting on the following subjects: radionuclide metrology, standardizations in coincidence system, determination of nuclear parameters, gamma emission probability per decay. (Text obtained from the Currículo Lattes on November 17th 2021)

Possui graduação em Física pela Pontifícia Universidade Católica de São Paulo (1972), mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1978) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (1988). Atualmente é pesquisador titular do Instituto de Pesquisas Energéticas e Nucleares. Tem experiência na área de Engenharia Nuclear, com ênfase em Instrumentação para Medida e Controle de Radiação, atuando principalmente nos seguintes temas: metrologia de radionuclídeos, padronização em sistemas de coincidências, determinação de parâmetros nucleares como probabilidade de emissão gama por decaimento. (Texto extraído do Currículo Lattes em 17 nov. 2021)

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Primary standardization and Monte Carlo modeling of ( 243Am + 239Np) by means of a 4π(PC)-γ coincidence counting system
2023 - KOSKINAS, MARINA F.; MOREIRA, DENISE S.; YAMAZAKI, IONE M.; COLONNO, MARCELO; SEMMLER, RENATO; MORAIS, THALES S.L.; DIAS, MAURO S.
The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN for the primary standardization of a ( 243Am + 239Np) solution, in secular equilibrium, is described. The measurement was carried out in a 4π(PC) (α,β)− γ coincidence system. The total activity per unit mass of the solution was determined by the extrapolation technique, using a software coincidence counting systsem. The extrapolation curves were compared with Monte Carlo calculations by means of Code ESQUEMA, used in previous works, which, was improved and applied in order to calculate the alpha, beta, gamma, X-rays and coincidence spectra.
k0‑IPEN
2023 - DIAS, MAURO da S.; SEMMLER, RENATO; KOSKINAS, MARINA F.; MOREIRA, DENISE S.; YAMAZAKI, IONE M.; BRANCACCIO, FRANCO; BARROS, LIVIA F.; RIBEIRO, RAFAEL V.; MORAIS, THALES S.L. de
A software package for INAA (Instrumental Neutron Activation Analysis), developed at the Nuclear Metrology Laboratory of the IPEN-CNEN/SP, called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically most of the tasks necessary in order to obtain the mass fractions of the irradiated samples. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to source to detector distances where only a few experimental points are available. Covariance analysis was used in all steps of the calculation. The validation of the code was tested in an intercomparison sponsored by the IAEA.
Experimental determination of k0 and Q0 values for 121Sb, 123Sb and 130Ba targets applying covariance analysis
2022 - BARROS, L.F.; DIAS, M.S.; KOSKINAS, M.F.
This work consists of an experimental determination of k0 and Q0 for 121Sb, 123Sb and 130Ba targets. Covariance analysis has been introduced to supply not only the overall uncertainties in these parameters but also their correlations. The irradiations were performed near the core of the IEA-R1 4.5 MW swimming-pool nuclear research reactor of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), in São Paulo, Brazil. The epithermal neutron flux shape parameter, alpha, at the irradiation position is very close to zero, which favors to obtain Q0 values more accurately. Two irradiations were carried out in sequence, using two sets of samples: the first with bare samples and the second inside a Cd cover. The activity measurements were carried out in a previously calibrated HPGe gamma-ray spectrometer. The measurements were corrected for: saturation, decay time, cascade summing, geometry, self-attenuation, measuring time and mass. Standard sources of 152Eu, 133Ba, 60Co and 137Cs traceable to a 4πβ−γ primary system were used to obtain the HPGe gamma-ray peak efficiency as a function of the energy. The experimental efficiency curve was performed by a fourth-degree polynomial fit, in the energy range of the standard sources, 121–1408 keV, it contains all correlations between points. For energies above 1408 keV, the efficiencies were obtained by the Monte Carlo Method. The covariance matrix methodology was applied to all uncertainties involved. The final values for k0 and Q0 were compared with the literature.
Primary standardization and determination of gamma ray emission intensities of Ho-166
2020 - YAMAZAKI, I.M.; KOSKINAS, M.F.; MOREIRA, D.S.; SEMMLER, R.; BRANCACCIO, F.; DIAS, M.S.
The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN-CNEN/SP, in S~ao Paulo, for the primary standardization of 166Ho is described. The activity of 166Ho was determined by the efficiency extrapolation technique applied to a 4πβ(PC)-γ coincidence system using a gas flow proportional counter in 4π geometry coupled to a 76 x 76 mm NaI(Tl) crystal. The results for the γ-rays intensities at 80.57 and 1379.45 keV were 0.0651(11) and 0.00904(11), respectively.
Data analysis software package for radionuclide standardization with a digital coincidence counting system
2020 - BRANCACCIO, F.; DIAS, M.S.; KOSKINAS, M.F.; MOREIRA, D.S.; TOLEDO, F. de
The Nuclear Metrology Laboratory (LMN) – IPEN, S~ao Paulo, Brazil – developed a Digital Coincidence System (DCS), based on the Coincidence Counting Methodology, in order to improve its capabilities in radionuclide primary-standardization. Digital process is implemented in two steps: data-acquisition (a set of measurements) and offline software data-analysis and calculation. The present work shows the basics of the data-acquisition unit (Software Coincidence System – SCS), describes the DCS’ data-analysis process and the initial approaches chosen for the implementation of the software package (Coincidence Analyzing Task – CAT). 152Eu standardization, performed for DCS testing, software expansion and validation, is briefly discussed.
Consistency test of coincidence-summing calculation methods for extended sources
2020 - SIMA, O.; DE VISMES OTT, A.; DIAS, M.S.; DRYAK, P.; FERREUX, L.; GURAU, D.; HURTADO, S.; JODLOWSKI, P.; KARFOPOULOS, K.; KOSKINAS, M.F.; LAUBENSTEIN, M.; LEE, Y.K.; LEPY, M.C.; LUCA, A.; MENEZES, M.O.; MOREIRA, D.S.; NIKOLIC, J.; PEYRES, V.; SAGANOWSKI, P.; SAVVA, M.I.; SEMMLER, R.; SOLC, J.; THANH, T.T.; TYMINSKA, K.; TYMINSKI, Z.; VIDMAR, T.; VUKANAC, I.; YUCEL, H.
An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.