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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Standartization of (166m)Ho in a coincidence system by software and determination of its gamma emission probabilities
2019 - CARVALHO, ANA C.R. de; MOREIRA, DENISE S.; KOSKINAS, MARINA F.; DIAS, MAURO da S.
This works presents a new standardization of the radionuclide (166m)Ho that was carried out at Nuclear Metrology Laboratory (LMN) at IPEN. (166m)Ho decays with 1133 years of half-life by beta emission followed by a cascade of gamma-rays in a range of 73 to 1427 keV, and these characteristics makes it a good secondary standard to the calibration of gamma spectrometers. Previously calibrated with a standard 4 Pi(PC)Beta-Gama coincidence system, the same samples were now measured in the Software Coincidence System (SCS), where the data analyses can be done after the measurements, using a software developed at LMN as well. The SCS is composed of a 4Pi geometry proportional counter operated at 0.1MPa coupled to one NaI(Tl) crystal, positioned above the PC counter, and to a HPGe detector, positioned below the PC counter. The signals from all detectors are digitalized and their pulses height and time of occurrence are recorded on computer files. After the standardization, the emission probabilities per decay of the most intense gamma-rays in the (166m)Ho decay were determined by means of a HPGe spectrometer system, which was calibrated with standard sources previously calibrated in the 4 Pi(PC)Beta-Gama coincidence system, and the results were compared with the literature. All the uncertainties were treated by the covariance analysis method.
Preliminary study of radionuclide standardization by TDCR method applying a time-to-amplitude converter
2019 - MORAIS, THALES S.L. de; KOSKINAS, MARINA F.; MOREIRA, DENISE S.; DIAS, MAURO da S.
This paper proposes an alternative to the use of counters for the standardization of radionuclides in a 3-photodetectors liquid scintillation counter by the triple to double coincidence ratio (TDCR) method using an electronic system for processing pulses that allows the subtraction of the accidental coincidences. The electronic system consists of ampli ers, discriminators, logic gates and delay modules feeding a time-to-amplitude converter (TAC) with output to a multichannel analyzer (MCA). This system does not require individual counters for each photodetector and coincident counts contribute to the noise reduction. The method compares 3 di erent TAC spectra registered in MCA with 4, 3 or 2 peaks obtained from di erent con gurations of the electronic system. For testing the system, a series of measurements with a 90Sr standard solution was performed.
Preliminary measurements using a Triple to Double Coincidence Ratio (TDCR) Liquid Scintillator Counter System
2019 - KOSKINAS, MARINA F.; KUZNETSOVA, MARIA; MOREIRA, DENISE S.; SCHOUERI, ROBERTO M.; MORAIS, THALES S.L. de; SEMMLER, RENATO; DIAS, MAURO da S.
The preliminary measurements using a Triple to Double Coincidence Ratio (TDCR) Liquid Scintillator Counter System developed by the Nuclear Metrology Laboratory (LMN) at IPEN, is presented. The TDCR system makes use of three photomultipliers positioned at 120° relative angle, operating in coincidence. For this preliminary measurement, 14C was selected to be standardized. This solution was previously calibrated by the efficiency tracing technique using a  (PC) coincidence system, employing 60Co as a tracer. 14C was chosen due to be a beta pure emitter with low end-point energy of 156 keV. The Software Coincidence System (SCS) developed by the LMN was used for both systems to register the events. MICELLE 2 code was used to calculate the theoretical TDCR efficiency. Measurements using HIDEX, a commercial liquid scintillator system, were also carried out and the results from the three methods were compared, showing a good agreement.
Gamma-ray impurities of 111In, 201Tl, 177Lu and 99mTc determined by means of a HPGE spectrometer
2017 - KOSKINAS, MARINA F.; ALMEIDA, JAMILLE da S.; MOREIRA, DENISE S.; SEMMLER, RENATO; DIAS, MAURO da S.
This work aims to present the radioactive impurities gamma rays emitters detected in some radiopharmaceuticals widely applied to diagnosis and therapy purposes, supplied to nuclear medicine services in Brazil by the Radiopharmaceutical Center(CR) of Nuclear and Energy Research Institute, IPEN, in São Paulo. The analysis was undertaken by means of an HPGe gamma spectrometer. The radiopharceuticals analyzed were: 111In, 201Tl, 177Lu and 99mTc.
Primary standardization of 90Sr-90Y radioactive solution
2017 - KOSKINAS, MARINA F.; MARQUES, CAIO P.; MOREIRA, DENISE S.; RAJPUT, MUHAMMAD U.; YAMAZAKI, IONE M.; DIAS, MAURO S.
In the present work, the procedure developed by the Nuclear Metrology Laboratory (LMN) at IPEN, for the primary standardization of 90Sr-90Y, is presented. The method applied has been the efficiency tracing technique using a  coincidence system. That consists in the measurement of a beta pure emitter along with a beta-gamma emitter, previously standardized, which will provide the beta efficiency. In this work, the beta-gamma emitter used was 60Co. The beta efficiency has varied using external absorbers, and the specific activity was determined using the extrapolation curve. ESQUEMA Code, which predicts the extrapolation curve by means of Monte Carlo technique, was applied, and the specific activity obtained from Monte Carlo simulation was compared with the experimental, showing good agreement within the experimental uncertainties.
Preliminary measurements of k0 values for W-186
2017 - BARROS, LIVIA F.; DIAS, MAURO S.; KOSKINAS, MARINA F.; YAMAZAKI, IONE M.; SEMMLER, RENATO
There are various methods of neutron activation analysis, one of these is the k0 Method for quantitative reactor Neutron Activation Analysis (NAA). The k0-NAA procedure is nowadays widely used in numerous laboratories performing NAA all over the world. Among these reactions, 186W(n, )187W can be considered important because it can be used for a W concentration measurements. The irradiations were performed at position 24A, near the core of the IEA-R1 4.5 MW swimming-pool nuclear research reactor of the Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP – Nuclear and Energy Research Institute), in São Paulo, Brazil. Two irradiations were carried out in sequence, using two sets of samples: the first with a cadmium cover around the samples and the second without, in a total of three data sets with and without Cd cover performed in 2014 and 2015. The activity measurements were carried out in an HPGe gamma-ray spectrometer. Standard sources of 152Eu, 133Ba, 60Co and 137Cs supplied by the IAEA were used in order to obtain the HPGe gamma-ray peak efficiency as a function of the energy. The covariance matrix methodology was applied to all uncertainties involved. The preliminary values of k0 for 186W(n, )187W reaction for the gamma transition energy of 479.53 keV was 3.17x10-2(5), for 618.77 keV was 9.08x10-3(15) and for 685.77 keV was 3.88x10-2(6). These preliminary values for k0 have been compared with the literature.
Impurity determination in 153Sm by means of a High Purity Germanium spectrometer
2016 - ALMEIDA, JAMILLE da S.; KOSKINAS, MARINA F.; MARQUES, CAIO P.; MOREIRA, DENISE S.; DIAS, MAURO da S.
Neste trabalho, a impureza radionuclídica de longa duração 152Eu, presente na solução de 153Sm, foi medida por meio de um espectrômetro de HPGe, calibrado na faixa de energia entre 81 e 1408 keV por meio de soluções padronizadas em ampolas seladas de 60Co, 133Ba, 137Cs e 152Eu. A razão entre as atividades do 152Eu e do 153Sm resultou 5,2x10-6. Este valor é menor que o limite estabelecido pelo controle de qualidade.
Standardization of 32P radioactive solution
2016 - MARQUES, CAIO P.; KOSKINAS, MARINA F.; ALMEIDA, JAMILLE da S.; YAMAZAKI, IONE M.; DIAS, MAURO da S.
The standardization of 32P radioactive solution using three different methods is presented. The disintegration rate was determined by the CIEMAT/NIST and TDCR methods in liquid scintillator systems and self-absorption extrapolation method using PC) system. The results obtained for the activity of the 32P solution were compared and they agree within the experimental uncertainties.
Disintegration rate and gamma ray probability per decay measurement of 166mHo
2010 - MOREIRA, D.S.; KOSKINAS, M.F.; DIAS, M.S.; TAKEDA, M.N.
Determination of ksub(0) for sup(63)Cu(n,'gamma')sup(64)Cu reaction with covariance analysis
2015 - BARROS, LIVIA F.; DIAS, MAURO S.; KOSKINAS, MARINA F.; YAMAZAKI, IONE M.; SEMMLER, RENATO