RENATO SEMMLER

RENATO SEMMLER

(Fonte: Lattes)

Resumo

Graduado em Física pela Pontifícia Universidade Católica de São Paulo (1989), Mestre em Tecnologia Nuclear pela Universidade de São Paulo (1993) e Doutor em Tecnologia Nuclear pela Universidade de São Paulo (2006). Atualmente é pesquisador da Comissão Nacional de Energia Nuclear (CNEN), lotado no Centro do Reator de Pesquisas (CERPq) do Instituto de Pesquisas Energéticas e Nucleares (IPEN). Docente da pós-graduação stricto sensu - Programa de tecnologia nuclear do IPEN - Universidade de São Paulo e da pós-graduação stricto sensu - Mestrado profissional de tecnologia das radiações na saúde. Tem experiência na área de Física Nuclear de baixas energias atuando nos seguintes temas: reações de captura de nêutrons térmicos (prompt gamma rays), método k0 de análise por ativação neutrônica, caracterização do espectro de nêutrons junto aos canais de irradiação do reator IEA-R1, espectroscopia gama, fotodesintegração, reações fotonucleares (fotofissão e fotonêutrons) e ensino de física. Professor e organizador da EAEN - Escola Avançada de Energia Nuclear para estudantes do Ensino Médio, preferencialmente envolvidos com olimpíadas de física e química: Teoria e Aplicações das Ciências Nucleares. Professor de física com mais de 25 anos de experiência em cursos universitários, pré-vestibular e ensino médio. (Texto extraído do Currículo Lattes em 27 dez. 2021)

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Re-characterization of pneumatic station irradiation position of IEA-R1 reactor for use in k0 - INAA method
2024 - FLORES, J.P.O.; SEMMLER, R.; DIAS, M.S.; KOSKINAS, M.F.; MOREIRA, D.S.; YAMAZAKI, I.M.; SILVA, P.S.C.; MAIHARA, V.A.
Python software for data processing and quality control in HPGe detectors
2024 - BERTACO, G.P.; SILVA, P.S.C.; ZAHN, G.S.; SILVA, B.F. da; SEMMLER, R.
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.
The 2021 IAEA software intercomparison for k0‑INAA
2023 - BLAAUW, MENNO; D'AGOSTINO, GIANCARLO; DI LUZIO, MARCO; DUNG, HO MANH; JACIMOVIC, RADOJKO; DIAS, MAURO da S.; SEMMLER, RENATO; VAN SLUIJS, ROBBERT; BARRADAS, NUNO P.
In order to establish the variation between results in mass fractions due to software implementation, as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (k0-IPEN, k0-INRIM, k0-DALAT, k0-IAEA and KayWin) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as intermediate results and observed mass fractions of the certified reference material BCR-320R “channel sediment” are available through the IAEA on request. The variations in concentrations attributed to differences between the programs were initially found to be 5.6 and 7.9%, for certified and uncertified concentrations, respectively. After the certified concentrations had been made available to the participants and they had been allowed to improve their programs, the variations found were 2.7 and 3.4%, respectively. The main identified remaining causes of variation are differences in the procedures used for detector efficiency characterisation and neutron spectrum parameter determination.
The 2021 IAEA software intercomparison for k0-INAA
2022 - D'AGOSTINO, GIANCARLO; BLAAUW, MENNO; DUNG, HO M.; LUZIO, MARCO di; JACIMOVIC, RADOJKO; DIAS, MAURO da S.; SEMMLER, RENATO; SLUIJS, ROBBERT van; BARRADAS, NUNO P.
In order to establish the variation between results due to software implementation in mass fractions as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (list of program names here) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as expected and certified mass fractions of the BCR-320R channel sediment sample material will be made available to all.
k0-IPEN
2022 - 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 new software package for INAA, developed at the Nuclear Metrology Laboratory (LMN) of the Nuclear and Energy Research Institute (IPEN-CNEN/SP), called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically all the tasks necessary in order to obtain the mass fractions of the irradiated samples. The goals of these nine routines are: a) to calculate the experimental peak efficiencies and P/T ratios for the standard sources, together with all the corresponding uncertainties; b) to correct the peak efficiencies for coincidence summing; c) to fit the peak efficiencies and P/T ratios with log-log polynomial functions; d) to determine experimentally the  and f parameters by the Triple Bare and by the Cd Ratio Multimonitor Methods; e) to correct for interferences; f) to determine the average mass fractions, taking into account the correlations among all partial uncertainties involved. In the present version, the only data that must be inserted as input parameter, externally from the package, are the self-shielding correction factor, which is calculated by the MATSSF code, and the geometry factor that corrects for the difference between sizes of standard sources and measured samples. The code can deal with different spectrum formats such as CHN, SPE and CNF. The routine designed to calculate the peak areas has a simple algorithm and is not yet capable of separating multiplets. Therefore, it is suitable for analysing separated peaks, such as those found in standard calibration source measurements. However, for complex spectra, the code can read peak list files obtained from other codes, such as HyperMet or HyperLab. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to regions where there are only a few experimental points available. The code k0-IPEN is being tested and its validation accomplished by means of an intercomparison sponsored by the IAEA, and presented at this conference.
Magnetic Resonance safety in the view of new Brazilian regulations
2021 - CLEMENTE, A.; SEMMLER, R.
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.
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.