DENISE SIMÕES MOREIRA
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Artigo IPEN-doc 29835 Primary standardization and Monte Carlo modeling of ( 243Am + 239Np) by means of a 4π(PC)-γ coincidence counting system2023 - 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.Artigo IPEN-doc 29810 k0‑IPEN2023 - 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. deA 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.Artigo IPEN-doc 27118 Primary standardization and determination of gamma ray emission intensities of Ho-1662020 - 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.