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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Experimental and theoretical cross sections for K-shell ionization of 52Te, 73Ta, and 83Bi by electrons with energies up to 100 keV
2019 - SANTOS, O.C.B.; VANIN, V.R.; MAIDANA, N.L.; MARTINS, M.N.; TABACNIKS, M.H.; RODRIGUES, C.L.; SILVA, T.F.; SANTOS, A.D.; BARROS, S.F.; GARCIA-ALVAREZ, J.A.; KOSKINAS, M.F.; FERNANDEZ-VAREA, J.M.; PINDZOLA, M.S.
In this work we present a combined experimental and theoretical study of K-shell ionization by electrons with energies close to the threshold. The ionization cross sections of the K shells of Te, Ta, and Bi atoms have been measured up to 100 keV with uncertainties ranging from 4% to 8%. In turn, calculations have been done using the subconfiguration average distorted-wave (SCADW) method, which includes the full two-body retarded electromagnetic interaction between the projectile and target electrons. The predictions of the SCADW method are in good agreement with the experimental data. In contrast, theoretical cross sections based on first-order perturbation theory where the transverse interaction is computed with plane waves instead of distorted waves underestimate the SCADW values as well as the experimental data. The difference between the two investigated ab initio formalisms grows with atomic number, being 3% for Te, 15% for Ta, and 25% for Bi. An additional comparison of both theoretical approaches with recent measurements for Au K supports the conclusion that the SCADW method reproduces well the experimental K-shell ionization cross section of atoms with intermediate to large Z near the threshold.
Ionization cross sections of the Au L subshells by electron impact from the L3 threshold to 100 keV
2018 - BARROS, SUELEN F.; VANIN, VITO R.; MAIDANA, NORA L.; MARTINS, MARCOS N.; GARCIA-ALVAREZ, JUAN A.; SANTOS, OSVALDO C.B.; RODRIGUES, CLEBER L.; KOSKINAS, MARINA F.; FERNANDEZ-VAREA, JOSE M.
We measured the cross sections for Au Lα, Lβ, Lγ, Lℓ and Lη x-ray production by the impact of electrons with energies from the L3 threshold to 100 keV using a thin Au film whose mass thickness was determined by Rutherford Backscattering Spectrometry. The x-ray spectra were acquired with a Si drift detector, which allowed to separate the components of the Lγ multiplet lines. The measured Lα, Lβ, ${\rm{L}}{\gamma }_{1}$, L${\gamma }_{\mathrm{2,3,6}}$, ${\rm{L}}{\gamma }_{\mathrm{4,4}^{\prime} }$, ${\rm{L}}{\gamma }_{5}$, ${\rm{L}}{\ell }$ and Lη x-ray production cross sections were then employed to derive Au L1, L2 and L3 subshell ionization cross sections with relative uncertainties of 8%, 7% and 7%, respectively; these figures include the uncertainties in the atomic relaxation parameters. The correction for the increase in electron path length inside the Au film was estimated by means of Monte Carlo simulations. The experimental ionization cross sections are about 10% above the state-of-the-art distorted-wave calculations.