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Papers by Adela Consuela Scafes

Research paper thumbnail of ERDA at the 9 MV Tandem and at the 3 MV Tandetron of IFIN-HH

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Sep 1, 2017

Recoil spectrometry using heavy ions proposed in 1976 by L'Ecuyer has evolved into a universal IB... more Recoil spectrometry using heavy ions proposed in 1976 by L'Ecuyer has evolved into a universal IBA technique. Few years later an experimental setup for simultaneous light and medium heavy element detection including a compact DE(gas)-E r (solid) telescope, was developed at the Tandem accelerator of IFIN-HH. To increase the resolution, an integrated preamplifier was mounted close to the ionization chamber. The calibration procedure for the telescope and the software for the quantitative evaluation of the data are briefly presented. Recently, a 3 MV Tandetron accelerator has been installed and commissioned at the IFIN-HH. Among several ion-beam techniques for detection and depth profiling of hydrogen isotopes, Elastic Recoil Detection Analysis (ERDA) technique using a low energy 4 He beam, proposed by Doyle and Peercy, is particularly advantageous. By measuring simultaneously both the H or D recoiling at a forward angle and backscattered 4 He ions, a rather complete characterization of the sample can be achieved. Selected results from our investigations, obtained using these facilities, are presented.

Research paper thumbnail of Potential of the Bucharest 3 MV Tandetron™ for IBA studies of deer antler mineralization

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2016

Research paper thumbnail of Combined PIXE and optical microscopy characterization of calcium compounds in dental calculus

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Jul 1, 2021

Abstract A combined PIXE and optical microscopy approach was applied to examine the dental calcul... more Abstract A combined PIXE and optical microscopy approach was applied to examine the dental calculus of patients with periodontal disease. PIXE was performed with the Bucharest 3 MV Tandetron with 3 MeV protons and a HPGe detector, using hydroxyapatite (HA) and other standards. Sections 30 µm thick were prepared and observed using polarization microscopy and histochemical techniques. Both methods revealed the heterogeneous nature of dental calculus. Two main types (I and II) were postulated based on Ca/P ratios (p

Research paper thumbnail of Excitation function measurements of the elastic and inelastic scattering of protons in the 1600 to 5300 keV energy range for Li and F

The European Physical Journal A

Research paper thumbnail of Relativistic light-shift theory of few-electron systems: Heliumlike highly charged ions

Physical Review A, 2017

The light-shift theory of many-electron systems in a laser field is described using the projectio... more The light-shift theory of many-electron systems in a laser field is described using the projection operators technique. In heavy ions, the electrons are tightly bound by the Coulomb potential of the nucleus, which prohibits ionization even by strong lasers. However, interaction with the monofrequent laser field leads to dynamic shifts of the electronic energy levels, and the process is treated by second-order time-dependent perturbation theory. In order to treat heliumlike systems, one decomposes the corresponding matrix elements into hydrogenlike matrix elements using the independent particle model. We are applying a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the Stark long-wavelength dipole approximation and takes into account nondipole effects of retardation and interaction with the magnetic field components of the laser beam.

Research paper thumbnail of PIXE and PIGE assessment of in vivo elemental and physical changes of a composite from a dental filling

X-Ray Spectrometry

Simultaneous particle-induced x-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE... more Simultaneous particle-induced x-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) measurements in the 0–270 keV range with a low-energy hyperpure Ge detector have been performed on the outer surface and on an inner section of a dental composite filling extracted from a patient. The biomaterial has been identified as the fluorine-releasing Tetric Ceram dental composite. Compared to the native material, the dental filling evidenced changes occurring during the in vivo oral use. These included mainly Cl and K accumulation and loss of Zr, Ba, Yb (by PIXE), and F (in the PIGE region). The changes were similar at the surface and inside of the dental filling for most of the above elements, indicating an unexpectedly high permeability of the material, maybe due to microscopic bulk fracture of the dental composite filling throughout its use. The PIGE spectra detected also Al and traces of Hf and Sm possibly associated with Zr and Yb. Changes in the ratio of the L lines of Yb...

Research paper thumbnail of ERDA at the 9 MV Tandem and at the 3 MV Tandetron of IFIN-HH

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Sep 1, 2017

Recoil spectrometry using heavy ions proposed in 1976 by L'Ecuyer has evolved into a universal IB... more Recoil spectrometry using heavy ions proposed in 1976 by L'Ecuyer has evolved into a universal IBA technique. Few years later an experimental setup for simultaneous light and medium heavy element detection including a compact DE(gas)-E r (solid) telescope, was developed at the Tandem accelerator of IFIN-HH. To increase the resolution, an integrated preamplifier was mounted close to the ionization chamber. The calibration procedure for the telescope and the software for the quantitative evaluation of the data are briefly presented. Recently, a 3 MV Tandetron accelerator has been installed and commissioned at the IFIN-HH. Among several ion-beam techniques for detection and depth profiling of hydrogen isotopes, Elastic Recoil Detection Analysis (ERDA) technique using a low energy 4 He beam, proposed by Doyle and Peercy, is particularly advantageous. By measuring simultaneously both the H or D recoiling at a forward angle and backscattered 4 He ions, a rather complete characterization of the sample can be achieved. Selected results from our investigations, obtained using these facilities, are presented.

Research paper thumbnail of Potential of the Bucharest 3 MV Tandetron™ for IBA studies of deer antler mineralization

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2016

Research paper thumbnail of Combined PIXE and optical microscopy characterization of calcium compounds in dental calculus

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Jul 1, 2021

Abstract A combined PIXE and optical microscopy approach was applied to examine the dental calcul... more Abstract A combined PIXE and optical microscopy approach was applied to examine the dental calculus of patients with periodontal disease. PIXE was performed with the Bucharest 3 MV Tandetron with 3 MeV protons and a HPGe detector, using hydroxyapatite (HA) and other standards. Sections 30 µm thick were prepared and observed using polarization microscopy and histochemical techniques. Both methods revealed the heterogeneous nature of dental calculus. Two main types (I and II) were postulated based on Ca/P ratios (p

Research paper thumbnail of Excitation function measurements of the elastic and inelastic scattering of protons in the 1600 to 5300 keV energy range for Li and F

The European Physical Journal A

Research paper thumbnail of Relativistic light-shift theory of few-electron systems: Heliumlike highly charged ions

Physical Review A, 2017

The light-shift theory of many-electron systems in a laser field is described using the projectio... more The light-shift theory of many-electron systems in a laser field is described using the projection operators technique. In heavy ions, the electrons are tightly bound by the Coulomb potential of the nucleus, which prohibits ionization even by strong lasers. However, interaction with the monofrequent laser field leads to dynamic shifts of the electronic energy levels, and the process is treated by second-order time-dependent perturbation theory. In order to treat heliumlike systems, one decomposes the corresponding matrix elements into hydrogenlike matrix elements using the independent particle model. We are applying a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the Stark long-wavelength dipole approximation and takes into account nondipole effects of retardation and interaction with the magnetic field components of the laser beam.

Research paper thumbnail of PIXE and PIGE assessment of in vivo elemental and physical changes of a composite from a dental filling

X-Ray Spectrometry

Simultaneous particle-induced x-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE... more Simultaneous particle-induced x-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) measurements in the 0–270 keV range with a low-energy hyperpure Ge detector have been performed on the outer surface and on an inner section of a dental composite filling extracted from a patient. The biomaterial has been identified as the fluorine-releasing Tetric Ceram dental composite. Compared to the native material, the dental filling evidenced changes occurring during the in vivo oral use. These included mainly Cl and K accumulation and loss of Zr, Ba, Yb (by PIXE), and F (in the PIGE region). The changes were similar at the surface and inside of the dental filling for most of the above elements, indicating an unexpectedly high permeability of the material, maybe due to microscopic bulk fracture of the dental composite filling throughout its use. The PIGE spectra detected also Al and traces of Hf and Sm possibly associated with Zr and Yb. Changes in the ratio of the L lines of Yb...