Santos, J. P., F. Parente, S. Boucard, P. Indelicato, and J. P. Desclaux. "
X-ray energies of circular transitions and electrons screening in kaonic atoms."
Physical Review A 71 (2005): 032501.
AbstractThe QED contribution to the energies of the circular (n, = n–1), 2n13, transitions have been calculated for several kaonic atoms throughout the periodic table, using the current world-average kaon mass. Calculations were done in the framework of the Klein-Gordon equation, with finite nuclear size, finite particle size, and all-order Uelhing vacuum polarization corrections, as well as Källén and Sabry and Wichmann and Kroll corrections. These energy level values are compared with other computed values. The circular transition energies are compared with available measured and theoretical transition energies. Electron screening is evaluated using a Dirac-Fock model for the electronic part of the wave function. The effect of electronic wave-function correlation is evaluated.
Santos, J. P., F. Parente, S. Boucard, and P. Indelicato. "
X-ray energies of circular transitions in sigmonic atoms."
Nuclear Instruments and Methods in Physics Research Section B 235 (2005): 206.
AbstractEnergies of the circular (n, ℓ = n − 1) 1 less-than-or-equals, slant n less-than-or-equals, slant 20 levels have been calculated for hydrogenlike sigmonic atoms with 1 less-than-or-equals, slant Z less-than-or-equals, slant 92, using the current world average sigma mass, as well as the electronic shift in Σ− + Ne e− + nucleus systems, where Ne stands for the number of electrons. The electronic influence on sigmonic orbitals has also been investigated through the computation of the hyperfine structure and the anomalous Σ− magnetic moment effects in sigmonic Be 2p states.
Santos, J. P., M. C. Martins, A. M. Costa, P. Indelicato, and F. Parente. "
X-ray spectra emitted by Cl14+ ions in ECRIS plasmas."
Vacuum 82 (2008): 1522-1524.
AbstractWe study the contribution of the most important processes leading to the creation of excited states of Cl14+ ions from the ground configurations of Cl ions in an Electron Cyclotron Resonance Ion Source (ECRIS), which lead to the emission of K X-ray lines. Theoretical values for inner-shell excitation, K and KL ionization cross-sections, and energies and transition probabilities for the de-excitation processes are calculated in the framework of the Multi-Configuration Dirac-Fock (MCDF) method. With reasonable assumptions about the electron energy distribution, a theoretical K[alpha] X-ray spectrum is obtained, which reproduces closely a recent experimental result.
Santos, J. P., A. M. Costa, J. P. Marques, M. C. Martins, P. Indelicato, and F. Parente. "
X-ray-spectroscopy analysis of electron-cyclotron-resonance ion-source plasmas."
Physical Review A 82 (2010): 062516.
AbstractAnalysis of x-ray spectra emitted by highly charged ions in an electron-cyclotron-resonance ion source (ECRIS) may be used as a tool to estimate the charge-state distribution (CSD) in the source plasma. For that purpose, knowledge of the electron energy distribution in the plasma, as well as the most important processes leading to the creation and de-excitation of ionic excited states are needed. In this work we present a method to estimate the ion CSD in an ECRIS through the analysis of the x-ray spectra emitted by the plasma. The method is applied to the analysis of a sulfur ECRIS plasma.
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