Bragg-Surface diffraction (BSD) : high resolution microprobe to study ion implanted semiconductors / Forças de oscilador ponderadas e tempos de vida para os espectros de Si II, Si VIII e SI IX

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The principal objective of this work is to present the weighed oscillator strengths (gf) and the lifetimes for all the eletric dipole transitions experimentally known for the íons of Si II, Si VIII VIII and Si IX. The interpretation of the calculation of these two values is for instance of fundamental importance in the astrophysics, because the silicon in your several ionization degrees is one of the most common elements observed in absorption and emission spectra of astrophysical sources. In this work it is done for each one of the ions a compilation of alI the values of energy and of wavelengths for all the transitions experimentally known, with these values we calculated the lifetimes and the weigthed oscillator strengths. These calculations are accomplished in a multiconfiguration Hartree-Fock relativistic (HFR) approach. The eletrostatic parameters were optimized by a least-square procedure in order to produce a better adjustment with experimental values of energy levels. This method produces values of gf that are in better agreement with the observed intensities as well as lifetimes closer of the experimental ones. In this work we presented all the spectral lines of electric dipole known experimentally for each one of the ions that are summarized: -Silicon one time ionized, Si II, where 146 energy levels and 405 eletric dipole transitions were observed in the range 700-9500Å; -Silicon seven times ionized, Si VIII, where 73 energy levels and 96 eletric dipole transitions were observed in the range 50-1900Å and -Silicon eight times ionized, Si IX, where 56 energy levels and 103 eletric dipole transitions were observed in the range 45-450Å

ASSUNTO(S)

fisica nuclear espectroscopia atomica

ACESSO AO ARTIGO

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