Relativistic-configuration-interaction calculations of K alpha satellite properties for aluminum plasmas created by intense proton beams.

Abstract

Configuration-interaction calculations with Breit-Pauli relativistic corrections have been carried out for aluminum ions for the purpose of studying K\ensuremath{\alpha} satellite spectra obtained during intense proton-beam--plasma interaction experiments. We present results for calculated wavelengths, oscillator strengths, and fluorescence yields of K\ensuremath{\alpha} satellites for Al i--Al xi . Detailed calculations have been performed both for transitions involving levels of ground-state configurations and for transitions involving levels of low-lying excited configurations with M-shell spectator electrons. Calculated wavelengths for the K\ensuremath{\alpha} transitions are compared with a spectrum obtained during a Particle Beam Fusion Accelerator II proton-beam experiment [Lasers Part. Beams 8, 555 (1990)] at Sandia National Laboratories. Our calculations show that the K\ensuremath{\alpha} satellite lines of aluminum ions can be classified into two distinct groups: one involving transitions of type 1${\mathit{s}}^{1}$2${\mathit{s}}^{\mathit{r}}$2${\mathit{p}}^{\mathit{q}}$\ensuremath{\rightarrow}1${\mathit{s}}^{2}$2${\mathit{s}}^{\mathit{r}}$2${\mathit{p}}^{\mathit{q}\mathrm{\ensuremath{-}}1}$, the other 1${\mathit{s}}^{1}$2${\mathit{s}}^{\mathit{r}}$2${\mathit{p}}^{\mathit{q}\mathrm{\ensuremath{-}}1}$3l\ensuremath{\rightarrow}1${\mathit{s}}^{2}$2${\mathit{s}}^{\mathit{r}}$2${\mathit{p}}^{\mathit{q}\mathrm{\ensuremath{-}}2}$3l. The former consists of the resonance K\ensuremath{\alpha} transitions, which gives the characteristic satellite-line position of an ion, while the latter overlaps with the resonance K\ensuremath{\alpha} lines of the next-higher ionization stage. We find that both correlation effects and relativistic corrections significantly impact the calculated K\ensuremath{\alpha} transition energies.