Radiative-lifetime measurements in Si II-Si V

Abstract

Radiative lifetimes have been measured for transitions in Si II to Si V in the vacuum ultraviolet region using the beam-foil technique. Lifetime results for Si II-IV transitions resolve existing discrepancies among previous measurements for these ions, and derived oscillator strengths reflect the effects of configuration interaction for several terms in Si III. The oscillator strength for the 1194 AA multiplet in Si II is the first experimental value for this transition that provides consistency with interstellar curves of growth determined recently from observations for the first time, and the first experimental lifetime results for this ion have been obtained.