Atomic data and spectral line intensities for Ar XIII

Abstract

The energy levels, oscillator strengths, spontaneous radiative decay rates, and electron impact collision strengths are calculated for Ar XIII using the recently developed Flexible Atomic Code (FAC). These data pertain to the 224 levels belonging to the following configurations: 2s 22p 2, 2s2p 3, 2p 4, 2s 22p3l, 2s2p 23l, 2s 22p4l (l = s, p, d, f), 2s 22p5s, 2s 22p5p, and 2s 22p5d. Effective collision strengths are obtained at five electron temperatures: log T e (K) = 5.0, 5.5, 6.0, 6.5, and 7.0 by integrating the collision strengths over a Maxwellian electron distribution. These atomic data are generated to support the interpretation of astrophysical objects as well as fusion plasmas, which frequently contain emission lines from Ar XIII. This work supplements previous work published by Bhatia by extending the calculation of effective collision strengths and radiative decay rates to n = 5 configurations. Level populations and spectral line intensities are obtained by solving the rate equations of the 224 energy levels at densities of 10 8, 10 9, 10 10, 10 11, and 10 12 cm −3 and a temperature of 2.51 × 10 6 K. This temperature is typical for Ar XIII when formed at equilibrium by collisional ionization and recombination.