Energy Levels and Radiative Rates for Li-like Ar XVI and Fe XXIV

Abstract

Energy levels for transitions among the lowest 24 fine-structure levels belonging to the 1s2nl (n ≥ 5) configurations of Li-like Ar XVI and Fe XXIV have been calculated using the fully relativistic GRASP code. Oscillator strengths, radiative rates and line strengths have also been generated among these levels for the four types of transitions: electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2). Comparisons are made for the electric dipole transitions with other available results, and the accuracy of the present data is assessed.

Energy levels and radiative rates for transitions in Ar XIII, Ar XIV and Ar XV

“…Therefore, with this in view we report in this paper our results of energy levels, radiative rates (A-values), oscillator strengths ( f -values) and line strengths (S -values) and Ar XV. Similar results for Ar XVI have already been reported by McKeown et al (2004), whereas calculations are in progress for some other ions, such as Ar XVII and Ar XVIII.…”

“…However the accuracy achieved is often poor, especially for transitions among the degenerate levels of a state, because the relativistic effects are not properly accounted, and two-body operators are completely neglected. An inadequacy of this method has been discussed in detail by Hibbert (2003), and has been demonstrated for results in Fe XIII by Young (2004), in Fe XVII by Nahar et al (2003), and in Fe XXIV by McKeown et al (2004). We will further discuss below the accuracy of their energy levels in comparison to other available calculations.…”

Radiative rates and electron impact excitation rates for H-like Fe XXVI

“…This is in continuation of our work on generating atomic data (energy levels, radiative rates, collision strengths, and excitation rates) for iron ions, for which we have already reported our calculations for Fe ix , Fe x (Aggarwal & Keenan 2004b, 2005b, Fe xi (Aggarwal & Keenan 2003a,b), Fe xiii (Aggarwal & Keenan 2004a,b), Fe xv , Fe xvi , 2007, Fe xvii , Fe xviii (Jonauskas et al 2004), Fe xxi (Aggarwal & Keenan 1999, and Fe xxiv (McKeown et al 2004). In this paper we report similar results for transitions in Fe xxvi.…”

Effective collision strengths for transitions in Fe X

“…To analyse the vast amount of observational data available from space missions such as SOHO, Chandra and XMM Newton, theoretical atomic data for Fe ions are required, because there is paucity of desired experimental results. To this end we have also reported atomic data (namely, energy levels, radiative rates, collision strengths and excitation rate coefficients) for Fe XI (Aggarwal & Keenan 2003a,b), Fe XIII (Aggarwal & Keenan 2004a, Fe XV (Aggarwal et al 2000, Fe XVII , Fe XVIII (Jonauskas et al 2004), Fe XXI , and Fe XXIV (McKeown et al 2004), and in this paper we present our results of Ω and Υ for transitions in Fe X.…”