Electron impact excitation of Fe XVI: radiative and excitation rates

Abstract

Aims. In this paper we report calculations for energy levels, radiative rates, collision strengths, and effective collision strengths for transitions in Fe XVI. Methods. For energy levels and radiative rates we have used the General purpose Relativistic Atomic Structure Package (GRASP), and for the compuations of collision strengths the Dirac Atomic R-matrix Code (DARC) has been adopted. Results. Energies for the lowest 39 levels among the n < 7 (l ≤ 4) configurations of Fe XVI are reported. Additionally, radiative rates, oscillator strengths, and line strengths are reported for all electric dipole (El), magnetic dipole (Ml), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among these levels. Electron impact excitation collision strengths have also been calculated for all 741 transitions among the above 39 levels over a wide energy range up to 220 Ryd. Resonances have been resolved in the threshold region, and effective collision strengths have been obtained over a wide temperature range up to 10 7 K. Comparisons are made with the available results in the literature, and the accuracy of the present results is assessed.