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

Abstract

Abstract In this paper we report on calculations on energy levels, radiative rates, collision strengths, and effective collision strengths for transitions among the lowest 36 levels of the n ≤ 6 configurations of H-like Fe XXVI. Flexible atomic code (FAC) is adopted for the calculation. Energy levels and radiative rates are calculated within relativistic configuration-interaction method. Direct excitation collision strength is calculated using relativistic distorted-wave approximation. Resonance contributions through the relevant He-like doubly excited n ′ l ′ n ″ l ″ configurations with n ′ ≤ 7 and n ″ ≤ 75 are explicitly taken into account using the isolated process and isolated resonances approximation. We present the radiative rates, oscillator strengths, and line strengths for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among the 36 levels. Furthermore, collision strengths and effective collision strengths are reported for all the 630 transitions among the above 36 levels over a wide energy (temperature) range up to 25 keV ( 10 9 K ) . Extensive comparisons are made with earlier available results and the accuracy of the data is assessed.