Abstract
Excitation energies, radiative rates, and cross sections of tungsten ions (W38+) by electron impact have been calculated using the multiconfiguration Dirac-Fock and R-matrix methods for a configuration state list, which consists of 4 p 6 , 4 p 5 4 l , and 4 p 4 4 l 2 , l = d and f. A set of configuration state functions with double excitations up to 5l orbitals have been included within the calculations of energy levels and transition probabilities. R-matrix calculations of collision strength and cross section have been executed for the intercombination transitions between 4 p 6 , 4 p 5 4d, and 4p54f. Resonance collision strengths have been observed at low energies of incident electrons in the range of ∼5−40 Ryd; however, the strong lines limited between 12−25 Ryd. To estimate the accuracy of the calculated energy levels and transition probabilities, comparisons with experimental observations and theoretical calculations are presented, and between different methods for collision strengths and cross sections, as well.