Dielectronic recombination of lowly charged tungsten ions Wq+(q=5−10)

Dielectronic recombination (DR) rate coefficients for the ground levels of low ionization state Wq+ (q=5−10) ions have been obtained by an ab-inito level-by-level calculation using the flexible atomic code (FAC) based on relativistic jj coupling scheme and independent process, isolated resonance, distorted wave approximation. The radiative transition calculation in the original FAC has been adapted into parallel programming for time effective dealing with so many resonance levels of the complex open 4f, 5p, or 5d-shell structure ion. Core excitations Δnc=0,1 of 4f, 5p, and 5d (W5+), Δnc=2 of 4f, and Δnc=0 of 4d (W7+), and 5s (W8+) are included to the total DR rate coefficient. The core excitations Δnc=0, 5p → 5l and Δnc=1, 4f → 5l mainly contribute to the total DR rate coefficients. The strong resonances involved in the DR are analyzed and the total DR rate coefficients are compared with available previous ab-initio predictions and with ADAS data by a simple semiempirical formula.