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

Abstract Dielectronic recombination (DR) rate coefficients for the ground levels of low ionization state W q + ( 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 4 f , 5 p , or 5 d- shell structure ion. Core excitations Δ n c = 0 , 1 of 4 f , 5 p , and 5 d (W 5 + ), Δ n c = 2 of 4 f , and Δ n c = 0 of 4 d (W 7 + ), and 5 s (W 8 + ) are included to the total DR rate coefficient. The core excitations Δ n c = 0 , 5 p  → 5 l and Δ n c = 1 , 4 f  → 5 l 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.