Resonance Excitation Rate Coefficient of Ni-Like Tantalum

The ab initio calculations of electron-impact resonant excitation rate coefficients from the ground level to 54 fine-structure levels of 3d⁹4l(l=s,p,d,f) configurations of Ni-like tantalum ion are performed by using a fully relativistic distorted-wave approximation. The configuration-interaction effects are taken into account. The decays to autoionizing levels possibly followed by autoionization cascades are also included in the calculation. The contributions from doubly-excited intermediate states of Cu-like 3l¹⁷n'l'n''l''(n'=4,5; n''=5-15) are calculated explicitly, and the contributions from high Rydberg states (n''>15) are taken into account by using n^-3 scaling law. The present results should be more accurate than the existent calculations.