Excitation collision strength and rate coefficient of Auq+ (q = 47, 55) ions by electron impact

The collision strength of excitation among configuration-average levels by electron impact in Auq+ (q = 47, 55) ions are computed systematically by using the quasi relativistic distorted-wave (QRDW) methods. We discuss the behavior of the collision strengths in high energy range and applicable condition of the plane-wave approximation. It is shown that the QRDW method can reproduce major relativistic effects as compared with the fully relativistic distorted wave results of Zhang and Sampson et al. In this paper the collision strength are scaled and fitted with a least-square Spline method. As a result thermal average rate coefficients in the entire range can be determined by five parameters for one transition process. We also offers some typical curves which demonstrate the variation of the collision strengths with electron energy and the variation of effective collisions strengths and rate coefficients with electron temperature. The result shows that the discrepancy of single electron excited data of eight kinds of ions around Ni-like gold is lower than 10%. This is very favorable for the average atom (AA) model which simulates dynamics process in thermal plasma