Theoretical study on electron impact excitation of highly charged Ne-like ions

The electron impact excitation （EIE） cross sections from the ground state to all of the 2s 2 2p 5 3 and 2s2p 6 3（=s, p, d） states along the Ne-like isoelectronic sequence of ions （ Z =50—57） have been calculated by using the multi-configuration Dirac-Fock package GRASP92 and the fully relativistic distorted-wave program REIE06. In the calculations, the relativistic effects and electron correlation effects are considered systematically. Based on those calculations, the EIE cross sections along the Ne-like isoelectronic sequence of ions for different incident electron energies are discussed, and some important conclusions are drawn. We also study the influence of the correlation effects on the values of the 3C/3D line-intensity ratio ［3C: （2p 1/2 3d 3/2 ） 1 →2s 2 2p 6 1 S 0 , 3D: （2p 3/2 3d 5/2 ） 1 →2s 2 2p 6 1 S 0 ］ along the Ne-like sequence. A comparison is made between the present results and previous theoretical calculations and experimental results for the EIE cross sections in Ba46+ ions, and a good agreement is obtained.