EXCITATION-AUTOIONIZATION CROSS-SECTIONS AND RATE COEFFICIENTS OF CU-LIKE IONS

Detailed level-by-level calculations of the excitation-autoionization (EA) cross sections and rate coefficients were performed using the rel ativistic distorted-wave method along the Cu isoelectronic sequence fo r all the elements with 34 less than or equal to Z less than or equal to 92. While in a previous work only the 3d-4l inner-shell collisional excitations had been taken into account, the present extensive calcul ations include the 3d(10)4s-3d(9)4snl (n=4-7 and l=0-n-1) and the 3p(6 )3d(10)4s-3p(5)3d(10)4snl (n=4,5 and l=0-n-1) excitations. An extrapol ation method is used to evaluate the contribution for higher principal quantum numbers. Configuration mixing and secondary autoionization pr ocesses following radiative decay from autoionizing levels are also in cluded. The results show that the EA processes give a dominant contrib ution compared to direct ionization, up to a factor of about 15 at 2=4 3. The additional inner-shell excitations for Z<55 produce an increase in the EA effect varying from 20% to a factor of 2, with respect to t he previously predicted 3d-4l EA rates. The additional excitations are the most significant for heavy elements with Z>55, since they open EA channels, resulting in an EA rate varying typically along the sequenc e from 3 to 1 times the direct ionization rate.