We report on the projectile energy dependence of the cross sections for producing K Auger electrons in 2–170-keV ${\mathrm{N}}^{7+}+\mathrm{N}\mathrm{e}$ collisions. The present studies, which extend previous work performed at the impact energy of 35 keV, give evidence for a dielectronic excitation process produced by electron-electron interaction. At impact energies in the range 5–170 keV, the cross sections are found to be larger than ${10}^{-17}{\mathrm{cm}}^2.$ Molecular-orbital energy diagrams were determined to analyze details of the collision. Analytic models were used to evaluate cross sections associated with dielectronic excitation. The results show good agreement with experiment. The dielectronic excitation process is dominant when three electrons from the target are transferred into an excited state of the projectile.

• Received 24 November 1998

DOI:https://doi.org/10.1103/PhysRevA.59.4399