Electron-impact ionization of the Kr atom

Electron-impact ionization cross sections are calculated for the ground configuration of the Kr atom. Time-dependent close-coupling cross sections for the direct ionization of the 4s and 4p subshells leading to single ionization are found to be a factor of 2 smaller than distorted-wave calculations due to the presence of strong continuum correlation effects. With the inclusion of relatively small $4s\to nl$ excitation-autoionization contributions, the total single ionization cross sections for Kr are found to be slightly larger than crossed-beams experimental measurements. (paper)