MULTIPLE PHOTO-IONIZATION OF XENON

The photoionization cross sections for the production of Xe+, Xe++, and Xe+++ have been measured in the energy range 28-83 eV. At energies between the thresholds for Xe++ production 33.3 eV and 4d-electron removal 67.55 eV, the Xe++ cross section reaches about one-third of the total cross section. This cannot be accounted for by an independent electron model in terms of an electron shake-off process. At energies greater than 67.55 eV, both the Xe+ and Xe++ cross sections increase; here the singly charged ion should be accompanied by fluorescence and the doubly charged ion can result from a simple Auger process. The triple ionization is attributed to a process which involves first the removal of a 4d electron and then an Auger event in which two electrons are emitted simultaneously. © 1969 The American Physical Society.