M/sub 4,5/N/sub 4,5/X Auger electron spectra of iodine and xenon Many-body effects

High-resolution M/sub 4,5/N/sub 2,3/N/sub 4,5/, M/sub 4,5/N/sub 4,5/N/sub 4,5/, and M/sub 4,5/N/sub 4,5/O Auger spectra from I/sub 2/ vapor and from Xe gas have been measured using electron-beam excitation. In order to reduce satellite backgrounds, the M/sub 4,5/N/sub 4,5/N/sub 4,5/ spectra were also taken using primary-beam energies just below the core-ionization energy of the M/sub 3/ levels of iodine and xenon. The relative line energies and intensities for all of the xenon spectra and for iodine M/sub 4,5/N/sub 4,5/N/sub 4,5/ spectra have been calculated in the mixed-coupling scheme. The agreement between theory and experiment is excellent for the M/sub 4,5/N/sub 4,5/N/sub 4,5/ spectra of both xenon and iodine. The agreement for the xenon M/sub 4,5/N/sub 2,3/N/sub 4,5/ spectrum is less good, but is close enough to indicate the approximate validity of the independent-electron model. This result is in contrast to that for one-hole states involving the N/sub 2,3/ shell; such a model fails completely to account for the xenon 4p photoemission spectrum. The independent-electron model will not account for the M/sub 4,5/N/sub 2,3/N/sub 4,5/ spectrum of iodine. Reasons for the success of this model for xenon and its failure for iodine are presented. The observed inherent linewidths of the Augermore » lines are considerably broader in molecular iodine than in xenon. The photoelectron spectra and core-ionization energies of the 3d, 4s, 4p, 4d, 5s, and 5p levels of I/sub 2/ have been measured. The role of extra-atomic relaxation in the observed Auger energies is discussed.« less