M4,5N4,5X AUGER-ELECTRON SPECTRA OF IODINE AND XENON - MANY-BODY EFFECTS

High-resolution M4,5N2,3N4,5, M4,5N4,5N4,5, and M4,5N4,5O Auger spectra from I2 vapor and from Xe gas have been measured using electron-beam excitation. In order to reduce satellite backgrounds, the M4,5N4,5N4,5 spectra were also taken using primary-beam energies just below the core-ionization energy of the M3 levels of iodine and xenon. The relative line energies and intensities for all of the xenon spectra and for iodine M4,5N4,5N4,5 spectra have been calculated in the mixed-coupling scheme. The agreement between theory and experiment is excellent for the M4,5N4,5N4,5 spectra of both xenon and iodine. The agreement for the xenon M4,5N2,3N4,5 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 N2,3 shell; such a model fails completely to account for the xenon 4p photoemission spectrum. The independent-electron model will not account for the M4,5N2,3N4,5 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 Auger 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 I2 have been measured. The role of extra-atomic relaxation in the observed Auger energies is discussed. © 1979 The American Physical Society.