Post-collision interaction in photoexcited argon LMM Auger processes

The L 23 M 23 M 23 Auger electron spectra of argon produced by photoionisation have been studied. The range of photon energy is from 249 eV, just above the L 3 edge, to 270 eV. The closer the photon energy is to the threshold, the more conspicuously observed is the effect of the post-collision interaction as a shift of the peak and an asymmetric profile in each Auger line. The observed dependence of the energy shift upon the kinetic energy of the photoelectron has been compared with the semiclassical theory, after Niehaus (1977), and the mean lifetime for the Auger decay of an inner-shell hole is deduced to be 2.4*10 -14 s.