Post-collision interaction and the Auger lineshape

The effect of a slowly receding electron on the shape and location of an Auger line is investigated for Auger transitions following photoionisation of an inner-shell electron. The theory of Niehaus and Morgenstern (1977) is reformulated and extended to take into account the time it takes for the fast Auger electron to overtake the slow electron. Because of this, much smaller shifts are found in the energies of the peaks of the Auger spectrum than those predicted by Niehaus (1977) as a result of post-collision interaction. In addition it is demonstrated that the truncation of the leading edge of the Auger lineshape associated with Niehaus' work is not a failure of the theoretical model, but is solely an artefact arising from the use of the stationary-phase approximation to evaluate the integral which follows from the model. The extended theory is generalised to treat inner-shell vacancies caused by electron impact ionisation near threshold, in which case the effect on the Auger line is caused by the two slowly receding electrons.

[1]  J. Mizuno,et al.  Classical and quantal Auger profiles due to inner-shell photoionisation near threshold , 1984 .

[2]  G. Ogurtsov.  Auger line shift due to the post-collision interaction at large excess energies , 1983 .

[3]  D. A. Shirley,et al.  Electron-spectroscopy study of inner-shell photoexcitation and ionization of Xe , 1983 .

[4]  K. Siegbahn,et al.  An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra Revealing New PCI Effects , 1983 .

[5]  A. Niehaus,et al.  Angular momentum exchange in post collision interaction , 1983 .

[6]  K. Siegbahn,et al.  Line sharpening effect due to PCI in Ar LMM Auger spectra: experimental and theoretical results , 1982 .

[7]  F. Wuilleumier,et al.  Post-collision interaction in inner-shell ionization: The xenon case , 1981 .

[8]  A. Niehaus.  Analysis of post-collision interactions in Auger processes following near-threshold inner-shell photoionization , 1977 .

[9]  A. Niehaus,et al.  Interference of autoionizing transitions in time-dependent fields , 1977 .

[10]  F. H. Read.  The analysis of post-collision interactions in ejected-electron spectra , 1977 .

[11]  F. H. Read,et al.  Structure near autoionizing energies in the excitation of bound states of helium, neon and argon by electron impact , 1975 .

[12]  H. W. Berry,et al.  Electron Energy Distributions from Ionizing Collisions of Helium and Neon Ions with Helium , 1966 .

[13]  G. Wannier.  The Threshold Law for Single Ionization of Atoms or Ions by Electrons , 1953 .