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The variation of the intensity of the Ne K - Auger line due to post-collision interaction has been measured as a function of the projectile energy at observation angle in 0.8 - 3.2 MeV - Ne collisions. The measured Auger-electron yield normalized to the theoretical or experimental total K-shell ionization cross section shows a strong enhancement when the projectile velocity is smaller than the Auger-electron velocity. The general agreement between the present experimental data and continuum distorted wave calculations provides a clear evidence that the observed impact-energy dependence is mostly due to the post-collision Coulomb focusing exerted by the projectile on the Auger electron.

Correlation effects on the relative intensities and anisotropy coefficients of angular distribution and spin polarization of the Hg N6,7O4,5O4,5 Auger transitions have been investigated, applying the relativistic Dirac-Fock model with intermediate coupling. The results are discussed and compared with former calculations and experiments. In particular, the influence of e-e correlations has been taken into account, including initial and final state configuration interaction. A small influence of correlations in general has been found except for the energetically near-threshold Auger lines. A drastic effect has been found for the angular distribution parameter of the N7O4,5O4,51D2 Auger line.

A joint experimental and theoretical investigation of the PL2, 3 VV spectrum from the InP(110) surface is presented. The aim is to check for the possibility of separately measuring its surface and bulk components. It is shown that non-reactive overlayers, such as Sb in this case, can be successfully exploited to this end. The comparison with computed spectra allows us to finally present the measured surface component of the PL2, 3 VV spectrum from InP(110).

Auger Line Shape Analysis from solids with open bands has been made considerable progress in recent years. Calculations on Graphite and Pd were encouraging, and new developements in the formalism look promising. However, it must be recognized that the current theory remains much more phenomenological and less predictive and reliable than it is for closed bands. In some sense, the comparison with experiments is more succcesful than our real understanding deserves. This is hardly surprising, in view of the much more fundamental character of the problems involved. An attempt will be made to assess the present state of the theory and foreshadow the directions of future research.

We present evidence for two-center interference effects in the autoionization of a Helium atom following a double capture process in a He2+ + H2 collision, by looking, not at the total intensity as in a previous article [1], but at the full width at half maximum of the energy distribution at a function of the observation angle.

The formation of titanium-silicon interfaces under different growth and annealing conditions is studied by a combination of techniques. The main emphasis is placed on a detailed comparison between experimental and theoretical determinations of the Si L23VV Auger line shape for different compositions of silicides. It is shown that this greatly enhances the potential of Auger electron spectroscopy for the determination of thin layers composition.

The authors present the first absolute experimental measurement of a finite PCI line shift of Auger electrons at high electron impact energies. The result confirms recent theoretical predictions about the shape of Auger lines after particle impact ionisation. In particular, it proves that Auger lines are never Lorentzians when obtained from non-coincident collisional ionisation experiments.

The authors have measured the energy shifts in of the Ne KL23L23 (1D2) Auger line (ionisation energy EB(Ne K)=870.3 eV, level width Gamma (Ne K)=0.27 eV) and of the Kr L3M45M45 (1G4) Auger line (EB(Kr L3)=1678.4 eV, Gamma (Kr L3)=1.17 eV) in a wide range of excess energies E1 up to an electron impact energy Eo=10 keV. The small experimental error of the authors data reveals a functional behaviour of the post-collision interaction (PCI) shift in (E1) different from in =c Gamma E-n1. The PCI shift does not follow a monotonic decreasing function in (E1) for all excess energies E1 but remains constant above a certain excess energy /E1, with /E1(Ne K) approximately=1 keV and /E1(Kr L3) approximately=3.5 keV. The authors give arguments for a non-vanishing PCI at large excess energies in the electron impact ionisation and give values for the absolute PCI shift in approximately for at energies E1 larger than /E1: in approximately Ne K)=48+or-12 meV, in (Kr L3)=102+or-25 meV and in approximately (Ar L3)=22+or-6 meV for Ar L3, which was studied previously by Graf and Hink (1985).

Different methods are used to obtain both the Auger widths and the relative Auger line intensities of some 2s2p6nln'l' Na terms. If the relative line intensities are expected to be correctly estimated in the distorted-wave method, the widths are overestimated owing to the use of the same 3s and 3p orbitals in the initial and final states.

The authors report measured post-collision interaction phenomena following K-shell ionisation of neon by electron impact. At near-threshold impact energy Ei electron spectra taken in the region of the K-L2,3L2,3(1D2) Auger line reveal a high-energy tail and an energy shift Delta E of this line, the latter obeying the Barker-Berry power law Delta E approximately (Ei-EK)-0.5 where EK is the K-ionisation energy. The intensity ratio of diagram Auger-lines changes noticeably with near-threshold impact energy.