[en] In this work, it is discussed the main differences between the use of pseudo-potentials and model potentials in collision problems . It is shown the potential energy curves for distinct systems obtained with both kinds of potentials. (A.C.A.S.)

[en] A survey of the progress of the study of fast ion-atom collisions from 1933 til now is presented. 46 refs

[en] A brief critical review of some commonly used theories of ion-atom collisions is presented. (orig.)

[en] The hidden crossing theory employs an asymptotic wavefunction for three charged particles which derives from a solution of an open-quotes adiabaticclose quotes Hamiltonian with one reaction coordinate R, that measures that overall size of the system, held fixed. This theory has identified two mechanisms for ionization. It has recently been demonstrated that one mechanism is well represented by the asymptotic theory and gives the Wannier threshold law for ionization of atoms by charged particles. A second mechanism involving resonant states is less-well described, in that electron angular distributions are incorrectly represented. An expansion in complex Sturmian functions provides a nearly exact representation at low energy. Approximate evaluation of the expansion by the method of stationary phase recovers the original hidden crossing theory. When the expansion is evaluated directly, the electron energy and angular distributions are in agreement with experiment. The Sturmian basis for the theory will be described

[en] The workshop contains discussions about experimental and theoretical results in inner-shell ionization of atoms by light ion impact. (BRB)

[en] The topic of this review is the theory of collisions between ions and atoms at relative velocities which exceed the Bohr velocity of the target electron, or electrons, concerned in the excitation, ionisation or charge transfer process. Theoretical models for fast ion-atom collision can be roughly divided into expansion methods and perturbation methods and each of these are considered. 44 refs.; 6 figs.; 4 tabs

[en] The high energy double ionization of helium by light ions has been measured to have an interesting behavior as a function of projectile charge, Z_p. Firstly, cross sections are proportional to Z_p², not Z_p⁴, as would be expected in the independent particle model. And as the energy is lowered there are marked differences between cross sections produced by protons and anti-protons. It is believed that correlations in the helium system are responsible for the results though simple sudden approximation forms of shake-off effects give answers an order of magnitude higher than measured. The forced impulse method, a two electron, fully correlated pseudo-state expansion calculation reproduces most of the experimental features but is low in absolute magnitude by about 35%. This is ascribed to the truncation in angular momentum space used in the calculation where so far only single particle s- and p-states have been included in the basis. 22 refs.; 1 figure

[en] Abstract only

[en] A variational impact parameter approach to the excitation of atoms of ions at intermediate velocities, based on the Schwinger principle, has been very successfully used by previous authors to predict the saturation of cross sections when the projectile charge is increased. A new approach to the calculation of G+T, the target propagator, used in this treatment is reported. (author)

[en] The deviations of the experimental L-subshell ionization cross sections relative to the first order perturbation theories are discussed in terms of vacancy transfer between the L-subshells during the collisions, by means of a two-step model in the impact parameter formulation. (authors)