Berlin 2001 – scientific programme

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A: Atomphysik

A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)

A 12.36: Poster

Thursday, April 5, 2001, 12:30–15:00, AT3

Application of Lennard–Jones (6,12) interaction potential for description of atomic collisions — •Zielinska-Kaniasty Sylwia — Institute of Mathematics and Physics, Technical and Agriculture University of Bydgoszcz, Al.Kaliskiego 7, 85-796 Bydgoszcz, Poland

Collisional kernels conveniently describe the velocity changing collisions. These kernels depend on interaction potential and there is a necessity for evaluating them from realistic interatomic potentials. In this paper we present the method of evaluating the kernels in the eikonal approximation. We discuss the influence of the potential parameters R and E on kernel’s width for a given atomic state. It turns out that, unlike collision kernel for the hard-sphere model, the Lennard–Jones kernel is not so sensitive to changes of R, as the previous one. The analysis shows, that for small velocities v the Lennard–Jones collision kernels decay slower then exp[−α v²]. It is interesting to note that the exponential approximation is justified only for the kernel’s wing. Contrary to the general tendency of approximating collisional kernels by the Gaussian curve, kernels for Lennard–Jones potential do not show such a behavior for all range of velocities.