G. Varga, E. Balázs* and L. Füstöss
Budapest University of Technology and Economics, Institute of Physics, Budafoki s. 8, Budapest, Hungary, H-1111
A numerical inverse procedure has been developed in the case of thermal energy atomic scattering from solid surfaces (TEAS). TEAS is characterised as one particle quantum mechanical system1,2 that led up to the solution of inverse scattering problem of 3D time dependent Schrödinger equation (ITDSE). The unknown parameters of the semiempirical interaction potential have been determined from the measured intensity distribution of He-Rh(311) system3 . A starting data set is provided by the inverse hard corrugated wall model. Further refinement has been received by ITDSE. The procedure is based on the trial-and-error-method. The norm of the difference of measured and computed intensity distribution is minimised by gradient method, constrained method and simplex method. This procedure resulted a fitted interaction potential. The solid surface has been considered as a frozen non-vibrating system. However, the new model was able to consider the shape of the diffraction peaks, because the He beam has been characterised not as an ideally monochromatic wave but a Gaussian wave-packet. This fact means a more realistic discussion of He-Pd(311) system.
1. G. Varga, Applied Surface Science, (1999) vol.144-145 p. 64-68.
2. G. Varga, Surface Science, (1999) vol. 441 p. 472-478.
3. R. Apel, D. Farías, H. Tröger, E. Kristen, K.H. Rieder,
Surface Science, (1996) vol. 364 p. 303-311.