Gabor VARGA (associate professor)

Budapest University of Technology and Economics, Department of Physics, Budafoki u. 8, Budapest, Hungary, H-111

Soft corrugated potential model
Thermal energy atomic scattering (TEAS) is discussed within the soft corrugated interaction potential by perturbation theory. Inverse scattering problem is also discussed [1].

Hard corrugated wall model
A solution method of hard corrugated wall model (HCW) - so called  GR method - is improved . The stability and convergence is developed [3]. Inverse scattering problem is discussed by improved GR method [2][4]. The surface structure symmetry is considered at the computation. The computation time decreased to 2% in the best cases [5]. A special inverse scattering method has been developed. The intensity distribution and the Debye-Waller factor are fitted to the experimental result of He-LiF scattering in the same time. The Debye-Waller factors depend on the open channel, the scattering direction [6]

Wave packet model
Thermal energy atomic scattering is investigated by wave packet model. The independent atomic ensemble is described by an approriate Gaussian wave packet. The time dependent Schroedinger equation is solved by split operator  method numerically. Transfer width and resolution [7], periodical and stepped surface [8], computer simulation and animation [9] and the comparison of classical and quantum He scattering [10] are discussed in the case of TEAS.

1., Distorted wave Born-approximation for atom-metal surface scattering, E. Balázs and G. Varga, Vacuum 37 153-156, 1987.
2., Surface Reconstruction by simple Hard Corrugated Wall model computations G. Varga and L. Füstöss, Vacuum 41 315-317, 1990.
3., Simple Hard Corrugated Wall model computations L. Füstöss and G. Varga, Vacuum 40 47-50 1990.
4., Surface structure determination with Hard Corrugated Wall model, G. Varga and L. Füstöss, 1990. XI. Yugoslav Vacuum Congress, Zveza drustev za vakuumsko tehniko Jugoslavije, volume 24, p. 382-390 (1990).
5., Atomic Scattering computations by the hard corrugated wall model for symmetric experimental arrangements, G. Varga and L. Füstöss, Surface Science 243 23-30 1991.
6., Determination of Debye-Waller factors from elastic diffraction peaks of thermal energy atomic scattering from solid surfaces, Gábor Varga, Vacuum 50 339, 1998.
7., Resolution and transfer width of thermal energy atomic scattering from solid surfaces, G. Varga, Applied Surface Science, vol. 144-145 (1999) p.64-68.

8., Investigation of thermal energy atomic scattering from solid surfaces using 3D time-dependent Schrödinger equation, G. Varga, Surface Science, vol. 441 (1999) 472-478.
9., Computer simulated thermal energy atomic scattering on solid surfaces, G. Varga, Surface Science, vol. 482-485 (2001) p. 1152-1158.
10., Comparison of 3D classical and quantum mechanical He scattering on Rh(311), E. Balázs, G. Varga and L. Füstöss, Surface Science, vol. 482-485 (2001) p. 1145-1151.