Der Beugungseffekt bei der elastischen Streuung von Ionenstrahlen an Atomen

For the elastic scattering of ion beams at atoms the diffraction of the matter wave at the atom can be observed in the region of small scattering angles and high energies. The diffraction causes undulations in the differential scattering cross section. In this paper a general solution of the diffraction effect is given. The solution holds for the Yukawa type screened Coulomb potential which is well suited for the small angle scattering of-ions at atoms and which contains two parameters. The computations have been made using the partial wave method and the Jeffreys-Born-approximation for the scattering phase shifts. The solution is presented in a form in which the amplitudes and characteristic constants of the first four undulation maxima and minima are given in dependence of a product which contains one of the potential parameters. The characteristic constants are correlated in a characteristic equation with the second potential parameter and the positions of the diffraction extrema. The conditions for the appearance of the diffraction effect are discussed.