Interpreting the data on helium-ion scattering in metallic films
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Earlier measurements of angular distributions in the multiple scattering of a helium-ion beam with energy below 300 keV on Al yielded rather unexpected results: the ratio between the half-width of the measured angular distribution, (θ1/2)e, and that predicted with the Moliere–Bethe theory, (θ1/2)MB, proved to stay almost constant throughout the investigated energy range. At the same time, one could expect the (θ1/2)e/(θ1/2)MB value to be affected by the beam-content variation due to the charge–exchange scattering. Towards resolving this problem, we compute the interaction potentials between the Не++, Не+, and Не0 ions and the scattering atoms and reveal the electron-screening effects on the scattering process. Thereby, we explain the energy dependence of (θ1/2)e/(θ1/2)MB observed in the old and new measurements carried out at higher beam energies.
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- 1.A. A. Bednyakov, V. G. Ignatov, A. F. Tulinov, and Yu. N. Shustikov, “Multiple scattering and energy loss of helium ions in aluminum at energies below 300 keV,” Vestn. Mosk. Univ., Ser.: Fiz., Astron., No. 4, 402 (1971).Google Scholar
- 4.A. A. Bednyakov, Yu. V. Bulgakov, I. D. Koshevoi, V. S. Nikolaev, and V. P. Sobakin, “Angular scatterings of helium ions, scattered by thin metal films,” in Proceedings of the 8th All-Union Workshop on Physics of Interaction of Charged Particles with Single Crystals (Mosk. Gos. Univ., Moscow, 1977), p. 128.Google Scholar