Impact parameter dependence of the electronic stopping in proton-solid-state atomic collisions

doi:10.1016/0168-583X(86)90241-7

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Volume 15, Issues 1–6, 1 April 1986, Pages 8-10

https://doi.org/10.1016/0168-583X(86)90241-7 Get rights and content

Abstract

In the local density approximation (LDA) the stopping power caused by the target electrons is calculated considering the response of an electron gas. Beyond the random phase approximation (RPA) the interaction of the electrons (exchange and correlation effect) is described by the dynamic local field correction. The free atom electron density is modified according to the Gertner model. Considering the interaction between the screened target nucleus and the proton as a classical two body scattering problem, the impact parameter dependence of the “friction force” is determined. The effective stopping power is calculated performing averaging over the volume of the target atom and over impact parameter.

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Recent experiments on electron emission from metals induced by impact of slow ions reveal long tails of the electron distribution at high energies. The impact energies are below the deep level excitation threshold and thus mostly valence electrons seem to contribute to the emission. In an attempt to explain this experimental observation the energy spectra of electronic excitations have been calculated in the local representation of valence electrons. The effect of deep inner shells has been accounted for by orthogonalizing the valence wave functions to the core wave functions. The admixture leads to excitations of electrons far above the classical limit of 2mvv_F where v is the velocity of the moving particle, m is the electron mass and VF is the electron velocity at the Fermi level.
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Abstract

References (18)

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Nucl. Instr. and Meth.

Nucl. Instr. and Meth.

Phys. Lett.

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J. exp. theor. phys.(USSR)

Cited by (9)

Incomplete melting of Pb(001) and vicinal surfaces

Kinetic electron emission from solids induced by slow particles

The energy loss of medium-energy He<sup>+</sup> ions backscattered from a Cu(100) surface

H<sup>+</sup> and He<sup>+</sup> stopping in a degenerate electron gas

Nonlinear calculations of the stopping power for slow hydrogen and helium projectiles in solids

Electronic energy loss of helium ions in aluminum