Binary mechanism in grazing ion-surface collisions

For ions grazingly impinging on solid surfaces, the mechanism of binary collision with the free-electron gas is investigated by employing a semiclassical formalism. The model is applied to the calculation of the energy lost by fast protons colliding with aluminum surfaces. Different transitions that contribute to the energy loss are analyzed. The total energy loss by binary collisions is compared with recent experimental data and results from the dielectric formalism. The energy spectrum of the ejected electrons is also studied, finding good agreement with the available experimental data for emission angles separated from the direction of specular reflection of the projectile. [S1050-2947(98)05312-8].