Time dependent simulations of electron emission in grazing ion surface collisions

D.M. MITNIK, I. ALDAZABAL, A. ARNAU, M.S. GRAVIELLE, J.E. MIRAGLIA, AND V.H. PONCE

Schloss Hernstein, Austria

Conferencia; 16th International Workshop on Inelastic Ion--Surface Collisions (IISC-16); 2006

Spectra of electrons emitted in grazing ion-surface collisions provide information about the structure of the surface, and has been the subject of intense research in the past years. In particular, it is interesting to study the electron distribution around the direction of the specular reflection of the projectile, where the spectrum displays a sharp peak [Groeneveld et al. 1984], known as the "convoy" peak. However, the shape and position of the convoy peak are affected by surface potential produced by the ionization of the target (the "track potential"). In this work, we developed a numerical method for treating the surface track potential, expanding it in spherical coordinates around the colliding ion. We assume that the ion capture an electron from the surfaces, leaving it in a particular continuum state. The formation of a charge distribution in the surface behind the projectile, breaks up the spherical symmetry of the captured electron distribution, producing an electron emission spectra that is not necessarily centered around the ion.