Surface state effects in electrón emisión from Beryllium surfaces

C. D. ARCHUBI; M. S. GRAVIELLE; V. M. SILKIN

Gatlinburg

Workshop; 18 th International Workshop on Inelastic Ion-Surface Collisions; 2010

       Recently it has been demonstrated that occupied surface states can modify the dielectric properties of metal surfaces [1]. Thus, with the aim of investigating the influence of surface states on electron emission, we study electron distributions originated by fast protons colliding grazing with a Be(0001) surface. Beryllium presents a technological interest in modern fusion reactors and it is expected that its surface states play an important role in inelastic electronic processes.       To describe the electron emission process we employ the Band-structure-based (BSB) model [2], which includes an accurate description of the electron-surface potential, incorporating information about the band structure of the solid.  Within the BSB approach the surface interaction is described by a realistic one-dimensional model potential [3], while the dynamic response of the medium is derived in consistent way from the unperturbed electronic states by using a linear response theory. This method has been succesfully employed to study energy loss and electron emission from Al surfaces, where the effects of the surface states were found negligible [4].