EVIDENCE FOR A SIGNIFICANT ABOVE-SURFACE CONTRIBUTION TO THE INTERACTION OF VERY SLOW H-LIKE IONS WITH SURFACES

We present secondary electron spectra of the H-like ions C5+ through N e9+ interacting with conducting surfaces at variable energies down to 8 eV per charge. The detailed identification of the K and L Auger spec tra and their evolution as a function of charge and energy of the ions reveals evidence for the neutralization and a significant de-excitati on of atoms with giant inversion of population in front of the surface . From C to Ne a decreasing fraction of spectral features is assigned to de-excitations during reflection of the projectile at the surface.