Electron Emission for Grazing Slow Atom and Ion Impact on Monocrystalline Metal and Insulator Surfaces

Abstract

In grazing collisions of atoms and ions with monocrystalline surfaces, projectiles are scattered along defined trajectories, and electron emission therefore proceeds under well characterised conditions compared to large-angle impact on polycrystalline target surfaces. Total electron yields can be measured in coincidence with energy loss of scattered projectiles, down to 10 −4 electrons per projectile near the threshold for kinetic electron emission.In the present comment we demonstrate the recent experimental progress for grazing scattering of slow (>100 eV up to some keV per amu) atoms and multiply charged ions on metal (Au, Al) and insulator (LiF) surfaces. Observed kinetic and potential electron emission processes can be quantitatively explained in terms of simple model assumptions. These experiments are carried out in a practically non-destructive manner with intriguing aspects for novel surfaceanalytical applications. Physica Scripta 72 C Physica Scripta 2005 C Physica Scripta 2005 Physica Scripta 72

Fermi momentum above metal surface from electrons ejected by impact of He atoms

“…As an example, we mention studies on KE performed for impact under a grazing angle of incidence [3] where projectiles are reflected in front of the topmost surface layer with welldefined projectile trajectories. Different microscopic interaction mechanisms for KE from metal and insulator surfaces could be identified and analyzed in detail [3][4][5][6][7][8].…”

Polyatomic Ion-Induced Electron Emission (IIEE) in Electrospray Thrusters

“…Isolation of KE from secondary processes is therefore imperative. Recent work has demonstrated the ability to separate KE and PE contributions to electron emission utilizing grazing incidence projectiles on well prepared surfaces [70]. A more advanced computational theory including secondary processes is also necessary for comparison.…”