Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 12: Posters Thursday (Ion/Atom/Molecule/Surface Scattering)
A 12.30: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT3
Electron emission from polycrystalline Al and Cu surfaces measured in coincidence with reflected projectiles in collision with 8 keV H+ and H — •Shah Mansukh1, Z Szilagyi1, T C McGrath1, R W McCullough1, H Jouin2, and J M Woolsey3 — 1Department of Pure and Applied Physics, Queen’s University, Belfast BT7 1NN, UK — 2Universite de Bordeaux I, Centre Lasers Intenses et Applications, France — 3University of Stirling, Department of Biological Sciences (Physics), Stirling FK9 4LA, UK
Electron emission in ion impact on metallic surfaces arises through Kinetic Emission (KE) and Potential Emission processes. For 8 keV H+ and H neutral projectiles KE processes dominant. We have carried out the measurements of secondary emission coefficient from clean surfaces of Al and Cu at an incidence angle of 10 degrees with respect to the surface. Secondary electrons are detected by a Si barrier electron statistics detector and counted in coincidence with the reflected projectiles separated into their various charge states. The coincidence technique enables selective recording of electrons that are emitted close to or near the surface. This will provide information on collisions that take place near the surface/vacuum interface. A comparison of KE obtained from Al and Cu surfaces will be presented and these will be interpreted in terms of differences in their work functions and their densities of states at the surface. Attempt will also be made to investigate the role played by Potential Emission (PE) processes in these systems.