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Roy L Champion Experimental Atomic, Molecular and Optical Physics BS North Carolina State University 1960 PhD University of Florida 1966 My work is focussed upon the two somewhat distinct areas of ion-atom and ion-surface collisions. Experiments in the field of ion-atom collisions are designed to measure various total and differential cross sections, and to develop a general understanding of the dynamics of those collisions. Systems which we have investigated range from one of the most elementary (H- + H) to the very complex (SF6- + SF6). Results of these experiments provide information essential to an understanding of macroscopic phenomena such as the composition of stellar atmospheres (H- + H) and the behavior of SF6 as an insulating gas in high voltage environments. Collisions of ions and atoms with metallic surfaces leads to the ejection of secondary electrons, ions and atoms. That ejection process is poorly understood, especially as a metallic surface acquires an oxygen coverage. The surface experiments are devised to measure absolute ejection efficiencies for various surface conditions. Again, these fundamental processes are important in a wide variety of applied areas, ranging from particle detectors to the modeling of gaseous discharges which are bounded by metallic electrodes. Research group web page.
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Resent Publications: "Secondary electron and negative ion emission from Al: Effect of oxygen coverage," Phys. Rev. B 53, 14127 (1996). "Total Cross Sections for low energy collisions of H3+ with molecular hydrogen and rare gases", J. Chem. Phys. 107,1156 (1997). "On the dynamics of secondary-electron and an ion emission from an Al/O surface", Surf Sci. 382, 137 (1997). "Ion-induced secondary electron and negative ion emission from Mo/O", Surf. Sci. 410, 258 (1998). "Negative ion emission from a stainless steel surface due to positive ion collisions", J. Appl. Phys. 84, 1706 (1998). |