Fundamental studies of energetic ion beam/solid surface interactions

An experimental investigation into the means by which intact neutral species are desorbed from a keV ion-bombarded surface has been conducted. Quantum state specific mass, energy, and angle distributions of the desorbed species are acquired to determine the desorption mechanisms. Surface chemistry and physical factors are probed to determine their influence on the emission mechanism. Self-assembled mononlayers of thiol-containing organic molecules chemisorbed to gold surfaces are utilized to study desorption from chemisorbed systems. Most of the organic molecules from a chemisorbed monolayer are desorbed by a thermal mechanism. Benzene and phenol molecules physisorbed to a silver surface are studied to probe desorption from physisorbed systems. A ballistic mechanism is responsible for the emission of molecules from a monolayer of physisorbed molecules. Silver atoms and benzene molecules are utilized to study how analyte species' location in the sample matrix affects the emission characteristics, especially the characteristics of internally excited species. Species detected in an internally excited state must originate from very near the surface/vacuum interface.