Our research is focused on understanding the dynamics of reactions at the gas/surface interface, especially under conditions where the reactants are highly energetic.

• Ion/surface collisions initiate electron transfer, dissociative scattering, and atom abstraction reactions. Experiments directly measure the effects that initial translational and vibrational energies, internuclear-axis direction, and impact site exert on the reactivity of a molecular ion at a metal, semiconductor, oxide, or polymer surface. Through experiments and model simulations, the detailed atomic motion associated with hyperthermal molecule/surface reactions is elucidated.
• The degradation of spacecraft materials in the low-earth orbit (LEO) environment arises from energetic bombardment by hyperthermal atomic oxygen, ions, electrons and photons. We have launched experiments on the International Space Station and are conducting ground-based experiments to identify the role of oxygen ions in the erosion of polymeric materials in LEO.
• As an alternative approach to initiating surface chemical reactions under nonthermal conditions, nanoscale devices are fabricated to deliver ballistic substrate electrons to the vacuum/solid interface. The optimal design and application of these metal-insulator-metal devices is under investigation.