Radiation Chemistry: Surface Science Techniques Chris Arumainayagam Department of Chemistry, Wellesley College, Wellesley, Massachusetts, U.S.A. Petra Swiderek Department of Applied and Physical Chemistry, University of Bremen, Bremen, Germany Katherine Tran Radiation Chemistry, Sherbrooke Central University, Fleurimont Hospital, Sherbrooke, Quebec, Canada

Abstract: Low-energy electron-induced reactions are thought to play a pivotal role in high-energy radiation-induced chemical reactions in condensed matter. This entry discusses the use of surface science techniques to analyze low-energy (£50 eV) electron-induced processes relevant to condensed-phase radiolysis. Surface science techniques are particularly suitable because such experiments are typically conducted using nanoscale thin films of multilayer adsorbates. Electron-stimulated desorption (ESD) experiments, conducted during irradiation, have yielded vital information relevant to initial electron-induced processes. In addition, analyzing the products following low-energy electron irradiation has provided new insights into radiation chemistry. The surface science techniques temperature-programmed desorption (TPD), reflection absorption infrared spectroscopy, X-ray photoelectron spectroscopy, and high-resolution electron energy loss spectroscopy are particularly useful for post-irradiation analysis. For example, postirradiation TPD has been shown to be capable of identifying labile radiolysis products, as demonstrated by the first identification of methoxymethanol as a methanol radiolysis product. Results of ESD and postirradiation surface science studies have been used not only to identify radiolysis products, but also to determine the dynamics of electron-induced condensed-phase reactions. In addition, such studies may also provide information valuable to 1) understanding the role of electron-induced single strand breaks in DNA leading to mutagenic damage; 2) explaining the electron-induced decomposition of feed gases used in the plasma processing of semiconductor devices; 3) illuminating the dynamics of electron-induced oligomerization and/or polymerization; 4) advancing cost-efficient destruction options for hazardous chemicals; and 5) explicating the astrochemistry of icy grains.