This award supports Professors Norman Tolk and Royal Albridge, Jr., of Vanderbilt University to continue their productive collaboration in experimental surface physics with Professors Wolfgang Husinsky and Gerhard Betz of the Institute of General Physics of the Technical University of Vienna, Austria. They are carrying out cooperative investigations of the microscopic electronic mechanisms responsible for the final states of particles which are emitted from surfaces due to bombardment of photons, electrons and ions. Their goal is to gain basic understanding of the way in which energy from directed beams may be absorbed, electronically localized and ultimately transformed at various surfaces into internal and kinetic energies of the emitted particle. The Viennese group is a world leader in the detection and characteri- zation of sputtered particles produced by ion-surface collisions using optical techniques, in particular, laser-induced fluorescence. The Vanderbilt group has been studying the strictly electronic desorption processes associated with electron and UV photon bombardment of solid surfaces. Through collaboration, they have demonstrated that it is possible using laser-induced fluorescence techniques to identify specific excitonic and defect channels through which incident beam energy flows as it breaks bonds in the surface and near-surface bulk in pure crystalline materials. They have also begun studies of the effect of thin adsorbed layers on desorption induced by electronic transitions.
