In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Professors P. Kleiber and K. Sando of the University of Iowa will continue their investigations of state-resolved molecular dynamics using `half-collision` methods. They pioneered the application of the technique known as scattering state spectroscopy in order to study inelastic (including chemically reactive) collisions. In this project they will extend these experiments to collisions of metal atoms with the molecules H2 and CH4. Another, new technique involves `fractional collisions,` in which scattering resonances in a metal-ion/molecule collision complex are detected using orbital-following models. These are somewhat complementary techniques which help describe different aspects of the collision process. %%% Theoretical models exist for the photodissociation of alkali diatomic molecules, but such theories are often not amenable to simple physical interpretation and can not easily be applied to complex dissociation processes. In some cases of current interest, such as collisions between ultra-cold atoms, the underlying physics is not understood well enough to allow application of theoretical methods with confidence. The results of these experiments on reactions between excited metal atoms and molecules in relatively simple systems will allow theoretical dynamical models to be tested before applying them to more complicated problems in the domain of collision and photodissociation dynamics. Practical applications include a better understanding of chemical vapor deposition processes
