Drs. Gentry and Giese plan to continue and expand a program of research involving the following types of experiments. (1) Molecular beam experiments will be carried out to measure differential cross sections for the benchmark chemical exchange reaction between deuterium atoms and hydrogen molecules. (2) Photodissociation dynamics for both small and large molecules will be examined by time-of-flight measurements on the fragments with very high resolution. (3) The decay of weakly-bound molecular clusters will be measured in real time following vibrational excitation of the cluster, in order to study the dynamics of energy flow within the cluster. (4) A new apparatus incorporating vacuum-UV photoionization and mass spectral analysis will be used to measure cross sections for growth, exchange, and metathesis reactions of weakly bound clusters as functions of kinetic energy. (5) Energy flow and reaction dynamics in electronically excited states of simple van der Waals molecules will be examined by laser induced fluorescence and chemiluminescence spectroscopy. (6) A unique time-of-flight apparatus will be used to study the properties and applications of extreme gas expansions in generating super-cold gas phase species. These investigators have made and are continuing to make important new technical constributions to experimental capabilities. The pulsed nozzle which they developed has been adopted by many other groups. Their proposed work on generating super-cold gas phase species is also expected to find applications in future research. The importance of the hydrogen exchange reaction is its extreme importance for fundamental and rigorous comparison between theory and experiment in chemical kinetics. Experiments with super-cold molecules are expected to provide data which will be sufficient to distinguish between competing theories.
