In this GOALI program the PI's are pursuing systematic studies of the key physical processes underlying the efficient hyperpolarization of He-3 and Xe-129 by spin- exchange optical pumping. Measurements focus on the determination of spin-exchange and spin-relaxation cross sections, optical pumping at high buffer gas pressures, the role of van der Waals molecules in high-pressure Xe cells, light transport in optically thick vapors, and relaxation processes which depolarize the species. This research is conducted by collaborators from the University of Wisconsin and Magnetic Imaging Technologies Incorporated (MITI), a newly-established company specializing in the commercialization of hyper-polarized noble-gas sources for use in medical diagnostics. The experiments are conducted by students working partly at the university and partly at the company laboratories. Partial funding is provided by the Office of Multidisciplinary Activities (OMA).