Radiation chemistry and photochemistry

Progress is reported in two of the areas made accessible by picosecond pulse radiolysis. The chemical history of the hydrated electron in the spur has been determined, and reactions of the hydrated electron with high concetration of solute have been measured and explained. Other studies reported on are initial work of heavy-ion pulse radiolysis and nonequilibrium spin populations in radicals. In the area of pulse radiolysis of gases progress is reported in studies on reactions of the hydroxyl radical, production of the OH radical in hydrocarbon--oxygen systems, reaction of chlorine atoms and and chlorinated radicals, reaction of CN with H2, and mechanisms of excited state formation. (U.S.)