RADICAL AND MOLECULAR YIELDS IN WATER IRRADIATED BY GAMMA RAYS AND HEAVY IONS

Nitrous oxide solutions containing separately ethanol, sodium deuterioformate, or potassium nitrite were irradiated with Co60 γ rays, 18-MeV deuterons, and 32- and 12-MeV helium ions in order to obtain the variation of the hydrated electron yield, the hydrogen atom yield, and the molecular hydrogen yield with the linear energy transfer (LET) of the radiation. It was found that the hydrogen atom yield does not increase with LET as the molecular hydrogen does nor does it decrease as rapidly as the electron yield. The results are compared with the diffusion model of spurs and tracks and are in agreement with the previous conclusion that hydrogen atoms are produced both by direct action on the water and by reaction of the hydrated electrons with hydrogen ion in the tracks. The much smaller perhydroxyl radical yield was also measured for these particles in copper sulfate-ferrous sulfate solutions.