Radiolysis
Radiolysis is the dissociation of molecules by ionizing radiation. It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux. The radiation in this context is associated with ionizing radiation; radiolysis is therefore distinguished from, for example, photolysis of the Cl2 molecule into two Cl-radicals, where (ultraviolet or visible) light is used.
For example, water dissociates under alpha radiation into a hydrogen radical and a hydroxyl radical, unlike ionization of water which produces a hydrogen ion and a hydroxide ion. The chemistry of concentrated solutions under ionizing radiation is extremely complex. Radiolysis can locally modify redox conditions, and therefore the speciation and the solubility of the compounds.
Of all the radiation-chemical reactions that have been studied, the most important is the decomposition of water. When exposed to radiation, water undergoes a breakdown sequence into hydrogen peroxide, hydrogen radicals, and assorted oxygen compounds, such as ozone, which when converted back into oxygen releases great amounts of energy. Some of these are explosive. This decomposition is produced mainly by the alpha particles, which can be entirely absorbed by very thin layers of water.
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