Reactions of radiation induced OH radicals in water

Hirade, Tetsuya

no journal, , 

Irradiation causes ionization and excitation in water and the cation formed by the ionization reacts with a water molecule to form OH radical immediately. OH radical is one of very reactive species and plays an important role in DNA damage and corrosion of materials, etc. The triplet Positronium (ortho-positronium; o-Ps) lifetimes obtained by positron annihilation lifetime (PAL) measurements in water are shorter at higher temperatures, while the lifetimes in many other liquids are longer. It is because reactions between irradiation induced reactive species and o-Ps shorten the lifetime. I have been indicating that positron annihilation age-momentum correlation (AMOC) measurements can be applied to investigate the reaction of o-Ps and OH radicals. Although the PAL results indicate that the reactions between o-Ps and reactive species become smaller at lower temperatures, o-Ps and OH radical pairs having electron spin correlation can react even at lower temperatures than 10C. Apparently inconsistent results obtained by PAL and AMOC can say that water structure play an important role on reactions of OH radicals.