Effect of added water on the radiolytic hydrogen yield and the positronium formation probability in liquid dioxane

Ortho-positronium (o-Ps) intensity measurements were made in dioxane-water mixtures (DWM) over wide concentrations ranges, the purpose was to compare the changes in radiolytic hydrogen yields and o-Ps formation probability when dioxane is replaced by water. Water leads to a partial inhibiting of Ps formation and enhances the H2 yield. The result points to the possibility of understanding H2 and Ps formation in DWM on the basis of the previously formulated unified model for positronium and radiolytic hydrogen formation, if structure peculiarities of DWM are taken into account. The arguments are given that the influence of added on the hydrogen formation in the radiolysis of DWM is not associated with the proton transfer from radical cations of dioxane to water molecules but due to the capture of quasi-free electrons escaped the intra track recombination with ions by water clusters took place in dioxane solutions of water. (authors)