Influence of Spur Processes on Positronium Formation in Some Mixtures of Organic Liquids

To test some predictions of the spur reaction model of positronium (Ps) formation, positron lifetime studies of the following binary organic mixtures: (a) dioxane/n-heptane, (b) triethylamine/n-heptane, (c) pyrrolidine/n-heptane, and (d) carbon disulphide/n-hexane were performed. The results were in agreement with the model, which explains the influence on Ps formation by proton spur reactions (cases a, b, and c), solvation of spur electrons and positron (cases b and c), and electron trapping on carbon disulphide combined with high electron mobility in pure carbon disulphide (case d). The ortho-Ps lifetimes were compared with the predictions of two theoretical models, none of which could reproduce the lifetimes in detail.