Enhancement of the Long-Lived Positronium Annihilation Rate by a Static Electric Field

Abstract

The annihilation rate of the long-lived component of positronium in solid dielectrics was investigated as a function of an applied static electric field. It was found that in some materials like paraffin, polyethylene, and Teflon the triplet positronium decays, in the presence of the field, at a rate greater than the usual "pickoff" annihilation rate. Within the experimental accuracy the lifetimes $\tau$ in the three materials display the same trend with the field, which is expressed by the equation ${\tau }_E={\tau }_0(1-\alpha E)$, where $\alpha =(9.3\mathrm{}\pm 1.3)\times {10}^{-4\mathrm{}}$ cm/kv. No effect was found in some typical polar polymers, for instance, Lucite, Nylon, and polyvinyl chloride.