Positron annihilation in alphahyphen;cyclodextrin: Effects of adsorbed gases

摘要

Positron annihilation lifetime measurements have been made for various adsorbed gases in the organic clathrate agr;hyphen;cyclodextrin. agr;hyphen;cyclodextrin samples were investigated under vacuum, saturated with water vapor, and under pressure of the following gases: O2, NO, N2O, CO2, He, He2, N2, and CH4. Water vapor produces a quenching of orthopositronium. Oxygen, nitric oxide, and nitrous oxide were each found to inhibit positronium formation. The interaction between Ps and these adsorbed molecules is different from that found in the gaseous state. Other gases studied had little or no effect upon the positron lifetime spectrum.