Exciton lifetimes in electron beam excited condensed phases of argon and xenon

Abstract

We report measurements of lifetimes of trapped excitons in condensed argon and xenon. For argon, decays are qualitatively similar to those found in the gas phases. For xenon, we find by both spectroscopy and the time dependence of the fluorescence that the n=1 and n=2 Γ (3/2) excitons radiating at 175 and 164 nm, respectively, are present for all temperatures from 80–133 K. The measured decay times are found to be independent of temperature and density. We discuss the validity of decay time measurements when using electron beams for excitation.