Lifetimes of metastable states of noble gases

Abstract

The lifetimes of the lower metastable states of helium, neon, and argon have been studied as a function of the pressure and temperature of the parent gas and the size of the container. The lifetimes were determined from measurements of the decay constant of the radiation absorbed by the metastable atoms. At low metastable concentrations the loss is by diffusion to the walls of the absorption cell and by collisions with neutral atoms within the volume of the cell. The data indicate that at 300ÂK and sufficiently high pressures, the volume destruction of the lower neon metastable is directly proportional to the pressure as expected for two-body collisions. The volume destruction of the lower neon metastables at 77ÂK and the helium triplet metastables at 300A