Collection efficiency of electrons injected into dense argon gas by means of photoelectric effect

We report experimental results on the collection efficiency of electrons injected into dense Ar gas by means of photoelectric effect at the temperature T=142.6 K for several gas densities as a function of the applied electric field. The data can be interpreted in terms of the Young-Bradbury model if multiple scattering effects are taken into account when computing the electron-atom scattering cross section.