Photoelectron collection efficiency in Xe-CF4 mixtures

A Monte Carlo simulation is used to study electron drift parameters in CF₄ and Xe-CF₄ mixtures as well as the collection efficiency f for photoelectrons emitted from a Csl photocathode into these gases. The present calculations take into account superelastic collisions of the electrons with CF₄ molecules thermally excited to vibrational modes, and results are compared with earlier results where the effect was neglected. The data for f is also compared with previous results in CH₄ and Xe-CH₄. The simulation examines the dependence of f on the reduced electric field E/N, incident photon energy E_ph and mixture composition.