Measurement of Differential Cross Sections for the Elastic Scattering of Positrons by Argon Atoms

Abstract

Direct measurements of differential scattering cross sections for positron-gas-atom collisions are reported. The apparatus used exploits the time-of-flight technique. Results for positrons of mean energy 2.2, 3.4, 6.7, and 8.7 eV elastically scattered through angles between 20\ifmmode^\circ\else\textdegree\fi{} and 60\ifmmode^\circ\else\textdegree\fi{} by argon atoms are presented. Sources of experimental error are discussed and comparison with recent theoretical calculations is made.