Total cross sections for the scattering of 2-50 eV positrons by helium and neon atoms have been measured using the time-of-flight technique, and are compared with recent experimental and theoretical results. The measurement of positron energies and the flight path length is described and possible sources of systematic errors, including the effects of small-angle forward scattering, are fully discussed.

• Received 31 July 1978

DOI:https://doi.org/10.1103/PhysRevA.20.145