Electron and positron backscattering in the medium-energy range.

Experimental data for positron and electron backscattering from thick solids are presented as a function of incident and outgoing angles and energies, and of target atomic number. A full description of the experimental features and limitations is presented. The data are compared with Monte Carlo calculated backscattering distributions, and in all cases the agreement is extremely good. Specularlike scattering for positrons incident at oblique angles is observed and explained in terms of the strength of the elasticscattering interaction