Relative transmission of 0.324- and 0.544-MeV positrons and electrons in Be, Al, Cu, Ag, and Pb

Abstract

The transmission of positrons from $^{65}\mathrm{Zn}({E}_{max}0.324 \mathrm{MeV})$ and $^{22}\mathrm{Na}({E}_{max}0.544 \mathrm{MeV})$ in Be, Al, Cu, Ag, and Pb were compared with that of electrons of identical energies. The comparison of their mass absorption coefficients ($\frac{\ensuremath{\mu}}{\ensuremath{\rho}}$) indicates a small but finite difference, implying greater transmission of positrons than electrons, with the exception of 0.324-MeV particles in Be and Al. These measurements were performed at atmospheric pressure. The results obtained clarify the existing ambiguity in the literature and are in agreement with multiple-scattering theory.