Doppler Broadening Measurement of Positron Annihilation in KCl and RbBr Crystals

Abstract

Doppler broadening method of positron annihilation radiation has been applied to the study of anisotropies of momentum distributions for KCl and RbBr crystals. Positron annihilation radiations were measured with a Ge(Li) detector. Anisotropies among the [100], [110] and [111] directions were measured in detail for the KCl and RbBr crystals. The result shows that the observed anisotropies are consistent with the theoretical estimates based on the Brillouin zone.