抄録
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.