Positron Annihilation in Diatomic Crystals

摘要: The angular correlation between the two photons created by annihilating positron-electron pairs in lattices with a basis is derived various approximations. effects of temperature as introduced through momentum distribution positrons and lattice vibrations are examined. Self-consistent electron wave functions exchange calculated for LiH crystal cell approximation. resulting x-ray structure factors close agreement recent extensive experimental data Calder et al. positron function obtained same approximation calculated. apparent discrepancy noted Stewart March their angular-correlation density consistent can be traced to phase relations within unit basis.