Calculation of the Doppler broadening of the electron-positron annihilation radiation in defect-free bulk materials

Results of a calculation of the Doppler broadening of the positron-electron annihilation radiation and positron Lifetimes in a large number of element al defect-free materials an presented. A simple scheme based on the method of superimposed atoms is used for these calculations. Calculated values of the Doppler broadening are compared with experimental data for a number of elemental materials, and qualitative agreement is obtained. These results p rovide a database which can be used for characterizing materials and identi fying impurity-vacancy complexes.