Positron Annihilation in Deformed Copper

Abstract

Positron lifetime spectra were measured for Cu specimens with different concentrations of lattice defects. After subtracting the source components, lifetime spectra were successfully resolved into two components. Obtained results were quite consistent with those expected from the trapping model. The positron trapping mechanism from free to trapped states was especially checked in terms of the variance of the shorter lifetime component. Deduced values for τ_c (lifetime of untrapped positrons) and τ_t (lifetime of trapped positrons) were 125±5 psec and 189±10 psec, respectively.