Positron Lifetimes in Deformed Copper

Positron lifetime measurements were performed for Cu samples with different densities of lattice defects. The lifetime spectra were successfully resolved into two components with the help of the well established analysis program. Obtained results were quite consistent with those expected from the trapping model. The positron trapping mechanism from free to trapped states and the initial condition of the model were especially checked. Deduced values obtained for τ c (lifetime of free positrons) and τ t (lifetime of trapped positrons) were 122±5 psec and 176±5 psec, respectively.