Feasibility study of non-destructive defect analysis by positron annihilation lifetime measurement

Abstract We examined the feasibility of on-site non-destructive defect analysis using positron annihilation lifetime measurement. This analysis requires a short measurement time and lattice defect information has to be extracted from positron lifetime data that involve high statistical uncertainties. In this study, we simulated positron lifetime spectra for a short measurement of approximately 1 min, using experimental positron lifetimes of shot-peened stainless steel, and studied the variations of the center-of-gravity positron lifetime, the “mean” positron lifetime and the shift in the starting time (Δ T 0 ) with the positron trapping rate into defects, which is a physical quantity proportional to the lattice defect density. As a result, distinguishing the positron lifetime spectra of different trapping rates in a range of up to 1 × 10 11 s −1 was possible by creating a 2D plot of the “mean” positron lifetime and Δ T 0 .