Analysis procedures for annihilation energy spectra with enhanced sensitivity to positron localization

Abstract

Annihilation energy spectra in a variety of defected and defect-free metal samples have been measured repeatedly in order to test the relative sensitivity of several lineshape parameters to changes induced by positron localization. Commonly used measures of the lineshape, such as the variance, are shown to be decidedly inferior to parameters which weight the data from each channel in accord with its sensitivity to positron trapping. The counting time required for a given precision can be approximately halved by using an appropriately weighted shape parameter.