Trapping of Positrons by Dislocations in Aluminum

Abstract
Positron lifetime measurements have been performed in plastically deformed aluminum single crystals. Evidence of a second nonspurious lifetime component has been observed. The results are interpreted as the trapping of positrons by dislocations. The lifetimes are found to be 172 psec in the perfect crystal and 228 psec in a dislocation. The escape probability of trapped positrons is estimated to be zero.