Positron lifetimes in high dose neutron irradiated molybdenum and TZM

Positron lifetime measurements are reported for a series of neutron irradiated molybdenum and TZM samples whose void and dislocation parameters had been well characterised by transmission electron microscopy. Among the samples were some where irradiation induced void shrinkage had taken place and some in which the dislocation loop density was particularly high. This provided an opportunity to correlate the short lifetime positron component with dislocation trapping. However, no success was obtained and instead it seems necessary to consider other traps such as vacancy-gas complexes. (Auth.)