The relationship between void size and positron lifetime in neutron irradiated molybdenum

A number of molybdenum specimens, each containing a characteristic void size spectrum, have been subjected to positron lifetime measurements. Although the average void size varied in radius from 9 Å to 45 Å the long positron lifetime in the specimens was remarkably constant with τ₂ = 465±5 ps. Therefore for the range of void sizes examined, this parameter appears to be independent of the void size.