Positron Lifetime Study of Molybdenum Neutron-Irradiated at Various Temperatures.

摘要

Positron lifetime measurements reveal that neutron irradiation at 350 and 400 C can produce sub-electron microscopic voids in Mo. The results show that the lifetime in voids reaches a saturation value with increasing void size to a dimension less than 20 A. It is suggested that the difference among known data for tau sub 2 approx. > 450 ps can be attributed to differences in the metal-void interface and gaseous conditions within the void. (Author)