Temperature and pressure dependence of positron mean lives in cadmium

Positron lifetimes have been measured in cadmium at temperatures of 77K and 296 K and at pressures of up to 9.8 kbar. The positron lifetime at 296 K and 9.8 kbar is 178 +- 2 ps, significantly longer than the lifetime of 170 +- 2 ps observed at 77 K and 0 kbar, even though the volume of the sample is smaller in the former case. This result suggests that the effect of temperature is more than that of a simple volume change. (author)