Variation in Positron Lifetime with Pressure

Abstract

The mean life of the long-lived component of positrons annihilating in various solids and liquids has been measured at pressures up to 6000 atm and temperatures up to 200\ifmmode^\circ\else\textdegree\fi{}C. At fixed temperature, the mean life decreases exponentially with the change in volume due to increasing pressure. At fixed volume, the lifetime decreases with increasing temperature. A qualitative explanation of the variation is presented.