The Self-Diffusion Coefficient of Uranium Hexafluoride

Abstract

A method is reported for measuring the self-diffusion coefficient of a vapor by observing with a mass spectrometer the rate at which material enriched in one isotope diffuses into normal material in an apparatus of known geometry. A value of $\ensuremath{\rho}D$ (where $\ensuremath{\rho}$ is the density and $D$ the diffusion constant) was obtained for uranium hexafluoride at 30\ifmmode^\circ\else\textdegree\fi{}C. Knowledge of the viscosity together with the constants reported here allow calculation of the molecular force law.