Neutron Diffraction Study of Krypton in the Liquid State

Abstract

The angular distribution of 1.05 A neutrons scattered by krypton in the liquid state at temperatures of 117°K, 133°K, 153°K, 183°K, and 210°K is reported. By use of a sample cell fabricated from a single aluminum crystal, it was possible to obtain diffraction patterns up to the critical temperature and pressure. The scattering curves were Fourier transformed to obtain the radial atomic distribution function at each temperature. The number of nearest neighbors calculated from these distribution functions ranges from 8.5 at 117°K to 4.0 at 210°K at distances ranging from 4.02 A to 4.20 A, respectively. A comparison of radial distribution functions from arbitrarily terminated data shows that the ratio of the last zero-atomic-density position to the first atomic-density-maximum position is a function of the amount of intensity data transformed. It also indicates that the width of the bowl of the effective potential in liquid krypton is in approximate quantitative agreement with that of the Lennard-Jones 12:6 potential.