The coefficient of viscosity of atomic hydrogen from 25 to 300 °K

Abstract

The elastic scattering of two H atoms in the singlet ground state has been investigated on the basis of a deep square -well potential, bounded by the long -range van der Waals attrac­tion . Phase shifts with their appropr ate multiples of π are represented fo r L = 0 (1 ) 29. Some phase shifts exhibit a step -like gain of it within creasing wave number . This phenomenonis illustrated by wave function graphs and is discussed . Viscosity cross -sections are given . For scattering in the triplet ground state a Buckingham - Corner form of potential has been used and previously calculated cross -sections have been extrapolated and applied. Effective rigid -sphere diameters have been estimated by the empirical methodof Hirschfelder & Eliason , both for the approximate and accurate potentials . Two curves are given for the temperature dependence of the coefficient of vicosity , one calculated , the other estimated , and the true curve should lie nearer the latter.