Thermodynamic Properties of a Monatomic Hydrogen Gas at High Temperatures

Abstract

A study is made of a gas in which the internal and intermolecular degrees of freedom are not separable. Expressions for the partition function and thermodynamic properties are derived for a gas of monatomic hydrogen. The number of bound states of the system is limited by interactions between the hydrogen atoms. The potentials of interaction of hydrogen atoms with protons, electrons, and other hydrogen atoms are estimated, and the partition function is evaluated at a series of densities from 10 to 10—5 amagats. The occupation numbers of bound states and the percent ionization are changed significantly by considering atom—atom and atom—proton interactions, but the value of the partition function is only slightly changed relative to that calculated by considering only the effect of interatomic forces upon the single-atom energies.