Thermal Diffusion in a Loaded Sphere—Smooth Sphere Mixture: A Model for 4He–HT and 3He–HD

Abstract

The kinetic theory of a mixture of loaded spheres and smooth spheres of equal mass is developed as a model for thermal diffusion in the systems ³He–HD, ⁴He–HT, and ⁴He—D₂. The inelastic effects in the loaded‐sphere collisions are sufficient to explain the experimental ``anomalies'' observed in thermal diffusion involving the asymmetric hydrogen isotopes. The effects of spin polarization, though not dominant, are not negligible.