Apparatus for Concentration of He3 by Thermal Diffusion

Abstract

A multistage thermal diffusion apparatus for the concentration of He³ is described. Included is a novel three‐stage, all‐metal column based on a G. E. Calrod heater. Concentration was carried only to a He³/He⁴ ratio of 0.05 percent, a factor of 3.3×10³. The performance indicates the importance of having the hot wall in concentric cylinder columns made of metal of good thermal conductivity to minimize azimuthal temperature gradients which can markedly increase parasitic remixing of the gas if a metal such as stainless steel is used.