Inversion Temperature in the Separation of Isobaric CO Molecules by Thermal Diffusion

Abstract

In specially constructed thermal diffusion columns separations between the isotopic mixtures ¹²C¹⁸O/¹²C¹⁶O and ¹⁴C¹⁶O/¹²C¹⁶O were measured at average temperatures ranging from T=260°Κ to T=465°K. At temperatures above 320°K ¹⁴C¹⁶O concentrates more strongly in the cold region than ¹²C¹⁸O. Below this temperature the opposite effect is taking place: the thermal diffusion factor α(¹²C¹⁸O/¹²C¹⁶O) is greater than α'(¹⁴C¹⁶O/¹²C¹⁶O). All separations were carried out at temperatures for which the heavier molecule concentrates in the cold region.