Distillation column

Xenon gas used to study dark matter has to be free of contaminants as much as possible, especially from radioactive gases, like Radon and Krypton. Evaporations and condensations are carried out to remove them. Xenon, Krypton and Radon have different properties in both phases, liquid or gaseous, that are function of pressure and temperature: by acting on these latter parameters, the gaseous Krypton and liquid Radon are extracted from the top and from the bottom of the distillation column, respectively.