Distillation of gas and measurement of spin–lattice relaxation times

The polarization (static or dynamic) of HD material requires very pure HD samples, with H 2 and D 2 impurities concentrations smaller than 0.1%. A new distillation apparatus equipped with a mass spectrometer has been built. It allows reaching such a level of purity and also measurement of the H 2 and D 2 residual concentrations down to 0.05%. The NMR spin–lattice relaxation times T 1 H and T 1 D have also been measured. The apparatus is described as well as the distillation method. T 1 H and T 1 D data as a function of [ H 2 ] and [ D 2 ] concentrations are given, at 0.85 T and 1.8 K.