Fig. 7

Mass spectra in two separated experiments, below (a) and above (b) \(\lambda\)-transition. Spectra were registered for the rectification column from Fig. 6: (a) mass spectrum for 1.93 K at the bottom of column and (b) mass spectrum for 3.3 K at the bottom of the column—the separation efficiency depends little on whether the rectification is below or above \(\lambda\)-transition. The presence of hydrogen peaks at masses 1 and 2 are explained in our previous paper¹⁷.