Simulation of the motion of H$_{2}$ and D$_{2}$ molecules in sextupole magnets

The simulation of the movement of hydrogen and deuterium molecules in the magnetic system of the installation designed to obtain nuclear spin-polarized molecules is produced. For the spatial separation of molecules with different projections of the magnetic moments of spin filtering method in a nonuniform magnetic field, superconducting sextupole magnets are used. The calculation was performed when the induction of the magnetic field near the poles of 3.7 T and the nozzle temperature of the 7K. The simulation showed that the ratio of the polarized flux of hydrogen molecules into the detector to the total flux from the source nozzle is 2.3 $\times$ 10$^{-6}$, and the nuclear polarization is about 100%. For deuterium, the calculations showed that this ratio is 7 times less because of the smallness of the magnetic moment with respect to hydrogen molecules. The graphs of molecular trajectories in the magnetic system and their spatial distribution are presented. The mathematical aspects of the developed computer program algorithm are considered.