NOTE ON THE SPIN-POLARIZATION OF HYDROGEN-ATOMS IN A HELIUM-HYDROGEN GAS-MIXTURE

In a helium-hydrogen mixture at T = 300 K, the polarization degree of hydrogen spins, both electron and nuclear, was determined to be as hig h as (5 +/- 1)%.The role of the main processes giving rise to the form ation of spin-polarized H atoms has been discussed It is shown that an effective transfer of angular momentum from the preliminarily optical ly oriented He(2(3)S(1)) atoms to the H atoms is not due to the direc t chemi-dissociation of the H-2 molecules by the He atoms alone, or d ue to Penning ionization of these molecules followed by the ion-molecu lar rearrangement reaction H-2(+) + H-2 --> H-3(+) + H alone, but to t heir summary action. The relative important of the two mechanisms depe nds on the rotational temperature and total gas pressure.