Polarization measurement of an atomic hydrogen beam spin-exchanged with optically oriented sodium atoms

The spin-exchange reaction between hydrogen atoms and optically oriented sodium atoms was used to produce a polarized atomic hydrogen beam. The electron-spin polarization of atomic hydrogen beam, which underwent the spin-exchange reaction with the optically oriented sodium atoms, was measured. A beam polarization of -(8.0±0.6)% was obtained when the thickness and polarization of the sodium target were (5.78±0.23) x 1013 atoms/cm2 and -(39.6±1.6)%, respectively. The value of the spin-exchange cross section in the forward scattering direction, whose scattering angle in the laboratory system was less than 1.1deg, was obtained from the experimental results as (3.39±0.34) x 10-15 cm2. This value is almost seven times larger than the theoretical value calculated from the theoretically estimated Na-H potential. (author)