Polarized Sodium Nuclei Produced by Laser Optical Pumping with Velocity Changing Collisions

Theoretical and experimental studies of nuclear polarization induced by single-mode---laser optical pumping are reported. The nuclear polarization is shown to depend on the product of laser intensity and buffer-gas pressure. In ²³Na it approaches one at modest laser intensities ({~}100 mW/cm²) for pressures as small as a few hundred millitorr.