Abstract
The P23 metastable atoms of neon have been optically oriented. This represents the first case of the optical pumping of non-S state atoms. The optical-pumping process is described, and depolarization cross sections for collisions with ground-state neon and ground-state helium atoms measured. The cross section for collisional depolarization with helium is 4.30 ± 0.22 × 1017 cm2, and with neon is 166 ± 8 × 1017 cm2 at 300°K. The metastable P23 atoms of Ar and Xe have also been optically pumped. As the polarizability of the noble-gas buffer increases, the collisional depolarization cross section approaches the diffusion cross section.