Spin-Exchange Collisions of the Ground State of Cs Atoms in a High Magnetic Field

Cs atoms were optically pumped with a Ti:sapphire laser in a magnetic field of 1.516T. Steady absorption spectra and populations of Zeeman sublevels of the ground state of Cs in N₂ gas at various pressures (5, 40, and 80 Torr) were obtained. The results show that in a high magnetic field, the combined electron-nuclear spin transition (flip-flop transition), which is mainly induced by the collision modification δa( J . I ) of hyperfine interaction, is an important relaxation mechanism at high buffer-gas pressures.