Relaxation of Optically Pumped Cesium Atoms by Different Buffer Gases

Abstract

The decay of spin polarization of optically pumped cesium atoms at room temperature in the inert buffer gases helium, neon, and argon, has been investigated at different buffer gas pressures. It has been found that the decay of the spin polarization is not a simple exponential but can be described as the sum of two exponentially decaying modes, which are interpreted as two diffusion modes. The diffusion coefficients for cesium in helium, neon, and argon are found to be 0.37, 0.24, and 0.19 cm²/sec, and the collision depolarization cross sections are 2.5×10^—24, 8.4×10^—24, and 26×10^—24 cm², respectively.