Cooling and polarization of a sodium atomic beam by a two mode laser

Abstract

Abstract. Cooling and optical pumping by a circularly polarized two mode laser is applied to a Na atomic beam in transverse geometry. The low velocity components of the beam are transversly cooled to the Doppler limit temperature of 240 btK and are simultaneously spin polarized for more than 90%. PACS: 32.80.P Scattering experiments with subthermal spin polarized atoms in the ground state open a new field of interesting physics [ 1]. From the measured total cross section the long range interatomic potential can be determined. Measuring the differential cross section offers the possibility to investigate hyperfine decoupling processes during the scattering with collision energies about equal to the Na ground state hyperfine splitting (1772 MHz).For information about the scattered particles being distinguishable or undistinguishable we have to manipulate the atomic spin polarization.We have set up an experiment to cool and polarize a Na atomic beam in transverse geometry, i.e., two counterpropagating laser beams of the same circular polarizations illuminate the Na beam at right angle [2] (Fig.