THE CAPTURE PROCESS IN SPHERICAL MAGNETS-OPTICAL TRAPS - EXPERIMENT AND 1D MAGNETIC-FIELD MODELS

The influence of the magnetic field gradient on the number of Cs atoms captured in a three-dimensional magneto-optical trap is investigated both theoretically and experimentally. Two one-dimensional models of t he capture process are proposed, which differ only by the nature of th e assumptions on the effect of Zeeman optical pumping. Transverse cool ing beams are accounted for by a mere modification of the scattering r ate. Comparison with experiment shows that the number of trapped atoms versus laser detuning, laser intensity, laser beam diameter and magne tic field gradient is best predicted by a model including all Zeeman s ubstates of the Cs atoms. Quantitative agreement is within a factor of three in most cases of interest.