One of the main limitations of cesium atomic fountains has been the coldcollision frequency shift. By using a method based on a transfer of populationby adiabatic passage allowing to prepare cold atomic samples with a welldefined ratio of atomic density as well as atom number the collisional shift iscontrolled at the 10E-3 of its value. A calibration of Zeeman sub-statescontribution to the clock shift as a function of the field has been performed.Feshbach resonances have been observed for the first time at very low magneticfield and with a very good resolution. A Monte Carlo simulation has beenperformed and could fit properly some of experimental data. This constrainssome parameters of the theory of collisions.
展开▼
