COOLING MECHANISMS IN POTASSIUM MAGNETOOPTICAL TRAPS

We report on a theoretical and experimental investigation of K-39 magn eto-optical trapping. The small hyperfine splitting characterizing the upper level of the cooling transition affects the cooling mechanism. In order to model the atom-laser inter action, the whole level structu re of the D-2 line has to be taken into account. Two different regimes have been recognized, one optimizing the loading of the trap, the sec ond minimizing the temperature of the atoms. We investigated these two regimes experimentally and found results in agreement with the theore tical predictions.