A CONTINUOUS BEAM OF SLOW, COLD CESIUM ATOMS MAGNETICALLY EXTRACTED FROM A 2D MAGNETOOPTICAL TRAP

Starting from a 2D magneto-optical trap where cesium atoms are permane ntly subjected to 3D sub-Doppler cooling and 2D magneto-optical trappi ng, we have produced a beam of cold atoms continuously extracted along the trap axis. The simplest extraction mechanism, presently used, is the drift velocity induced by a constant magnetic field. We have used this continuous beam of atoms to produce Ramsey fringes in a microwave cavity as a first demonstration of an atomic resonator operating cont inuously with laser cooled atoms. The shape of the resonance pattern a llows an estimate of the axial temperature, typically 200 mu K. The av erage velocity can be adjusted from 0.7 to 3 m/s; the trap-to-atomic-b eam conversion efficiency is close to one.