Two-dimensional magneto-optical trap as a source of slow atoms

We experimentally study the use of two-dimensional magneto-optical trapping (2D-MOT) for the generation of slow beams of cold atoms out of a vapor cell. A particularly high flux of $9\times {10}^9$ rubidium atoms/s at a mean velocity of 8 m/s is obtained using a combination of magneto-optical trapping in two dimensions and Doppler cooling in the third dimension $({2\mathrm{D}}^{+}-\mathrm{MOT}).\mathrm{}$ The resulting width of the velocity distribution is 3.3 m/s [full width at half maximum (FWHM)] with a beam divergence of 43 mrad (FWHM). We investigate the total flux as a function of vapor cell pressure and determine the velocity distribution of our slow atom sources. For comparison, we also realized a low-velocity intense source (LVIS), first reported by Lu et al. [Phys. Rev. Lett. 77, 3331 (1996)]. We find that the ${2\mathrm{D}}^{+}-\mathrm{MOT}$ yields a significantly higher flux than the LVIS, even when used with an order of magnitude less laser power.