Continuous, dense, highly collimated sodium beam

We have developed a slow, highly collimated, and bright sodium atom beam suitable for orientation and alignment studies in cold collisions. A combination of transverse-optical collimation, longitudinal cooling, rapid decoupling from the longitudinal cooling cycle, and a final “optical-force extrusion” stage produces an atom density of ${\text{1×10}}^{10} {\mathrm{cm}}^{\mathrm{-3}}$ within a beam-divergence solid angle of ${\text{2×10}}^{\text{−6}} \mathrm{sr}.$ Rapid Zeeman-cooler decoupling results in a narrow laboratory velocity distribution of 5 m/s full width at half maximum and a cold binary intrabeam collision temperature of 4 mK.