Continuous, dense, highly collimated sodium beam

We have developed a slow, highly collimated, and bright sodium atom beam su itable for orientation and alignment studies in cold collisions. A combinat ion of transverse-optical collimation, longitudinal cooling, rapid decoupli ng from the longitudinal cooling cycle, and a final "optical-force extrusio n" stage produces an atom density of 1 x 10(10) cm(-3) within a beam-diverg ence solid angle of 2 x 10(-6) sr. Rapid Zeeman-cooler decoupling results i n a narrow laboratory velocity distribution of 5 m/s full width at half max imum and a cold binary intrabeam collision temperature of 4 mK. (C) 2000 Am erican Institute of Physics. [S0034-6748(00)02110-9].