HIGH-DENSITY TRAPPING OF CESIUM ATOMS IN A DARK MAGNETOOPTICAL TRAP

We have confined magneto-optically trapped cesium atoms to densities o f nearly 10(12) cm(-3) by directing most of the population to a hyperf ine level which does not interact with the trapping light. This compre ssion represents almost an order of magnitude improvement on the best density we have been able to attain in a conventional magneto-optical trap. In previous work such improvements in density have only been rep orted for much lighter sodium. We discuss and demonstrate the difficul ties in applying the technique to a heavy alkalimetal atom and the lim its that are imposed on the best combination of density and temperatur e that can be produced. We present a simple model that accurately repr oduces the density behavior, and justify its basic assumptions by Mont e Carlo simulation.