Candlestick rubidium beam source

Many atomic physics laboratories rely on beams of alkali atoms for their experiments, for example in the atom optics and laser cooling communities. Rubidium is commonly used, due to the fortunate coincidence of the dipole resonant transition with the optimum output wavelength of low-cost AlGaAs semiconductor lasers. Suitable rubidium beams can easily be produced with effusive ovens, but many experiments require high flux, and with conventional sources this leads to short lifetimes. Recharging of alkali ovens is messy, time consuming, and often dangerous. Recirculating designs, which use some mechanism to recycle those atoms not emitted in the desired beam, have been published for other alkalis such as cesium and sodium. More recently, Vestergaard Hau et al. have developed an elegant recirculating sodium design using capillary action, which they call a ‘‘candlestick.’’ It is compact, and provides high brightness, high flux, good energy efficiency, and long life. In this article we describe a version of the candlestick source developed for rubidium, with several modifications and enhancements, including a cooling system which is needed to maintain the required temperature gradient across the candlestick, improved heating elements, and details of the cleaning procedure and operating conditions which were critical to successful operation.