A general cold atomic and molecular beam source

We have demonstrated and characterized a high-flux beam source for cold, slow atoms or molecules. The desired species is vaporized using laser ablation, then cooled by thermalization in a cryogenic cell filled with $\sim1$~mTorr ($\sim2\times10^{15}$~cm$^{-3}$) of helium buffer gas. The beam is formed by particles exiting a 3~mm hole in the buffer gas cell. We have characterized the properties of the beam (flux, forward velocity, translational and internal temperatures) for both an atom (Na) and a molecule (PbO) under varying buffer gas density at a cell temperature of $\sim4$~K. We have constructed a magnetic guide to separate the beam from the helium buffer gas and show that the source could be used to load a variety of traps with a wide range of atoms and molecules. We also plan to reduce the cell temperature below 1~K with additional cryogenic refrigeration.