  Alkali metal dispensers have become an indispensable tool in the production
of atomic vapors for magnetometry, alkali vapor cell clocks, and laser cooling
experiments. A primary advantage of these dispensers is that they contain
alkali metal in an inert form that can be exposed to air without hazard.
However, their high temperature of operation (>600 C) is undesirable for many
applications, as it shifts the atomic speed distribution to higher values and
presents a radiative heat source that can raise the temperature of its
surroundings. For this reason, dispensers are typically not used in
line-of-sight applications such as atomic beam generation. In this work, we
present an integrated rubidium dispenser collimating device with a thickness of
only 2 mm that produces a beam of atoms traveling primarily in the forward
direction. We find that the collimator plate serves to both shield the
dispenser's radiation as well as to moderate the velocity of the atomic beam so
that the measured longitudinal speed distribution is comparable to that of an
ordinary alkali oven at only a slightly elevated temperature of 200 C. To
confirm our theory, we also constructed another compact apparatus consisting of
a dispenser and a silicon collimator and the measurements support our
conclusion. Our integrated dispenser collimator will particularly be useful in
integrated photonics and cavity QED on chip, where a localized, directed source
of Rb vapor in small quantities is needed.
