  We present the results of a study of the diffusion of Rb atoms in paraffin -
coated resonant vapor cells. We have modeled the Rb diffusion both in the cell
and in the coating, assuming that the main loss of Rb atoms is due to the
physical absorption of the atoms by the glass substrate. It is demonstrated
that the equilibrium atomic density in the cell is a monotonic function of the
thickness of the paraffin coating: the density increases with an increase in
the thickness of the coating. The diffusion coefficient for rubidium in
paraffin thin films has been determined to be equal to 4,7*10^-7 cm^2/s. The
results of the experiment might be useful for a better understanding of the
details involved in the processes of the interaction of alkali atoms with a
paraffin coating.
