  We numerically investigate the one-dimensional transport of Bose-Einstein
condensates in the context of guided atom lasers using a mean-field description
of the condensate in terms of a spatially discretized Gross-Pitaevskii
equation. We specifically consider a waveguide configuration in which spatial
inhomogeneities and nonvanishing atom-atom interactions are restricted to a
spatially localized scattering region of finite extent. We show how the method
of smooth exterior complex scaling can be implemented for this particular
configuration in order to efficiently absorb the outgoing flux within the
waveguide. A numerical comparison with the introduction of a complex absorbing
potential as well as with the analytically exact elimination of the dynamics of
the free non-interacting motion outside the scattering region, giving rise to
transparent boundary conditions, clearly confirms the accuracy and efficiency
of the smooth exterior complex scaling method.
