  We report on the experimental realization of a Bragg reflector for guided
matter waves. A Bose-Einstein condensate with controlled velocity distribution
impinges onto an attractive optical lattice of finite length and directly
probes its band structure. We study the dynamics of the scattering by this
potential and compare the results with simple one-dimensional models. We
emphasize the importance of taking into account the gaussian envelope of the
optical lattice which gives rise to Bragg cavity effects. Our results are a
further step towards integrated atom optics setups for quasi-cw matter waves.
