Temperature and spatial diffusion of atoms cooled in a 3D lin perpendicular to lin bright optical lattice

We present a detailed experimental study of a three-dimensional lin perpend icular to lin bright optical lattice. Measurements of the atomic temperatur e and spatial diffusion coefficients are reported for different angles betw een the lattice beams, i.e. for different lattice constants. The experiment al findings are interpreted with the help of numerical simulations. In part icular we show, both experimentally and theoretically, that the temperature is independent of the lattice constant.