  We report on experimental studies of superconductor (Nb) - normal metal (Cu)
- superconductor (Nb) junctions with dirty interfaces between the different
materials. By using a set of simultaneously prepared samples, we investigated
the thickness dependence as well as the temperature dependence of the critical
currents in the junctions. Good agreement between the decay of the measured
critical currents and theoretical calculations was obtained without any fitting
parameters.
