The tracking system of the ALICE dimuon spectrometer

The ALICE Muon Spectrometer is mainly dedicated to the measurement of the production of the J//spl psi/, and Y families through their decay into muon pairs, in Pb-Pb collisions. In this paper we give a description of the dimuon tracking system, mainly concentrating on the modular CSC chambers which occupy the last three stations. The R&D phase is now almost over and the production of the final modules started. A description of the main performances of the detectors based on test beam results on prototypes will be given.