The silicon microstrip tracker for CMS

The CMS silicon strip tracker involves about 70 m(2) of instrumented silico n, with approximately 18500 microstrip detectors read out by 5 x 10(6) elec tronics channels. It has to satisfy a set of stringent requirements imposed by the environment and by the physics expected at the LHC: low cell occupa ncy and good resolution, radiation hardness aided by adequate cooling, low mass combined with high stability. These conditions have been incorporated in a highly modular design of the detector modules and their support struct ures, chosen to facilitate construction and to allow for easy assembly and maintenance.