The silicon microstrip tracker for CMS

The CMS silicon strip tracker involves about 70 m(2) of instrumented silicon, with approximately 18500 microstrip detectors read out by 5 x 10(6) electronics channels. It has to satisfy a set of stringent requirements imposed by the environment and by the physics expected at the LHC: low cell occupancy 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 structures, chosen to facilitate construction and to allow for easy assembly and maintenance.

This paper describes the silicon microstrip tracker of the CMS experiment at the future LHC. The silicon tracker consists of a barrel part with 5 layers and two endcaps with 10 disks each. About 6500 modules will have to be built, each one carrying two daisy-chained silicon sensors and their front-end electronics: The modules have been designed to be as simple and robust as possible. Radiation damage in the silicon sensors is minimized by cooling the whole system down to -10 degrees C. Safe operation after heavy irradiation will be possible due to the high-voltage capability of the sensors. We expect the sensors: to have a signal-to-noise ratio of 10 at the end of 10 years of LHC running, which still gives an efficiency of almost 100%. RI Krammer, Manfred/A-6508-2010; Servoli, Leonello/E-6766-2012; Azzi, Patrizia/H-5404-2012