Upgrade of the CMS Tracker

A major upgrade of the CMS experiment at the LHC is planned to exploit future increases in LHC luminosity beyond the nominal 1034 cm2 s−1. The LHC upgrades will be made in two stages: Phase-1 to achieve 3×1034 cm2 s−1 and Phase-2 aiming for 1035 cm2 s−1. To maintain excellent detector performance, CMS is obliged to meet these upgrades with improvements to the detector systems, particularly the Tracker. In Phase-1, only the Pixel system will be upgraded, improving performance whilst also minimizing the material within the sensitive volume. For the Phase-2 upgrade, the entire Tracker will have to be replaced. The present level of tracking performance should be maintained under SLHC conditions, and a new and very challenging requirement is that the Tracker should also contribute to the first level trigger.