The ALICE Inner Tracking System Upgrade

The long term plan of ALICE (A Large Ion Collider Experiment) at the CERN Large Hadron Collider (LHC) is a detailed investigation and characterisation of the Quark-Gluon Plasma (QGP). ALICE has devised a comprehensive upgrade strategy to enhance its physics capabilities and to exploit the LHC running conditions after the second long shutdown of the LHC scheduled in 2019-20. The upgraded ALICE will focus on high precision measurements of rare probes over a wide range of momenta, which will significantly improve the performance with respect to the present experimental set up. The upgrade strategy is based on the fact that after LS2 LHC will progressively increase its luminosity with Pb beams eventually reaching an interaction rate of about 50 kHz. To exploit the new LHC capabilities, several existing detectors will undergo a substantial upgrade and new detectors will be added. Within this upgrade strategy, the Inner Tracking System (ITS) upgrade forms an important cornerstone, providing precise measurements for heavy-flavour interactions with the QGP medium and for the production of thermal photons and low-mass dileptons. The present ITS will be replaced by a new seven-layer ITS consisting of Monolithic Active Pixel Sensors (MAPS) with highly improved tracking and vertexing abilities. In this contribution, an overview of the ITS upgrade, the technical developments for the detector elements and some performance studies are presented.