A Silicon Inner Tracker for the LHCb Experiment

The future LHCb experiment operated at the Large Hadron Collider (LHC) will perform pre- cision measurements of CP violation parameters and rare decays in the B system. A silicon strip detector is being developed for the inner part of the LHCb tracking system covering the re- gion near to the beam pipe. Different prototype silicon sensors with a large strip pitch between 198 m and 240 m were tested for the LHCb Inner Tracker. The electrical characteristics of the sensors are presented. Laboratory and test beam results on resolution, signal-to-noise and efficiency are discussed. Fast readout electronics have been used in order to meet the LHCb operational requirements. It has been found that the efficiency, especially in the inter-strip gap, is very sensitive to different tested geometries. The results demonstrate that sensors with a strip pitch of about 200 m and a large ratio of strip width over pitch comply with the requirements of the LHCb Inner Tracker and ensure a reliable operation of the detector. Studies on different readout chips were performed in order to identify the optimal front-end design for the final chip.