The LHCb vertex detector

LHCb is a next generation experiment for the study of CP violation in B-meson decays. Efficient triggering is a key issue in this 14 TeV proton collision experiment with a bunch crossing frequency of 40 MHz. The vertex detector delivers full analog event information at a rate of 1 MHz to the level-1 trigger for identification of tracks with a high impact parameter. The silicon micro-strip sensors of the vertex detector are installed in a secondary vacuum close to the beams. They must be retracted during beam injection. The signals of the strips are read out with radiation hard analog chips called ‘Beetles’. The performance of the Beetle1.1 was measured in a test beam. System tests are planned for 2004.