The LHCb VERTEX LOCATOR performance and VERTEX LOCATOR upgrade

LHCb is an experiment dedicated to the study of new physics in the decays of beautyand charm hadrons at the Large Hadron Collider (LHC) at CERN. The Vertex Locator (VELO) isthe silicon detector surrounding the LHCb interaction point. The detector operates in a severe andhighly non-uniform radiation environment. The small pitch and analogue readout result in a bestsingle hit precision of 4 mu m. The upgrade of the LHCb experiment, planned for 2018, will transform the entire readout toa trigger-less system operating at 40 MHz event rate. The vertex detector will have to cope withradiation levels up to 10 super(16) 1 MeVn sub(eq)/cm super(2), more than an order of magnitude higher than thoseexpected at the current experiment. A solution is under development with a pixel detector, basedon the Timepix/Medipix family of chips with 55 x 55 mu m pixels. In addition a micro-strip solutionis also under development, with finer pitch, higher granularity and lower mass than the currentdetector. The current status of the VELO will be described together with recent testbeam results.