LHCb VErtex LOcator (VELO): Module production and performance

LHCb is the dedicated b-hadron experiment at the LHC. At its center is the VErtex LOcator (VELO). Located in a secondary vacuum system within the LHC primary beam vacuum, the VELOʹs primary purpose is to identify and trigger on bottom hadron decays through the precise reconstruction of the primary and secondary vertices. The VELO detector system is presented with special focus on the module specifications, design and fabrication. The production of the 42 VELO modules, which finished in February 2007, is described. The thermal, electrical, and radiation-hard performance of the finished modules is detailed.