The ATLAS Insertable B-Layer (IBL) Project

Preparing the hight luminosity LHC phase, the ATLAS experiment will upgrade his Pixel tracking system with the installation of a new pixel layer. The new sub detector, called the Insertable B-layer (IBL), will be installed during the LHC first shut down in 2013-2014, in between the innermost actual pixel layer and the beampipe. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip FE-I4 and two different silicon sensor technologies, planar and 3D have been developed. Furthermore, the physics performance should be improved through the reduction of pixel size and a new mechanical support using lightweight staves. Two pre-series staves were made in order to qualify the assembly procedure, the loaded module electrical integrity and the read-out chain before going into production.