Overview of the Insertable B-Layer (IBL) Project of the ATLAS experiment at the Large Hadron Collider

The ATLAS experiment will upgrade its Pixel Detector with the installation of a new pixel layer in 2014. The new sub-detector, named Insertable B-layer (IBL), will be installed between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while targeting for a low material budget should be imposed, pushing for a new mechanical support using lightweight staves and a CO2 based cooling system. An overview of the IBL project as well as the present experience in its construction will be presented, focusing on the staves production, qualification of the assembly procedure, integration of the staves around the beam pipe and commissioning of the detector.