The ATLAS Insertable B-Layer Pixel Detector

ATLAS currently develops a new pixel detector for the first upgrade of its tracking system: The ATLAS Insertable B-Layer Pixel detector (IBL). The new layer will be inserted between the inner most layer of the current pixel detector and a new beam pipe. The sensors are placed at a radius of 3.4 cm. The expected high radiation levels and high hit occupancy require new developments for front-end chip and sensors which can stand radiation levels beyond 5$ imes$10$^{15}$ n$_{eq}$/cm$^{2}$ . ATLAS has developed the new FEI4 chip and new silicon sensors to be used as pixel modules. Furthermore a new lightweight support and cooling structure was developed, which minimizes the overall radiation length and allows detector cooling with CO$_{2}$ at -40 $^{circ}$C coolant temperature. Currently the overall integration and installation procedure is being developed and tested ready for installation in 2013. The paper summarizes the current state of development of IBL modules, first preliminary test results of the new chip with new sensors, the construction of its pixel staves and overall support structure. It will conclude with an outline of the challenges for its installation in the present ATLAS detector system.