Performance of ATLAS pixel detector prototype modules

The ATLAS silicon pixel detector is the innermost tracking device of the ATLAS experiment at the LHC consisting of more than 1600 modules for a total sensitive area of about 1.5 m2 and over 70 million pixel cells. The concept is a hybrid of FE-chips bump bonded to the pixel sensor. The elementary pixel cell has 50 μm×400 μm size. Pulse height measurement is provided by the time over threshold technique. The main issue in the design is the radiation hardness of both the sensitive detector and the readout electronics. Assemblies of readout electronics in deep sub-micron technology and oxygenated silicon sensor have been irradiated up to a fluence of 1015 neq/cm2 and a dose of 60 Mrad. The resolution, charge collection and efficiency have been measured in test beams.